9 years agoerr.h: add __must_check to error pointer handlers
Jani Nikula [Mon, 24 May 2010 21:33:00 +0000]
err.h: add __must_check to error pointer handlers

Add __must_check to error pointer handlers to have the compiler warn about
mistakes like:

if (err)
ERR_PTR(err);

It found two bugs:

Mar 12 Nikula Jani [PATCH] enclosure: fix error path - actually return ERR_PTR() on error
Mar 12 Nikula Jani [PATCH] sunrpc: fix error path - actually return ERR_PTR() on error

Signed-off-by: Jani Nikula <ext-jani.1.nikula@nokia.com>
Cc: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agocpuidle: add a repeating pattern detector to the menu governor
Arjan van de Ven [Mon, 24 May 2010 21:32:59 +0000]
cpuidle: add a repeating pattern detector to the menu governor

Currently, the menu governor uses the (corrected) next timer as key item
for predicting the idle duration.

It turns out that there are specific cases where this breaks down: There
are cases where we have a very repetitive pattern of idle durations, where
the idle period is pretty much the same, for reasons completely unrelated
to the next timer event.  Examples of such repeating patterns are network
loads with irq mitigation, the mouse moving but in theory also the wifi
beacons.

This patch adds a relatively simple detector for such repeating patterns,
where the standard deviation of the last 8 idle periods is compared to a
threshold.

With this extra predictor in place, measurements show that the DECAY
factor can now be increased (the decaying average will now decay slower)
to get an even more stable result.

[arjan@infradead.org: fix bug identified by Frank]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Corrado Zoccolo <czoccolo@gmail.com>
Cc: Frank Rowand <frank.rowand@am.sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomn10300: set ARCH_KMALLOC_MINALIGN
FUJITA Tomonori [Mon, 24 May 2010 21:32:58 +0000]
mn10300: set ARCH_KMALLOC_MINALIGN

Architectures that handle DMA-non-coherent memory need to set
ARCH_KMALLOC_MINALIGN to make sure that kmalloc'ed buffer is DMA-safe: the
buffer doesn't share a cache with the others.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomn10300: use generic atomic.h
Mathieu Desnoyers [Mon, 24 May 2010 21:32:56 +0000]
mn10300: use generic atomic.h

asm-generic/atomic.h has been derived from the mn10300 implementation.
Remove the now duplicated mn10300 implementation by including the generic
version instead.

This adds cmpxchg_local() and cmpxchg64_local() for free to the
architecture, as they are implemented in asm-generic/atomic.h.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Peter Fritzsche <peter.fritzsche@gmx.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jamie Lokier <jamie@shareable.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Keith M Wesolowski <wesolows@foobazco.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agom68knommu: fix broken use of BUAD_TABLE_SIZE in 68328serial driver
Greg Ungerer [Mon, 24 May 2010 21:32:55 +0000]
m68knommu: fix broken use of BUAD_TABLE_SIZE in 68328serial driver

Commit 8b505ca8e2600eb9e7dd2d6b2682a81717671374 ("serial: 68328serial.c:
remove BAUD_TABLE_SIZE macro") misses one use of BAUD_TABLE_SIZE.  So the
resulting 68328serial.c does not compile:

drivers/serial/68328serial.c: In function `m68328_console_setup':
drivers/serial/68328serial.c:1439: error: `BAUD_TABLE_SIZE' undeclared (first use in this function)
drivers/serial/68328serial.c:1439: error: (Each undeclared identifier is reported only once
drivers/serial/68328serial.c:1439: error: for each function it appears in.)

Fix that last use of it.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Cc: Thiago Farina <tfransosi@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agofrv: set ARCH_KMALLOC_MINALIGN
FUJITA Tomonori [Mon, 24 May 2010 21:32:54 +0000]
frv: set ARCH_KMALLOC_MINALIGN

Architectures that handle DMA-non-coherent memory need to set
ARCH_KMALLOC_MINALIGN to make sure that kmalloc'ed buffer is DMA-safe: the
buffer doesn't share a cache with the others.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agofrv: extend gdbstub to support more features of gdb
David Howells [Mon, 24 May 2010 21:32:54 +0000]
frv: extend gdbstub to support more features of gdb

Extend gdbstub to support more features of gdb remote protocol to keep
gdb-7 and emacs gud mode happy:

 (*) The D command.  Detach debugger.

 (*) The H command.  Handle setting the target thread by ignoring it.

 (*) The qAttached command.  Indicate we 'attached' to an existing process.

 (*) The qC command.  Indicate that the current thread ID is 0.

 (*) The qOffsets command.  Indicate that no relocation has been done.

 (*) The qSymbol:: command.  Indicate that we're not interested in looking up
     any symbol addresses.

 (*) The qSupported command.  Indicate the maximum packet size and the fact
     that reverse step and continue aren't supported.

 (*) The vCont? command.  Indicate that we don't support any of its variants.

Also make it possible to trace the commands and replies without tracing
the individual character I/O.

[akpm@linux-foundation.org: make gdbstub_handle_query() static]
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: make lowmem_page_address() use PFN_PHYS() for improved portability
Chris Metcalf [Mon, 24 May 2010 21:32:53 +0000]
mm: make lowmem_page_address() use PFN_PHYS() for improved portability

This ensures that platforms with lowmem PAs above 32 bits work correctly
by avoiding truncating the PA during a left shift.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: Barry Song <21cnbao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomem-hotplug: fix potential race while building zonelist for new populated zone
Haicheng Li [Mon, 24 May 2010 21:32:52 +0000]
mem-hotplug: fix potential race while building zonelist for new populated zone

Add global mutex zonelists_mutex to fix the possible race:

     CPU0                                  CPU1                    CPU2
(1) zone->present_pages += online_pages;
(2)                                       build_all_zonelists();
(3)                                                               alloc_page();
(4)                                                               free_page();
(5) build_all_zonelists();
(6)   __build_all_zonelists();
(7)     zone->pageset = alloc_percpu();

In step (3,4), zone->pageset still points to boot_pageset, so bad
things may happen if 2+ nodes are in this state. Even if only 1 node
is accessing the boot_pageset, (3) may still consume too much memory
to fail the memory allocations in step (7).

Besides, atomic operation ensures alloc_percpu() in step (7) will never fail
since there is a new fresh memory block added in step(6).

[haicheng.li@linux.intel.com: hold zonelists_mutex when build_all_zonelists]
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Andi Kleen <andi.kleen@intel.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomem-hotplug: avoid multiple zones sharing same boot strapping boot_pageset
Haicheng Li [Mon, 24 May 2010 21:32:51 +0000]
mem-hotplug: avoid multiple zones sharing same boot strapping boot_pageset

For each new populated zone of hotadded node, need to update its pagesets
with dynamically allocated per_cpu_pageset struct for all possible CPUs:

    1) Detach zone->pageset from the shared boot_pageset
       at end of __build_all_zonelists().

    2) Use mutex to protect zone->pageset when it's still
       shared in onlined_pages()

Otherwises, multiple zones of different nodes would share same boot strapping
boot_pageset for same CPU, which will finally cause below kernel panic:

  ------------[ cut here ]------------
  kernel BUG at mm/page_alloc.c:1239!
  invalid opcode: 0000 [#1] SMP
  ...
  Call Trace:
   [<ffffffff811300c1>] __alloc_pages_nodemask+0x131/0x7b0
   [<ffffffff81162e67>] alloc_pages_current+0x87/0xd0
   [<ffffffff81128407>] __page_cache_alloc+0x67/0x70
   [<ffffffff811325f0>] __do_page_cache_readahead+0x120/0x260
   [<ffffffff81132751>] ra_submit+0x21/0x30
   [<ffffffff811329c6>] ondemand_readahead+0x166/0x2c0
   [<ffffffff81132ba0>] page_cache_async_readahead+0x80/0xa0
   [<ffffffff8112a0e4>] generic_file_aio_read+0x364/0x670
   [<ffffffff81266cfa>] nfs_file_read+0xca/0x130
   [<ffffffff8117b20a>] do_sync_read+0xfa/0x140
   [<ffffffff8117bf75>] vfs_read+0xb5/0x1a0
   [<ffffffff8117c151>] sys_read+0x51/0x80
   [<ffffffff8103c032>] system_call_fastpath+0x16/0x1b
  RIP  [<ffffffff8112ff13>] get_page_from_freelist+0x883/0x900
   RSP <ffff88000d1e78a8>
  ---[ end trace 4bda28328b9990db ]

[akpm@linux-foundation.org: merge fix]
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Andi Kleen <andi.kleen@intel.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomem-hotplug: separate setup_per_cpu_pageset() into separate functions
Wu Fengguang [Mon, 24 May 2010 21:32:49 +0000]
mem-hotplug: separate setup_per_cpu_pageset() into separate functions

No behavior change here.

Move some of setup_per_cpu_pageset() code into a new function
setup_zone_pageset() that will be useful for memory hotplug.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Reviewed-by: Andi Kleen <andi.kleen@intel.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: fix NR_SECTION_ROOTS == 0 when using using sparsemem extreme.
Marcelo Roberto Jimenez [Mon, 24 May 2010 21:32:47 +0000]
mm: fix NR_SECTION_ROOTS == 0 when using using sparsemem extreme.

Got this while compiling for ARM/SA1100:

mm/sparse.c: In function '__section_nr':
mm/sparse.c:135: warning: 'root' is used uninitialized in this function

This patch follows Russell King's suggestion for a new calculation for
NR_SECTION_ROOTS.  Thanks also to Sergei Shtylyov for pointing out the
existence of the macro DIV_ROUND_UP.

Atsushi Nemoto observed:
: This fix doesn't just silence the warning - it fixes a real problem.
:
: Without this fix, mem_section[] might have 0 size so mem_section[0]
: will share other variable area.  For example, I got:
:
c030c700 b __warned.16478
c030c700 B mem_section
c030c701 b __warned.16483
:
: This might cause very strange behavior.  Your patch actually fixes it.

Signed-off-by: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agohighmem: remove unneeded #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT for debug_kmap_atomic()
Akinobu Mita [Mon, 24 May 2010 21:32:46 +0000]
highmem: remove unneeded #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT for debug_kmap_atomic()

In f4112de6b679d84bd9b9681c7504be7bdfb7c7d5 ("mm: introduce
debug_kmap_atomic") I said that debug_kmap_atomic() needs
CONFIG_TRACE_IRQFLAGS_SUPPORT.

It was wrong.  (I thought irqs_disabled() is only available when the
architecture has CONFIG_TRACE_IRQFLAGS_SUPPORT)

Remove the #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT check to enable
kmap_atomic() debugging for the architectures which do not have
CONFIG_TRACE_IRQFLAGS_SUPPORT.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoinclude/linux/gfp.h: fix coding style
matt mooney [Mon, 24 May 2010 21:32:45 +0000]
include/linux/gfp.h: fix coding style

Add parenthesis in a define.  This doesn't change functionality.

checkpatch errors:
1) white space fixes
2) add spaces after comas

Signed-off-by: matt mooney <mfm@muteddisk.com>
Cc: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoinclude/linux/gfp.h: spelling fixes
matt mooney [Mon, 24 May 2010 21:32:44 +0000]
include/linux/gfp.h: spelling fixes

Fix minor spelling errors in a few comments; no code changes.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Cc: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agocpu/mem hotplug: enable CPUs online before local memory online
minskey guo [Mon, 24 May 2010 21:32:41 +0000]
cpu/mem hotplug: enable CPUs online before local memory online

Enable users to online CPUs even if the CPUs belongs to a numa node which
doesn't have onlined local memory.

The zonlists(pg_data_t.node_zonelists[]) of a numa node are created either
in system boot/init period, or at the time of local memory online.  For a
numa node without onlined local memory, its zonelists are not initialized
at present.  As a result, any memory allocation operations executed by
CPUs within this node will fail.  In fact, an out-of-memory error is
triggered when attempt to online CPUs before memory comes to online.

This patch tries to create zonelists for such numa nodes, so that the
memory allocation for this node can be fallback'ed to other nodes.

[akpm@linux-foundation.org: remove unneeded export]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: minskey guo<chaohong.guo@intel.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agovmscan: remove isolate_pages callback scan control
Johannes Weiner [Mon, 24 May 2010 21:32:40 +0000]
vmscan: remove isolate_pages callback scan control

For now, we have global isolation vs.  memory control group isolation, do
not allow the reclaim entry function to set an arbitrary page isolation
callback, we do not need that flexibility.

And since we already pass around the group descriptor for the memory
control group isolation case, just use it to decide which one of the two
isolator functions to use.

The decisions can be merged into nearby branches, so no extra cost there.
In fact, we save the indirect calls.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agovmscan: remove all_unreclaimable scan control
Johannes Weiner [Mon, 24 May 2010 21:32:40 +0000]
vmscan: remove all_unreclaimable scan control

This scan control is abused to communicate a return value from
shrink_zones().  Write this idiomatically and remove the knob.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: document follow_page()
Johannes Weiner [Mon, 24 May 2010 21:32:39 +0000]
mm: document follow_page()

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agofs-writeback: check sync bit earlier in inode_wait_for_writeback
Richard Kennedy [Mon, 24 May 2010 21:32:38 +0000]
fs-writeback: check sync bit earlier in inode_wait_for_writeback

When wb_writeback() hasn't written anything it will re-acquire the inode
lock before calling inode_wait_for_writeback.

This change tests the sync bit first so that is doesn't need to drop &
re-acquire the lock if the inode became available while wb_writeback() was
waiting to get the lock.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: introduce free_pages_prepare()
KOSAKI Motohiro [Mon, 24 May 2010 21:32:38 +0000]
mm: introduce free_pages_prepare()

free_hot_cold_page() and __free_pages_ok() have very similar freeing
preparation.  Consolidate them.

[akpm@linux-foundation.org: fix busted coding style]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agovmscan: page_check_references(): check low order lumpy reclaim properly
KOSAKI Motohiro [Mon, 24 May 2010 21:32:37 +0000]
vmscan: page_check_references(): check low order lumpy reclaim properly

If vmscan is under lumpy reclaim mode, it have to ignore referenced bit
for making contenious free pages.  but current page_check_references()
doesn't.

Fix it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoreadahead.c: fix comment
Huang Shijie [Mon, 24 May 2010 21:32:36 +0000]
readahead.c: fix comment

Fix a wrong comment over page_cache_async_readahead().

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agovmscan: prevent get_scan_ratio() rounding errors
Shaohua Li [Mon, 24 May 2010 21:32:36 +0000]
vmscan: prevent get_scan_ratio() rounding errors

get_scan_ratio() calculates percentage and if the percentage is < 1%, it
will round percentage down to 0% and cause we completely ignore scanning
anon/file pages to reclaim memory even the total anon/file pages are very
big.

To avoid underflow, we don't use percentage, instead we directly calculate
how many pages should be scaned.  In this way, we should get several
scanned pages for < 1% percent.

This has some benefits:

1. increase our calculation precision

2.  making our scan more smoothly.  Without this, if percent[x] is
   underflow, shrink_zone() doesn't scan any pages and suddenly it scans
   all pages when priority is zero.  With this, even priority isn't zero,
   shrink_zone() gets chance to scan some pages.

Note, this patch doesn't really change logics, but just increase
precision.  For system with a lot of memory, this might slightly changes
behavior.  For example, in a sequential file read workload, without the
patch, we don't swap any anon pages.  With it, if anon memory size is
bigger than 16G, we will see one anon page swapped.  The 16G is calculated
as PAGE_SIZE * priority(4096) * (fp/ap).  fp/ap is assumed to be 1024
which is common in this workload.  So the impact sounds not a big deal.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: consider the entire user address space during node migration
Greg Thelen [Mon, 24 May 2010 21:32:33 +0000]
mm: consider the entire user address space during node migration

Use mm->task_size instead of TASK_SIZE to ensure that the entire user
address space is migrated.  mm->task_size is independent of the calling
task context.  TASK SIZE may be dependant on the address space size of the
calling process.  Usage of TASK_SIZE can lead to partial address space
migration if the calling process was 32 bit and the migrating process was
64 bit.

Here is the test script used on 64 system with a 32 bit echo process:

  mount -t cgroup none /cgroup -o cpuset
  cd /cgroup

  mkdir 0
  echo 1 > 0/cpuset.cpus
  echo 0 > 0/cpuset.mems
  echo 1 > 0/cpuset.memory_migrate

  mkdir 1
  echo 1 > 1/cpuset.cpus
  echo 1 > 1/cpuset.mems
  echo 1 > 1/cpuset.memory_migrate

  echo $$ > 0/tasks
  64_bit_process &
  pid=$!

  echo $pid > 1/tasks   # This does not migrate all process pages without
                        # this patch.  If 64 bit echo is used or this patch is
                        # applied, then the full address space of $pid is
                        # migrated.

To check memory migration, I watched:
  grep MemUsed /sys/devices/system/node/node*/meminfo

Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: compaction: defer compaction using an exponential backoff when compaction fails
Mel Gorman [Mon, 24 May 2010 21:32:32 +0000]
mm: compaction: defer compaction using an exponential backoff when compaction fails

The fragmentation index may indicate that a failure is due to external
fragmentation but after a compaction run completes, it is still possible
for an allocation to fail.  There are two obvious reasons as to why

  o Page migration cannot move all pages so fragmentation remains
  o A suitable page may exist but watermarks are not met

In the event of compaction followed by an allocation failure, this patch
defers further compaction in the zone (1 << compact_defer_shift) times.
If the next compaction attempt also fails, compact_defer_shift is
increased up to a maximum of 6.  If compaction succeeds, the defer
counters are reset again.

The zone that is deferred is the first zone in the zonelist - i.e.  the
preferred zone.  To defer compaction in the other zones, the information
would need to be stored in the zonelist or implemented similar to the
zonelist_cache.  This would impact the fast-paths and is not justified at
this time.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: compaction: add a tunable that decides when memory should be compacted and when...
Mel Gorman [Mon, 24 May 2010 21:32:31 +0000]
mm: compaction: add a tunable that decides when memory should be compacted and when it should be reclaimed

The kernel applies some heuristics when deciding if memory should be
compacted or reclaimed to satisfy a high-order allocation.  One of these
is based on the fragmentation.  If the index is below 500, memory will not
be compacted.  This choice is arbitrary and not based on data.  To help
optimise the system and set a sensible default for this value, this patch
adds a sysctl extfrag_threshold.  The kernel will only compact memory if
the fragmentation index is above the extfrag_threshold.

[randy.dunlap@oracle.com: Fix build errors when proc fs is not configured]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: compaction: direct compact when a high-order allocation fails
Mel Gorman [Mon, 24 May 2010 21:32:30 +0000]
mm: compaction: direct compact when a high-order allocation fails

Ordinarily when a high-order allocation fails, direct reclaim is entered
to free pages to satisfy the allocation.  With this patch, it is
determined if an allocation failed due to external fragmentation instead
of low memory and if so, the calling process will compact until a suitable
page is freed.  Compaction by moving pages in memory is considerably
cheaper than paging out to disk and works where there are locked pages or
no swap.  If compaction fails to free a page of a suitable size, then
reclaim will still occur.

Direct compaction returns as soon as possible.  As each block is
compacted, it is checked if a suitable page has been freed and if so, it
returns.

[akpm@linux-foundation.org: Fix build errors]
[aarcange@redhat.com: fix count_vm_event preempt in memory compaction direct reclaim]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: compaction: add /sys trigger for per-node memory compaction
Mel Gorman [Mon, 24 May 2010 21:32:29 +0000]
mm: compaction: add /sys trigger for per-node memory compaction

Add a per-node sysfs file called compact.  When the file is written to,
each zone in that node is compacted.  The intention that this would be
used by something like a job scheduler in a batch system before a job
starts so that the job can allocate the maximum number of hugepages
without significant start-up cost.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: compaction: add /proc trigger for memory compaction
Mel Gorman [Mon, 24 May 2010 21:32:28 +0000]
mm: compaction: add /proc trigger for memory compaction

Add a proc file /proc/sys/vm/compact_memory.  When an arbitrary value is
written to the file, all zones are compacted.  The expected user of such a
trigger is a job scheduler that prepares the system before the target
application runs.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: compaction: memory compaction core
Mel Gorman [Mon, 24 May 2010 21:32:27 +0000]
mm: compaction: memory compaction core

This patch is the core of a mechanism which compacts memory in a zone by
relocating movable pages towards the end of the zone.

A single compaction run involves a migration scanner and a free scanner.
Both scanners operate on pageblock-sized areas in the zone.  The migration
scanner starts at the bottom of the zone and searches for all movable
pages within each area, isolating them onto a private list called
migratelist.  The free scanner starts at the top of the zone and searches
for suitable areas and consumes the free pages within making them
available for the migration scanner.  The pages isolated for migration are
then migrated to the newly isolated free pages.

[aarcange@redhat.com: Fix unsafe optimisation]
[mel@csn.ul.ie: do not schedule work on other CPUs for compaction]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: move definition for LRU isolation modes to a header
Mel Gorman [Mon, 24 May 2010 21:32:26 +0000]
mm: move definition for LRU isolation modes to a header

Currently, vmscan.c defines the isolation modes for __isolate_lru_page().
Memory compaction needs access to these modes for isolating pages for
migration.  This patch exports them.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: export fragmentation index via debugfs
Mel Gorman [Mon, 24 May 2010 21:32:26 +0000]
mm: export fragmentation index via debugfs

The fragmentation fragmentation index, is only meaningful if an allocation
would fail and indicates what the failure is due to.  A value of -1 such
as in many of the examples above states that the allocation would succeed.
 If it would fail, the value is between 0 and 1.  A value tending towards
0 implies the allocation failed due to a lack of memory.  A value tending
towards 1 implies it failed due to external fragmentation.

For the most part, the huge page size will be the size of interest but not
necessarily so it is exported on a per-order and per-zo basis via
/sys/kernel/debug/extfrag/extfrag_index

> cat /sys/kernel/debug/extfrag/extfrag_index
Node 0, zone      DMA -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.00
Node 0, zone   Normal -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 0.954

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: export unusable free space index via debugfs
Mel Gorman [Mon, 24 May 2010 21:32:25 +0000]
mm: export unusable free space index via debugfs

The unusable free space index measures how much of the available free
memory cannot be used to satisfy an allocation of a given size and is a
value between 0 and 1.  The higher the value, the more of free memory is
unusable and by implication, the worse the external fragmentation is.  For
the most part, the huge page size will be the size of interest but not
necessarily so it is exported on a per-order and per-zone basis via
/sys/kernel/debug/extfrag/unusable_index.

> cat /sys/kernel/debug/extfrag/unusable_index
Node 0, zone      DMA 0.000 0.000 0.000 0.001 0.005 0.013 0.021 0.037 0.037 0.101 0.230
Node 0, zone   Normal 0.000 0.000 0.000 0.001 0.002 0.002 0.005 0.015 0.028 0.028 0.054

[akpm@linux-foundation.org: Fix allnoconfig]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: migration: avoid race between shift_arg_pages() and rmap_walk() during migration...
Mel Gorman [Mon, 24 May 2010 21:32:24 +0000]
mm: migration: avoid race between shift_arg_pages() and rmap_walk() during migration by not migrating temporary stacks

Page migration requires rmap to be able to find all ptes mapping a page
at all times, otherwise the migration entry can be instantiated, but it
is possible to leave one behind if the second rmap_walk fails to find
the page.  If this page is later faulted, migration_entry_to_page() will
call BUG because the page is locked indicating the page was migrated by
the migration PTE not cleaned up. For example

  kernel BUG at include/linux/swapops.h:105!
  invalid opcode: 0000 [#1] PREEMPT SMP
  ...
  Call Trace:
   [<ffffffff810e951a>] handle_mm_fault+0x3f8/0x76a
   [<ffffffff8130c7a2>] do_page_fault+0x44a/0x46e
   [<ffffffff813099b5>] page_fault+0x25/0x30
   [<ffffffff8114de33>] load_elf_binary+0x152a/0x192b
   [<ffffffff8111329b>] search_binary_handler+0x173/0x313
   [<ffffffff81114896>] do_execve+0x219/0x30a
   [<ffffffff8100a5c6>] sys_execve+0x43/0x5e
   [<ffffffff8100320a>] stub_execve+0x6a/0xc0
  RIP  [<ffffffff811094ff>] migration_entry_wait+0xc1/0x129

There is a race between shift_arg_pages and migration that triggers this
bug.  A temporary stack is setup during exec and later moved.  If
migration moves a page in the temporary stack and the VMA is then removed
before migration completes, the migration PTE may not be found leading to
a BUG when the stack is faulted.

This patch causes pages within the temporary stack during exec to be
skipped by migration.  It does this by marking the VMA covering the
temporary stack with an otherwise impossible combination of VMA flags.
These flags are cleared when the temporary stack is moved to its final
location.

[kamezawa.hiroyu@jp.fujitsu.com: idea for having migration skip temporary stacks]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove
Mel Gorman [Mon, 24 May 2010 21:32:21 +0000]
mm: allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove

CONFIG_MIGRATION currently depends on CONFIG_NUMA or on the architecture
being able to hot-remove memory.  The main users of page migration such as
sys_move_pages(), sys_migrate_pages() and cpuset process migration are
only beneficial on NUMA so it makes sense.

As memory compaction will operate within a zone and is useful on both NUMA
and non-NUMA systems, this patch allows CONFIG_MIGRATION to be set if the
user selects CONFIG_COMPACTION as an option.

[akpm@linux-foundation.org: Depend on CONFIG_HUGETLB_PAGE]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: migration: allow the migration of PageSwapCache pages
Mel Gorman [Mon, 24 May 2010 21:32:20 +0000]
mm: migration: allow the migration of PageSwapCache pages

PageAnon pages that are unmapped may or may not have an anon_vma so are
not currently migrated.  However, a swap cache page can be migrated and
fits this description.  This patch identifies page swap caches and allows
them to be migrated but ensures that no attempt to made to remap the pages
would would potentially try to access an already freed anon_vma.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: migration: do not try to migrate unmapped anonymous pages
Mel Gorman [Mon, 24 May 2010 21:32:19 +0000]
mm: migration: do not try to migrate unmapped anonymous pages

rmap_walk_anon() was triggering errors in memory compaction that look like
use-after-free errors.  The problem is that between the page being
isolated from the LRU and rcu_read_lock() being taken, the mapcount of the
page dropped to 0 and the anon_vma gets freed.  This can happen during
memory compaction if pages being migrated belong to a process that exits
before migration completes.  Hence, the use-after-free race looks like

 1. Page isolated for migration
 2. Process exits
 3. page_mapcount(page) drops to zero so anon_vma was no longer reliable
 4. unmap_and_move() takes the rcu_lock but the anon_vma is already garbage
 4. call try_to_unmap, looks up tha anon_vma and "locks" it but the lock
    is garbage.

This patch checks the mapcount after the rcu lock is taken.  If the
mapcount is zero, the anon_vma is assumed to be freed and no further
action is taken.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: migration: share the anon_vma ref counts between KSM and page migration
Mel Gorman [Mon, 24 May 2010 21:32:18 +0000]
mm: migration: share the anon_vma ref counts between KSM and page migration

For clarity of review, KSM and page migration have separate refcounts on
the anon_vma.  While clear, this is a waste of memory.  This patch gets
KSM and page migration to share their toys in a spirit of harmony.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: migration: take a reference to the anon_vma before migrating
Mel Gorman [Mon, 24 May 2010 21:32:17 +0000]
mm: migration: take a reference to the anon_vma before migrating

This patchset is a memory compaction mechanism that reduces external
fragmentation memory by moving GFP_MOVABLE pages to a fewer number of
pageblocks.  The term "compaction" was chosen as there are is a number of
mechanisms that are not mutually exclusive that can be used to defragment
memory.  For example, lumpy reclaim is a form of defragmentation as was
slub "defragmentation" (really a form of targeted reclaim).  Hence, this
is called "compaction" to distinguish it from other forms of
defragmentation.

In this implementation, a full compaction run involves two scanners
operating within a zone - a migration and a free scanner.  The migration
scanner starts at the beginning of a zone and finds all movable pages
within one pageblock_nr_pages-sized area and isolates them on a
migratepages list.  The free scanner begins at the end of the zone and
searches on a per-area basis for enough free pages to migrate all the
pages on the migratepages list.  As each area is respectively migrated or
exhausted of free pages, the scanners are advanced one area.  A compaction
run completes within a zone when the two scanners meet.

This method is a bit primitive but is easy to understand and greater
sophistication would require maintenance of counters on a per-pageblock
basis.  This would have a big impact on allocator fast-paths to improve
compaction which is a poor trade-off.

It also does not try relocate virtually contiguous pages to be physically
contiguous.  However, assuming transparent hugepages were in use, a
hypothetical khugepaged might reuse compaction code to isolate free pages,
split them and relocate userspace pages for promotion.

Memory compaction can be triggered in one of three ways.  It may be
triggered explicitly by writing any value to /proc/sys/vm/compact_memory
and compacting all of memory.  It can be triggered on a per-node basis by
writing any value to /sys/devices/system/node/nodeN/compact where N is the
node ID to be compacted.  When a process fails to allocate a high-order
page, it may compact memory in an attempt to satisfy the allocation
instead of entering direct reclaim.  Explicit compaction does not finish
until the two scanners meet and direct compaction ends if a suitable page
becomes available that would meet watermarks.

The series is in 14 patches.  The first three are not "core" to the series
but are important pre-requisites.

Patch 1 reference counts anon_vma for rmap_walk_anon(). Without this
patch, it's possible to use anon_vma after free if the caller is
not holding a VMA or mmap_sem for the pages in question. While
there should be no existing user that causes this problem,
it's a requirement for memory compaction to be stable. The patch
is at the start of the series for bisection reasons.
Patch 2 merges the KSM and migrate counts. It could be merged with patch 1
but would be slightly harder to review.
Patch 3 skips over unmapped anon pages during migration as there are no
guarantees about the anon_vma existing. There is a window between
when a page was isolated and migration started during which anon_vma
could disappear.
Patch 4 notes that PageSwapCache pages can still be migrated even if they
are unmapped.
Patch 5 allows CONFIG_MIGRATION to be set without CONFIG_NUMA
Patch 6 exports a "unusable free space index" via debugfs. It's
a measure of external fragmentation that takes the size of the
allocation request into account. It can also be calculated from
userspace so can be dropped if requested
Patch 7 exports a "fragmentation index" which only has meaning when an
allocation request fails. It determines if an allocation failure
would be due to a lack of memory or external fragmentation.
Patch 8 moves the definition for LRU isolation modes for use by compaction
Patch 9 is the compaction mechanism although it's unreachable at this point
Patch 10 adds a means of compacting all of memory with a proc trgger
Patch 11 adds a means of compacting a specific node with a sysfs trigger
Patch 12 adds "direct compaction" before "direct reclaim" if it is
determined there is a good chance of success.
Patch 13 adds a sysctl that allows tuning of the threshold at which the
kernel will compact or direct reclaim
Patch 14 temporarily disables compaction if an allocation failure occurs
after compaction.

Testing of compaction was in three stages.  For the test, debugging,
preempt, the sleep watchdog and lockdep were all enabled but nothing nasty
popped out.  min_free_kbytes was tuned as recommended by hugeadm to help
fragmentation avoidance and high-order allocations.  It was tested on X86,
X86-64 and PPC64.

Ths first test represents one of the easiest cases that can be faced for
lumpy reclaim or memory compaction.

1. Machine freshly booted and configured for hugepage usage with
a) hugeadm --create-global-mounts
b) hugeadm --pool-pages-max DEFAULT:8G
c) hugeadm --set-recommended-min_free_kbytes
d) hugeadm --set-recommended-shmmax

The min_free_kbytes here is important. Anti-fragmentation works best
when pageblocks don't mix. hugeadm knows how to calculate a value that
will significantly reduce the worst of external-fragmentation-related
events as reported by the mm_page_alloc_extfrag tracepoint.

2. Load up memory
a) Start updatedb
b) Create in parallel a X files of pagesize*128 in size. Wait
   until files are created. By parallel, I mean that 4096 instances
   of dd were launched, one after the other using &. The crude
   objective being to mix filesystem metadata allocations with
   the buffer cache.
c) Delete every second file so that pageblocks are likely to
   have holes
d) kill updatedb if it's still running

At this point, the system is quiet, memory is full but it's full with
clean filesystem metadata and clean buffer cache that is unmapped.
This is readily migrated or discarded so you'd expect lumpy reclaim
to have no significant advantage over compaction but this is at
the POC stage.

3. In increments, attempt to allocate 5% of memory as hugepages.
   Measure how long it took, how successful it was, how many
   direct reclaims took place and how how many compactions. Note
   the compaction figures might not fully add up as compactions
   can take place for orders other than the hugepage size

X86 vanilla compaction
Final page count                    913                916 (attempted 1002)
pages reclaimed                   68296               9791

X86-64 vanilla compaction
Final page count:                   901                902 (attempted 1002)
Total pages reclaimed:           112599              53234

PPC64 vanilla compaction
Final page count:                    93                 94 (attempted 110)
Total pages reclaimed:           103216              61838

There was not a dramatic improvement in success rates but it wouldn't be
expected in this case either.  What was important is that fewer pages were
reclaimed in all cases reducing the amount of IO required to satisfy a
huge page allocation.

The second tests were all performance related - kernbench, netperf, iozone
and sysbench.  None showed anything too remarkable.

The last test was a high-order allocation stress test.  Many kernel
compiles are started to fill memory with a pressured mix of unmovable and
movable allocations.  During this, an attempt is made to allocate 90% of
memory as huge pages - one at a time with small delays between attempts to
avoid flooding the IO queue.

                                             vanilla   compaction
Percentage of request allocated X86               98           99
Percentage of request allocated X86-64            95           98
Percentage of request allocated PPC64             55           70

This patch:

rmap_walk_anon() does not use page_lock_anon_vma() for looking up and
locking an anon_vma and it does not appear to have sufficient locking to
ensure the anon_vma does not disappear from under it.

This patch copies an approach used by KSM to take a reference on the
anon_vma while pages are being migrated.  This should prevent rmap_walk()
running into nasty surprises later because anon_vma has been freed.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: default to node zonelist ordering when nodes have only lowmem
David Rientjes [Mon, 24 May 2010 21:32:13 +0000]
mm: default to node zonelist ordering when nodes have only lowmem

There are two types of zonelist ordering methodologies:

 - node order, preferring allocations on a node to stay local to and

 - zone order, preferring allocations come from a higher zone to avoid
   allocating in lowmem zones even though they may not be local.

The ordering technique used by the kernel is configurable on the command
line, but also has some logic to determine what the default should be.

This logic currently lacks knowledge of systems where a node may only have
lowmem.  For such systems, it is necessary to use node order so that
GFP_KERNEL allocations may be satisfied by nodes consisting of only
lowmem.

If zone order is used, GFP_KERNEL allocations to such nodes are actually
allocated on a node with local affinity that includes ZONE_NORMAL.

This change defaults to node zonelist ordering if any node lacks
ZONE_NORMAL.

To force zone order, append 'numa_zonelist_order=zone' to the kernel
command line.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agopagemap: add #ifdefs CONFIG_HUGETLB_PAGE on code walking hugetlb vma
Naoya Horiguchi [Mon, 24 May 2010 21:32:12 +0000]
pagemap: add #ifdefs CONFIG_HUGETLB_PAGE on code walking hugetlb vma

If !CONFIG_HUGETLB_PAGE, pagemap_hugetlb_range() is never called.  So put
it (and its calling function) into #ifdef block.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomincore: do nested page table walks
Johannes Weiner [Mon, 24 May 2010 21:32:11 +0000]
mincore: do nested page table walks

Do page table walks with the well-known nested loops we use in several
other places already.

This avoids doing full page table walks after every pte range and also
allows to handle unmapped areas bigger than one pte range in one go.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomincore: pass ranges as start,end address pairs
Johannes Weiner [Mon, 24 May 2010 21:32:11 +0000]
mincore: pass ranges as start,end address pairs

Instead of passing a start address and a number of pages into the helper
functions, convert them to use a start and an end address.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomincore: break do_mincore() into logical pieces
Johannes Weiner [Mon, 24 May 2010 21:32:10 +0000]
mincore: break do_mincore() into logical pieces

Split out functions to handle hugetlb ranges, pte ranges and unmapped
ranges, to improve readability but also to prepare the file structure for
nested page table walks.

No semantic changes intended.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomincore: cleanups
Johannes Weiner [Mon, 24 May 2010 21:32:09 +0000]
mincore: cleanups

This fixes some minor issues that bugged me while going over the code:

o adjust argument order of do_mincore() to match the syscall
o simplify range length calculation
o drop superfluous shift in huge tlb calculation, address is page aligned
o drop dead nr_huge calculation
o check pte_none() before pte_present()
o comment and whitespace fixes

No semantic changes intended.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agocpuset,mm: fix no node to alloc memory when changing cpuset's mems
Miao Xie [Mon, 24 May 2010 21:32:08 +0000]
cpuset,mm: fix no node to alloc memory when changing cpuset's mems

Before applying this patch, cpuset updates task->mems_allowed and
mempolicy by setting all new bits in the nodemask first, and clearing all
old unallowed bits later.  But in the way, the allocator may find that
there is no node to alloc memory.

The reason is that cpuset rebinds the task's mempolicy, it cleans the
nodes which the allocater can alloc pages on, for example:

(mpol: mempolicy)
task1 task1's mpol task2
alloc page 1
  alloc on node0? NO 1
1 change mems from 1 to 0
1 rebind task1's mpol
0-1   set new bits
0      clear disallowed bits
  alloc on node1? NO 0
  ...
can't alloc page
  goto oom

This patch fixes this problem by expanding the nodes range first(set newly
allowed bits) and shrink it lazily(clear newly disallowed bits).  So we
use a variable to tell the write-side task that read-side task is reading
nodemask, and the write-side task clears newly disallowed nodes after
read-side task ends the current memory allocation.

[akpm@linux-foundation.org: fix spello]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomempolicy: restructure rebinding-mempolicy functions
Miao Xie [Mon, 24 May 2010 21:32:07 +0000]
mempolicy: restructure rebinding-mempolicy functions

Nick Piggin reported that the allocator may see an empty nodemask when
changing cpuset's mems[1].  It happens only on the kernel that do not do
atomic nodemask_t stores.  (MAX_NUMNODES > BITS_PER_LONG)

But I found that there is also a problem on the kernel that can do atomic
nodemask_t stores.  The problem is that the allocator can't find a node to
alloc page when changing cpuset's mems though there is a lot of free
memory.  The reason is like this:

(mpol: mempolicy)
task1 task1's mpol task2
alloc page 1
  alloc on node0? NO 1
1 change mems from 1 to 0
1 rebind task1's mpol
0-1   set new bits
0      clear disallowed bits
  alloc on node1? NO 0
  ...
can't alloc page
  goto oom

I can use the attached program reproduce it by the following step:

# mkdir /dev/cpuset
# mount -t cpuset cpuset /dev/cpuset
# mkdir /dev/cpuset/1
# echo `cat /dev/cpuset/cpus` > /dev/cpuset/1/cpus
# echo `cat /dev/cpuset/mems` > /dev/cpuset/1/mems
# echo $$ > /dev/cpuset/1/tasks
# numactl --membind=`cat /dev/cpuset/mems` ./cpuset_mem_hog <nr_tasks> &
   <nr_tasks> = max(nr_cpus - 1, 1)
# killall -s SIGUSR1 cpuset_mem_hog
# ./change_mems.sh

several hours later, oom will happen though there is a lot of free memory.

This patchset fixes this problem by expanding the nodes range first(set
newly allowed bits) and shrink it lazily(clear newly disallowed bits).  So
we use a variable to tell the write-side task that read-side task is
reading nodemask, and the write-side task clears newly disallowed nodes
after read-side task ends the current memory allocation.

This patch:

In order to fix no node to alloc memory, when we want to update mempolicy
and mems_allowed, we expand the set of nodes first (set all the newly
nodes) and shrink the set of nodes lazily(clean disallowed nodes), But the
mempolicy's rebind functions may breaks the expanding.

So we restructure the mempolicy's rebind functions and split the rebind
work to two steps, just like the update of cpuset's mems: The 1st step:
expand the set of the mempolicy's nodes.  The 2nd step: shrink the set of
the mempolicy's nodes.  It is used when there is no real lock to protect
the mempolicy in the read-side.  Otherwise we can do rebind work at once.

In order to implement it, we define

enum mpol_rebind_step {
MPOL_REBIND_ONCE,
MPOL_REBIND_STEP1,
MPOL_REBIND_STEP2,
MPOL_REBIND_NSTEP,
};

If the mempolicy needn't be updated by two steps, we can pass
MPOL_REBIND_ONCE to the rebind functions.  Or we can pass
MPOL_REBIND_STEP1 to do the first step of the rebind work and pass
MPOL_REBIND_STEP2 to do the second step work.

Besides that, it maybe long time between these two step and we have to
release the lock that protects mempolicy and mems_allowed.  If we hold the
lock once again, we must check whether the current mempolicy is under the
rebinding (the first step has been done) or not, because the task may
alloc a new mempolicy when we don't hold the lock.  So we defined the
following flag to identify it:

#define MPOL_F_REBINDING (1 << 2)

The new functions will be used in the next patch.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomempolicy: document cpuset interaction with tmpfs mpol mount option
Lee Schermerhorn [Mon, 24 May 2010 21:32:05 +0000]
mempolicy: document cpuset interaction with tmpfs mpol mount option

Update Documentation/filesystems/tmpfs.txt to describe the interaction of
tmpfs mount option memory policy with tasks' cpuset mems_allowed.

Note: the mount(8) man page [in the util-linux-ng package] requires
similiar updates.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomempolicy: factor mpol_shared_policy_init() return paths
Lee Schermerhorn [Mon, 24 May 2010 21:32:04 +0000]
mempolicy: factor mpol_shared_policy_init() return paths

Factor out duplicate put/frees in mpol_shared_policy_init() to a common
return path.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomempolicy: rename policy_types and cleanup initialization
Lee Schermerhorn [Mon, 24 May 2010 21:32:04 +0000]
mempolicy: rename policy_types and cleanup initialization

Rename 'policy_types[]' to 'policy_modes[]' to better match the array
contents.

Use designated intializer syntax for policy_modes[].

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomempolicy: lose unnecessary loop variable in mpol_parse_str()
Lee Schermerhorn [Mon, 24 May 2010 21:32:03 +0000]
mempolicy: lose unnecessary loop variable in mpol_parse_str()

We don't really need the extra variable 'i' in mpol_parse_str().  The only
use is as the the loop variable.  Then, it's assigned to 'mode'.  Just use
mode, and loose the 'uninitialized_var()' macro.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomempolicy: don't call mpol_set_nodemask() when no_context
Lee Schermerhorn [Mon, 24 May 2010 21:32:02 +0000]
mempolicy: don't call mpol_set_nodemask() when no_context

No need to call mpol_set_nodemask() when we have no context for the
mempolicy.  This can occur when we're parsing a tmpfs 'mpol' mount option.
 Just save the raw nodemask in the mempolicy's w.user_nodemask member for
use when a tmpfs/shmem file is created.  mpol_shared_policy_init() will
"contextualize" the policy for the new file based on the creating task's
context.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomempolicy: remove redundant check
Bob Liu [Mon, 24 May 2010 21:32:01 +0000]
mempolicy: remove redundant check

Lee's patch "mempolicy: use MPOL_PREFERRED for system-wide default policy"
has made the MPOL_DEFAULT only used in the memory policy APIs.  So, no
need to check in __mpol_equal also.  Also get rid of mpol_match_intent()
and move its logic directly into __mpol_equal().

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomempolicy: remove case MPOL_INTERLEAVE from policy_zonelist()
Bob Liu [Mon, 24 May 2010 21:32:00 +0000]
mempolicy: remove case MPOL_INTERLEAVE from policy_zonelist()

In policy_zonelist() mode MPOL_INTERLEAVE shouldn't happen, so fall
through to BUG() instead of break to return.  I also fixed the comment.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomempolicy: remove redundant code
Bob Liu [Mon, 24 May 2010 21:31:59 +0000]
mempolicy: remove redundant code

1.  In funtion is_valid_nodemask(), varibable k will be inited to 0 in
   the following loop, needn't init to policy_zone anymore.

2. (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES) has already defined
   to MPOL_MODE_FLAGS in mempolicy.h.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agomm: remove return value of putback_lru_pages()
Minchan Kim [Mon, 24 May 2010 21:31:59 +0000]
mm: remove return value of putback_lru_pages()

putback_lru_page() never can fail.  So it doesn't matter count of "the
number of pages put back".

In addition, users of this functions don't use return value.

Let's remove unnecessary code.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoshmem: remove redundant code
Huang Shijie [Mon, 24 May 2010 21:31:58 +0000]
shmem: remove redundant code

prep_new_page() will call set_page_private(page, 0) to initialise the
page, so the code is redundant.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agosparsemem: on no vmemmap path put mem_map on node high too
Yinghai Lu [Mon, 24 May 2010 21:31:57 +0000]
sparsemem: on no vmemmap path put mem_map on node high too

We need to put mem_map high when virtual memmap is not used.

before this patch
free mem pfn range on first node:
[    0.000000]  19 - 1f
[    0.000000]  28 40 - 80 95
[    0.000000]  702 740 - 1000 1000
[    0.000000]  347c - 347e
[    0.000000]  34e7 3500 - 3b80 3b8b
[    0.000000]  73b8b 73bc0 - 73c00 73c00
[    0.000000]  73ddd - 73e00
[    0.000000]  73fdd - 74000
[    0.000000]  741dd - 74200
[    0.000000]  743dd - 74400
[    0.000000]  745dd - 74600
[    0.000000]  747dd - 74800
[    0.000000]  749dd - 74a00
[    0.000000]  74bdd - 74c00
[    0.000000]  74ddd - 74e00
[    0.000000]  74fdd - 75000
[    0.000000]  751dd - 75200
[    0.000000]  753dd - 75400
[    0.000000]  755dd - 75600
[    0.000000]  757dd - 75800
[    0.000000]  759dd - 75a00
[    0.000000]  79bdd 79c00 - 7d540 7d550
[    0.000000]  7f745 - 7f750
[    0.000000]  10000b 100040 - 2080000 2080000
so only 79c00 - 7d540 are major free block under 4g...

after this patch, we will get
[    0.000000]  19 - 1f
[    0.000000]  28 40 - 80 95
[    0.000000]  702 740 - 1000 1000
[    0.000000]  347c - 347e
[    0.000000]  34e7 3500 - 3600 3600
[    0.000000]  37dd - 3800
[    0.000000]  39dd - 3a00
[    0.000000]  3bdd - 3c00
[    0.000000]  3ddd - 3e00
[    0.000000]  3fdd - 4000
[    0.000000]  41dd - 4200
[    0.000000]  43dd - 4400
[    0.000000]  45dd - 4600
[    0.000000]  47dd - 4800
[    0.000000]  49dd - 4a00
[    0.000000]  4bdd - 4c00
[    0.000000]  4ddd - 4e00
[    0.000000]  4fdd - 5000
[    0.000000]  51dd - 5200
[    0.000000]  53dd - 5400
[    0.000000]  95dd 9600 - 7d540 7d550
[    0.000000]  7f745 - 7f750
[    0.000000]  17000b 170040 - 2080000 2080000
we will have 9600 - 7d540 for major free block...

sparse-vmemmap path already used __alloc_bootmem_node_high()

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agopage allocator: reduce fragmentation in buddy allocator by adding buddies that are...
Corrado Zoccolo [Mon, 24 May 2010 21:31:54 +0000]
page allocator: reduce fragmentation in buddy allocator by adding buddies that are merging to the tail of the free lists

In order to reduce fragmentation, this patch classifies freed pages in two
groups according to their probability of being part of a high order merge.
 Pages belonging to a compound whose next-highest buddy is free are more
likely to be part of a high order merge in the near future, so they will
be added at the tail of the freelist.  The remaining pages are put at the
front of the freelist.

In this way, the pages that are more likely to cause a big merge are kept
free longer.  Consequently there is a tendency to aggregate the
long-living allocations on a subset of the compounds, reducing the
fragmentation.

This heuristic was tested on three machines, x86, x86-64 and ppc64 with
3GB of RAM in each machine.  The tests were kernbench, netperf, sysbench
and STREAM for performance and a high-order stress test for huge page
allocations.

KernBench X86
Elapsed mean     374.77 ( 0.00%)   375.10 (-0.09%)
User    mean     649.53 ( 0.00%)   650.44 (-0.14%)
System  mean      54.75 ( 0.00%)    54.18 ( 1.05%)
CPU     mean     187.75 ( 0.00%)   187.25 ( 0.27%)

KernBench X86-64
Elapsed mean      94.45 ( 0.00%)    94.01 ( 0.47%)
User    mean     323.27 ( 0.00%)   322.66 ( 0.19%)
System  mean      36.71 ( 0.00%)    36.50 ( 0.57%)
CPU     mean     380.75 ( 0.00%)   381.75 (-0.26%)

KernBench PPC64
Elapsed mean     173.45 ( 0.00%)   173.74 (-0.17%)
User    mean     587.99 ( 0.00%)   587.95 ( 0.01%)
System  mean      60.60 ( 0.00%)    60.57 ( 0.05%)
CPU     mean     373.50 ( 0.00%)   372.75 ( 0.20%)

Nothing notable for kernbench.

NetPerf UDP X86
      64    42.68 ( 0.00%)     42.77 ( 0.21%)
     128    85.62 ( 0.00%)     85.32 (-0.35%)
     256   170.01 ( 0.00%)    168.76 (-0.74%)
    1024   655.68 ( 0.00%)    652.33 (-0.51%)
    2048  1262.39 ( 0.00%)   1248.61 (-1.10%)
    3312  1958.41 ( 0.00%)   1944.61 (-0.71%)
    4096  2345.63 ( 0.00%)   2318.83 (-1.16%)
    8192  4132.90 ( 0.00%)   4089.50 (-1.06%)
   16384  6770.88 ( 0.00%)   6642.05 (-1.94%)*

NetPerf UDP X86-64
      64   148.82 ( 0.00%)    154.92 ( 3.94%)
     128   298.96 ( 0.00%)    312.95 ( 4.47%)
     256   583.67 ( 0.00%)    626.39 ( 6.82%)
    1024  2293.18 ( 0.00%)   2371.10 ( 3.29%)
    2048  4274.16 ( 0.00%)   4396.83 ( 2.79%)
    3312  6356.94 ( 0.00%)   6571.35 ( 3.26%)
    4096  7422.68 ( 0.00%)   7635.42 ( 2.79%)*
    8192 12114.81 ( 0.00%)* 12346.88 ( 1.88%)
   16384 17022.28 ( 0.00%)* 17033.19 ( 0.06%)*
             1.64%             2.73%

NetPerf UDP PPC64
      64    49.98 ( 0.00%)     50.25 ( 0.54%)
     128    98.66 ( 0.00%)    100.95 ( 2.27%)
     256   197.33 ( 0.00%)    191.03 (-3.30%)
    1024   761.98 ( 0.00%)    785.07 ( 2.94%)
    2048  1493.50 ( 0.00%)   1510.85 ( 1.15%)
    3312  2303.95 ( 0.00%)   2271.72 (-1.42%)
    4096  2774.56 ( 0.00%)   2773.06 (-0.05%)
    8192  4918.31 ( 0.00%)   4793.59 (-2.60%)
   16384  7497.98 ( 0.00%)   7749.52 ( 3.25%)

The tests are run to have confidence limits within 1%.  Results marked
with a * were not confident although in this case, it's only outside by
small amounts.  Even with some results that were not confident, the
netperf UDP results were generally positive.

NetPerf TCP X86
      64   652.25 ( 0.00%)*   648.12 (-0.64%)*
            23.80%            22.82%
     128  1229.98 ( 0.00%)*  1220.56 (-0.77%)*
            21.03%            18.90%
     256  2105.88 ( 0.00%)   1872.03 (-12.49%)*
             1.00%            16.46%
    1024  3476.46 ( 0.00%)*  3548.28 ( 2.02%)*
            13.37%            11.39%
    2048  4023.44 ( 0.00%)*  4231.45 ( 4.92%)*
             9.76%            12.48%
    3312  4348.88 ( 0.00%)*  4396.96 ( 1.09%)*
             6.49%             8.75%
    4096  4726.56 ( 0.00%)*  4877.71 ( 3.10%)*
             9.85%             8.50%
    8192  4732.28 ( 0.00%)*  5777.77 (18.10%)*
             9.13%            13.04%
   16384  5543.05 ( 0.00%)*  5906.24 ( 6.15%)*
             7.73%             8.68%

NETPERF TCP X86-64
            netperf-tcp-vanilla-netperf       netperf-tcp
                   tcp-vanilla     pgalloc-delay
      64  1895.87 ( 0.00%)*  1775.07 (-6.81%)*
             5.79%             4.78%
     128  3571.03 ( 0.00%)*  3342.20 (-6.85%)*
             3.68%             6.06%
     256  5097.21 ( 0.00%)*  4859.43 (-4.89%)*
             3.02%             2.10%
    1024  8919.10 ( 0.00%)*  8892.49 (-0.30%)*
             5.89%             6.55%
    2048 10255.46 ( 0.00%)* 10449.39 ( 1.86%)*
             7.08%             7.44%
    3312 10839.90 ( 0.00%)* 10740.15 (-0.93%)*
             6.87%             7.33%
    4096 10814.84 ( 0.00%)* 10766.97 (-0.44%)*
             6.86%             8.18%
    8192 11606.89 ( 0.00%)* 11189.28 (-3.73%)*
             7.49%             5.55%
   16384 12554.88 ( 0.00%)* 12361.22 (-1.57%)*
             7.36%             6.49%

NETPERF TCP PPC64
            netperf-tcp-vanilla-netperf       netperf-tcp
                   tcp-vanilla     pgalloc-delay
      64   594.17 ( 0.00%)    596.04 ( 0.31%)*
             1.00%             2.29%
     128  1064.87 ( 0.00%)*  1074.77 ( 0.92%)*
             1.30%             1.40%
     256  1852.46 ( 0.00%)*  1856.95 ( 0.24%)
             1.25%             1.00%
    1024  3839.46 ( 0.00%)*  3813.05 (-0.69%)
             1.02%             1.00%
    2048  4885.04 ( 0.00%)*  4881.97 (-0.06%)*
             1.15%             1.04%
    3312  5506.90 ( 0.00%)   5459.72 (-0.86%)
    4096  6449.19 ( 0.00%)   6345.46 (-1.63%)
    8192  7501.17 ( 0.00%)   7508.79 ( 0.10%)
   16384  9618.65 ( 0.00%)   9490.10 (-1.35%)

There was a distinct lack of confidence in the X86* figures so I included
what the devation was where the results were not confident.  Many of the
results, whether gains or losses were within the standard deviation so no
solid conclusion can be reached on performance impact.  Looking at the
figures, only the X86-64 ones look suspicious with a few losses that were
outside the noise.  However, the results were so unstable that without
knowing why they vary so much, a solid conclusion cannot be reached.

SYSBENCH X86
              sysbench-vanilla     pgalloc-delay
           1  7722.85 ( 0.00%)  7756.79 ( 0.44%)
           2 14901.11 ( 0.00%) 13683.44 (-8.90%)
           3 15171.71 ( 0.00%) 14888.25 (-1.90%)
           4 14966.98 ( 0.00%) 15029.67 ( 0.42%)
           5 14370.47 ( 0.00%) 14865.00 ( 3.33%)
           6 14870.33 ( 0.00%) 14845.57 (-0.17%)
           7 14429.45 ( 0.00%) 14520.85 ( 0.63%)
           8 14354.35 ( 0.00%) 14362.31 ( 0.06%)

SYSBENCH X86-64
           1 17448.70 ( 0.00%) 17484.41 ( 0.20%)
           2 34276.39 ( 0.00%) 34251.00 (-0.07%)
           3 50805.25 ( 0.00%) 50854.80 ( 0.10%)
           4 66667.10 ( 0.00%) 66174.69 (-0.74%)
           5 66003.91 ( 0.00%) 65685.25 (-0.49%)
           6 64981.90 ( 0.00%) 65125.60 ( 0.22%)
           7 64933.16 ( 0.00%) 64379.23 (-0.86%)
           8 63353.30 ( 0.00%) 63281.22 (-0.11%)
           9 63511.84 ( 0.00%) 63570.37 ( 0.09%)
          10 62708.27 ( 0.00%) 63166.25 ( 0.73%)
          11 62092.81 ( 0.00%) 61787.75 (-0.49%)
          12 61330.11 ( 0.00%) 61036.34 (-0.48%)
          13 61438.37 ( 0.00%) 61994.47 ( 0.90%)
          14 62304.48 ( 0.00%) 62064.90 (-0.39%)
          15 63296.48 ( 0.00%) 62875.16 (-0.67%)
          16 63951.76 ( 0.00%) 63769.09 (-0.29%)

SYSBENCH PPC64
                             -sysbench-pgalloc-delay-sysbench
              sysbench-vanilla     pgalloc-delay
           1  7645.08 ( 0.00%)  7467.43 (-2.38%)
           2 14856.67 ( 0.00%) 14558.73 (-2.05%)
           3 21952.31 ( 0.00%) 21683.64 (-1.24%)
           4 27946.09 ( 0.00%) 28623.29 ( 2.37%)
           5 28045.11 ( 0.00%) 28143.69 ( 0.35%)
           6 27477.10 ( 0.00%) 27337.45 (-0.51%)
           7 26489.17 ( 0.00%) 26590.06 ( 0.38%)
           8 26642.91 ( 0.00%) 25274.33 (-5.41%)
           9 25137.27 ( 0.00%) 24810.06 (-1.32%)
          10 24451.99 ( 0.00%) 24275.85 (-0.73%)
          11 23262.20 ( 0.00%) 23674.88 ( 1.74%)
          12 24234.81 ( 0.00%) 23640.89 (-2.51%)
          13 24577.75 ( 0.00%) 24433.50 (-0.59%)
          14 25640.19 ( 0.00%) 25116.52 (-2.08%)
          15 26188.84 ( 0.00%) 26181.36 (-0.03%)
          16 26782.37 ( 0.00%) 26255.99 (-2.00%)

Again, there is little to conclude here.  While there are a few losses,
the results vary by +/- 8% in some cases.  They are the results of most
concern as there are some large losses but it's also within the variance
typically seen between kernel releases.

The STREAM results varied so little and are so verbose that I didn't
include them here.

The final test stressed how many huge pages can be allocated.  The
absolute number of huge pages allocated are the same with or without the
page.  However, the "unusability free space index" which is a measure of
external fragmentation was slightly lower (lower is better) throughout the
lifetime of the system.  I also measured the latency of how long it took
to successfully allocate a huge page.  The latency was slightly lower and
on X86 and PPC64, more huge pages were allocated almost immediately from
the free lists.  The improvement is slight but there.

[mel@csn.ul.ie: Tested, reworked for less branches]
[czoccolo@gmail.com: fix oops by checking pfn_valid_within()]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Corrado Zoccolo <czoccolo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agotmpfs: insert tmpfs cache pages to inactive list at first
KOSAKI Motohiro [Mon, 24 May 2010 21:31:48 +0000]
tmpfs: insert tmpfs cache pages to inactive list at first

Shaohua Li reported parallel file copy on tmpfs can lead to OOM killer.
This is regression of caused by commit 9ff473b9a7 ("vmscan: evict
streaming IO first").  Wow, It is 2 years old patch!

Currently, tmpfs file cache is inserted active list at first.  This means
that the insertion doesn't only increase numbers of pages in anon LRU, but
it also reduces anon scanning ratio.  Therefore, vmscan will get totally
confused.  It scans almost only file LRU even though the system has plenty
unused tmpfs pages.

Historically, lru_cache_add_active_anon() was used for two reasons.
1) Intend to priotize shmem page rather than regular file cache.
2) Intend to avoid reclaim priority inversion of used once pages.

But we've lost both motivation because (1) Now we have separate anon and
file LRU list.  then, to insert active list doesn't help such priotize.
(2) In past, one pte access bit will cause page activation.  then to
insert inactive list with pte access bit mean higher priority than to
insert active list.  Its priority inversion may lead to uninteded lru
chun.  but it was already solved by commit 645747462 (vmscan: detect
mapped file pages used only once).  (Thanks Hannes, you are great!)

Thus, now we can use lru_cache_add_anon() instead.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoxtensa: includecheck fix: vectors.S
Jaswinder Singh Rajput [Mon, 24 May 2010 21:31:46 +0000]
xtensa: includecheck fix: vectors.S

fix the following 'make includecheck' warnings:

  arch/xtensa/kernel/vectors.S: asm/processor.h is included more than once.
  arch/xtensa/kernel/vectors.S: asm/ptrace.h is included more than once.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoxtensa: convert to asm-generic/hardirq.h
Christoph Hellwig [Mon, 24 May 2010 21:31:46 +0000]
xtensa: convert to asm-generic/hardirq.h

Also remove lots of unused irq_cpustat fields.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoxtensa: set ARCH_KMALLOC_MINALIGN
FUJITA Tomonori [Mon, 24 May 2010 21:31:45 +0000]
xtensa: set ARCH_KMALLOC_MINALIGN

Architectures that handle DMA-non-coherent memory need to set
ARCH_KMALLOC_MINALIGN to make sure that kmalloc'ed buffer is DMA-safe: the
buffer doesn't share a cache with the others.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6
Linus Torvalds [Mon, 24 May 2010 15:05:29 +0000]
Merge git://git./linux/kernel/git/davem/ide-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6:
  cmd640: fix kernel oops in test_irq() method
  pdc202xx_old: ignore "FIFO empty" bit in test_irq() method
  pdc202xx_old: wire test_irq() method for PDC2026x
  IDE: pass IRQ flags to the IDE core
  ide: fix comment typo in ide.h

9 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier...
Linus Torvalds [Mon, 24 May 2010 15:02:58 +0000]
Merge branch 'for-linus' of git://git./linux/kernel/git/vapier/blackfin

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin: (30 commits)
  Blackfin: SMP: fix continuation lines
  Blackfin: acvilon: fix timeout usage for I2C
  Blackfin: fix typo in BF537 IRQ comment
  Blackfin: unify duplicate MEM_MT48LC32M8A2_75 kconfig options
  Blackfin: set ARCH_KMALLOC_MINALIGN
  Blackfin: use atomic kmalloc in L1 alloc so it too can be atomic
  Blackfin: another year of changes (update copyright in boot log)
  Blackfin: optimize strncpy a bit
  Blackfin: isram: clean up ITEST_COMMAND macro and improve the selftests
  Blackfin: move string functions to normal lib/ assembly
  Blackfin: SIC: cut down on IAR MMR reads a bit
  Blackfin: bf537-minotaur: fix build errors due to header changes
  Blackfin: kgdb: pass up the CC register instead of a 0 stub
  Blackfin: handle HW errors in the new "FAULT" printing code
  Blackfin: show the whole accumulator in the pseudo DBG insn
  Blackfin: support all possible registers in the pseudo instructions
  Blackfin: add support for the DBG (debug output) pseudo insn
  Blackfin: change the BUG opcode to an unused 16-bit opcode
  Blackfin: allow NMI watchdog to be used w/RETN as a scratch reg
  Blackfin: add support for the DBGA (debug assert) pseudo insn
  ...

9 years agoMerge branch 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic...
Linus Torvalds [Mon, 24 May 2010 15:01:10 +0000]
Merge branch 'bkl/ioctl' of git://git./linux/kernel/git/frederic/random-tracing

* 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
  uml: Pushdown the bkl from harddog_kern ioctl
  sunrpc: Pushdown the bkl from sunrpc cache ioctl
  sunrpc: Pushdown the bkl from ioctl
  autofs4: Pushdown the bkl from ioctl
  uml: Convert to unlocked_ioctls to remove implicit BKL
  ncpfs: BKL ioctl pushdown
  coda: Clean-up whitespace problems in pioctl.c
  coda: BKL ioctl pushdown
  drivers: Push down BKL into various drivers
  isdn: Push down BKL into ioctl functions
  scsi: Push down BKL into ioctl functions
  dvb: Push down BKL into ioctl functions
  smbfs: Push down BKL into ioctl function
  coda/psdev: Remove BKL from ioctl function
  um/mmapper: Remove BKL usage
  sn_hwperf: Kill BKL usage
  hfsplus: Push down BKL into ioctl function

9 years agoMerge git://git.infradead.org/battery-2.6
Linus Torvalds [Mon, 24 May 2010 15:00:13 +0000]
Merge git://git.infradead.org/battery-2.6

* git://git.infradead.org/battery-2.6:
  ds2760_battery: Document ABI change
  ds2760_battery: Make charge_now and charge_full writeable
  power_supply: Add support for writeable properties
  power_supply: Use attribute groups
  power_supply: Add test_power driver
  tosa_battery: Fix build error due to direct driver_data usage
  wm97xx_battery: Quieten sparse warning (bat_set_pdata not declared)
  ds2782_battery: Get rid of magic numbers in driver_data
  ds2782_battery: Add support for ds2786 battery gas gauge
  pda_power: Add function callbacks for suspend and resume
  wm831x_power: Use genirq
  Driver for Zipit Z2 battery chip
  ds2782_battery: Fix clientdata on removal

9 years agoMerge branch 'timers-for-linus-urgent' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Mon, 24 May 2010 14:59:17 +0000]
Merge branch 'timers-for-linus-urgent' of git://git./linux/kernel/git/tip/linux-2.6-tip

* 'timers-for-linus-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  timers: Fix slack calculation for expired timers
  timekeeping: Fix timezone update

9 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6
Linus Torvalds [Mon, 24 May 2010 14:58:28 +0000]
Merge git://git./linux/kernel/git/lethal/sh-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (25 commits)
  sh: fix up sh7785lcr_32bit_defconfig.
  arch/sh/lib/strlen.S: Checkpatch cleanup
  sh: fix up sh7786 dmaengine build.
  sh: guard cookie consistency across termination in the DMA driver
  sh: prevent the DMA driver from unloading, while in use
  sh: fix Oops in the serial SCI driver
  sh: allow platforms to specify SD-card supported voltages
  mmc: let MFD's provide supported Vdd card voltages to tmio_mmc
  sh: disable SD-card write-protection detection on kfr2r09
  mfd: pass platform flags down to the tmio_mmc driver
  tmio: add a platform flag to disable card write-protection detection
  sh: Add SDHI DMA support to migor
  sh: Add SDHI DMA support to kfr2r09
  sh: Add SDHI DMA support to ms7724se
  sh: Add SDHI DMA support to ecovec
  mmc: add DMA support to tmio_mmc driver, when used on SuperH
  sh: prepare the SDHI MFD driver to pass DMA configuration to tmio_mmc.c
  mmc: prepare tmio_mmc for passing of DMA configuration from the MFD cell
  sh: add DMA slave definitions to sh7724
  sh: add DMA slaves for two SDHI controllers to sh7722
  ...

9 years agoMerge branch 'for-linus' of git://git.open-osd.org/linux-open-osd
Linus Torvalds [Mon, 24 May 2010 14:57:41 +0000]
Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd

* 'for-linus' of git://git.open-osd.org/linux-open-osd:
  exofs: confusion between kmap() and kmap_atomic() api
  exofs: Add default address_space_operations

9 years agoRevert "ath9k: Group Key fix for VAPs"
Linus Torvalds [Mon, 24 May 2010 14:45:43 +0000]
Revert "ath9k: Group Key fix for VAPs"

This reverts commit 03ceedea972a82d343fa5c2528b3952fa9e615d5, since it
breaks resume from suspend-to-ram on Rafael's Acer Ferrari One.
NetworkManager thinks everything is ok, but it can't connect to the AP
to get an IP address after the resume.

In fact, it even breaks resume for non-ath9k chipsets: reverting it also
fixes Rafael's Toshiba Protege R500 with the iwlagn driver.  As Johannes
says:

  "Indeed, this patch needs to be reverted. That mac80211 change is wrong
   and completely unnecessary."

Reported-and-requested-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Daniel Yingqiang Ma <yma.cool@gmail.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6
Linus Torvalds [Mon, 24 May 2010 14:41:47 +0000]
Merge git://git./linux/kernel/git/hirofumi/fatfs-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6:
  fat: convert to unlocked_ioctl
  fat: Cleanup nls_unload() usage
  fat: use pack_hex_byte() instead of custom one

9 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh...
Linus Torvalds [Mon, 24 May 2010 14:41:13 +0000]
Merge branch 'for-linus' of git://git./linux/kernel/git/ericvh/v9fs

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: Optimize TCREATE by eliminating a redundant fid clone.
  9p: cleanup: remove unneeded assignment
  9p: Add mksock support
  fs/9p: Make sure we properly instantiate dentry.
  9p: add 9P2000.L rename operation
  9p: add 9P2000.L statfs operation
  9p: VFS switches for 9p2000.L: VFS switches
  9p: VFS switches for 9p2000.L: protocol and client changes

9 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph...
Linus Torvalds [Mon, 24 May 2010 14:37:52 +0000]
Merge branch 'for-linus' of git://git./linux/kernel/git/sage/ceph-client

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (59 commits)
  ceph: reuse mon subscribe message instead of allocated anew
  ceph: avoid resending queued message to monitor
  ceph: Storage class should be before const qualifier
  ceph: all allocation functions should get gfp_mask
  ceph: specify max_bytes on readdir replies
  ceph: cleanup pool op strings
  ceph: Use kzalloc
  ceph: use common helper for aborted dir request invalidation
  ceph: cope with out of order (unsafe after safe) mds reply
  ceph: save peer feature bits in connection structure
  ceph: resync headers with userland
  ceph: use ceph. prefix for virtual xattrs
  ceph: throw out dirty caps metadata, data on session teardown
  ceph: attempt mds reconnect if mds closes our session
  ceph: clean up send_mds_reconnect interface
  ceph: wait for mds OPEN reply to indicate reconnect success
  ceph: only send cap releases when mds is OPEN|HUNG
  ceph: dicard cap releases on mds restart
  ceph: make mon client statfs handling more generic
  ceph: drop src address(es) from message header [new protocol feature]
  ...

9 years agoMerge branch 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6
Linus Torvalds [Mon, 24 May 2010 14:37:38 +0000]
Merge branch 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6

* 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6:
  of: change of_match_device to work with struct device
  of: Remove duplicate fields from of_platform_driver
  drivercore: Add of_match_table to the common device drivers
  arch/microblaze: Move dma_mask from of_device into pdev_archdata
  arch/powerpc: Move dma_mask from of_device into pdev_archdata
  of: eliminate of_device->node and dev_archdata->{of,prom}_node
  of: Always use 'struct device.of_node' to get device node pointer.
  i2c/of: Allow device node to be passed via i2c_board_info
  driver-core: Add device node pointer to struct device
  of: protect contents of of_platform.h and of_device.h
  of/flattree: Make unflatten_device_tree() safe to call from any arch
  of/flattree: make of_fdt.h safe to unconditionally include.

9 years agoMerge branch 'slab-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penber...
Linus Torvalds [Mon, 24 May 2010 14:33:43 +0000]
Merge branch 'slab-for-linus' of git://git./linux/kernel/git/penberg/slab-2.6

* 'slab-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Use alloc_pages_exact_node() for page allocation
  slub: __kmalloc_node_track_caller should trace kmalloc_large_node case
  slub: Potential stack overflow
  crypto: Use ARCH_KMALLOC_MINALIGN for CRYPTO_MINALIGN now that it's exposed
  mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slub_def.h>
  mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slob_def.h>
  mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slab_def.h>
  slab: Fix missing DEBUG_SLAB last user
  slab: add memory hotplug support
  slab: Fix continuation lines

9 years agoDocumentation: update SubmitChecklist for O=objdir and kconfig testing
Randy Dunlap [Mon, 24 May 2010 00:02:30 +0000]
Documentation: update SubmitChecklist for O=objdir and kconfig testing

Add build testing using 'O=builddir'.

Add build testing with various kconfig symbols disabled, listing
common ones that are known to cause build problems.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agofusion: fix kernel-doc notation
Ben Hutchings [Mon, 24 May 2010 00:02:30 +0000]
fusion: fix kernel-doc notation

The function name must be followed by a space, hypen, space, and a
short description.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoscsi_scan.c: fix/convert functions to use kernel-doc
Randy Dunlap [Mon, 24 May 2010 00:02:30 +0000]
scsi_scan.c: fix/convert functions to use kernel-doc

scsi_scan.c: fix incorrectly formatted kernel-doc notation
& convert documentation of 2 functions into kernel-doc.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoDocumentation/vm: use better value for MAP_HUGETLB
Carlo Marcelo Arenas Belon [Mon, 24 May 2010 00:02:30 +0000]
Documentation/vm: use better value for MAP_HUGETLB

documentation: slightly more correct value for MAP_HUGETLB in map_hugetlb.c

still not correct for alpha, mips, parisc or xtensa but working out of
the box in the most common architectures without having to deal with
complicated macros or including architecture specific headers.

Signed-off-by: Carlo Marcelo Arenas Belon <carenas@sajinet.com.pe>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoDocumentation/timers/hpet_example: drop duplicate header files
Andrea Gelmini [Mon, 24 May 2010 00:02:30 +0000]
Documentation/timers/hpet_example: drop duplicate header files

Documentation/timers/hpet_example.c: fcntl.h is included more than once.
Documentation/timers/hpet_example.c: signal.h is included more than once.

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoDocumentation/development-process: add staging & mmotm info
Randy Dunlap [Mon, 24 May 2010 00:02:30 +0000]
Documentation/development-process: add staging & mmotm info

Update explanation of mmotm.
Add explanation of drivers/staging/.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agoDocumentation/development-process: add maintainers and git info
Randy Dunlap [Mon, 24 May 2010 00:02:30 +0000]
Documentation/development-process: add maintainers and git info

Add info on maintainers and persistent posting.
Update git home page.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agodocbook: make mtd nand module init static
H Hartley Sweeten [Mon, 24 May 2010 00:02:30 +0000]
docbook: make mtd nand module init static

In the example the module_init function should be static.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9 years agotimers: Fix slack calculation for expired timers
Jeff Chua [Sun, 23 May 2010 23:16:24 +0000]
timers: Fix slack calculation for expired timers

commit 3bbb9ec946 (timers: Introduce the concept of timer slack for
legacy timers) does not take the case into account when the timer is
already expired. This broke wireless drivers.

The solution is not to apply slack to already expired timers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>

9 years agotimekeeping: Fix timezone update
Thomas Gleixner [Sun, 23 May 2010 06:14:45 +0000]
timekeeping: Fix timezone update

commit 64ce4c2f (time: Clean up warp_clock()) breaks the timezone
update in a very subtle way. To avoid the direct access to timekeeping
internals it adds the timezone delta to the current time with
timespec_add_safe(). This works nicely when the timezone delta is > 0.
If timezone delta is < 0 then the wrap check in timespec_add_safe()
triggers and timespec_add_safe() returns TIME_MAX and screws up
timekeeping completely.

The comment above timespec_add_safe() says:
    It's assumed that both values are valid (>= 0)

Add the timezone seconds adjustment directly.

Reported-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

9 years agosh: fix up sh7785lcr_32bit_defconfig.
Paul Mundt [Sun, 23 May 2010 23:33:53 +0000]
sh: fix up sh7785lcr_32bit_defconfig.

The build scripts inadvertently dropped this down to 29-bit, fix it
back up.

Reported-by: Raul Porcel <armin76@gentoo.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

9 years agoarch/sh/lib/strlen.S: Checkpatch cleanup
Andrea Gelmini [Sun, 23 May 2010 20:02:06 +0000]
arch/sh/lib/strlen.S: Checkpatch cleanup

arch/sh/lib/strlen.S:38: ERROR: trailing whitespace

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

9 years agoBlackfin: SMP: fix continuation lines
Joe Perches [Sat, 27 Mar 2010 02:27:51 +0000]
Blackfin: SMP: fix continuation lines

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

9 years agoBlackfin: acvilon: fix timeout usage for I2C
Wolfram Sang [Sun, 4 Apr 2010 14:04:16 +0000]
Blackfin: acvilon: fix timeout usage for I2C

The timeout value is in jiffies, so it should be using HZ, not a plain
number. As '10000' is ambiguous, 1HZ is used as conservative default.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Valentin Yakovenkov <yakovenkov@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

9 years agoBlackfin: fix typo in BF537 IRQ comment
Michael Hennerich [Fri, 21 May 2010 09:36:51 +0000]
Blackfin: fix typo in BF537 IRQ comment

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

9 years agoBlackfin: unify duplicate MEM_MT48LC32M8A2_75 kconfig options
Mike Frysinger [Thu, 20 May 2010 04:26:54 +0000]
Blackfin: unify duplicate MEM_MT48LC32M8A2_75 kconfig options

Reported-by: Christoph Egger <siccegge@cs.fau.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

9 years agoBlackfin: set ARCH_KMALLOC_MINALIGN
FUJITA Tomonori [Thu, 20 May 2010 03:21:38 +0000]
Blackfin: set ARCH_KMALLOC_MINALIGN

Architectures that handle DMA-non-coherent memory need to set
ARCH_KMALLOC_MINALIGN to make sure that kmalloc'ed buffer is DMA-safe:
the buffer doesn't share a cache with the others.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

9 years agoBlackfin: use atomic kmalloc in L1 alloc so it too can be atomic
Mike Frysinger [Tue, 11 May 2010 04:43:19 +0000]
Blackfin: use atomic kmalloc in L1 alloc so it too can be atomic

Some drivers allocate L1 SRAM in atomic contexts, so make sure these
functions also use GFP_ATOMIC to avoid BUG()'s.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

9 years agoBlackfin: another year of changes (update copyright in boot log)
Mike Frysinger [Mon, 10 May 2010 05:21:50 +0000]
Blackfin: another year of changes (update copyright in boot log)

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

9 years agoBlackfin: optimize strncpy a bit
Robin Getz [Tue, 4 May 2010 14:59:21 +0000]
Blackfin: optimize strncpy a bit

Add a little strncpy optimization which can easily cut boot time by 20%.

When the kernel is booting with initramfs, it builds up the filesystem
from a cpio archive by calling strncpy_from_user() via fs/namei.c's
do_getname() on every file in the archive (which can be lots) with a
length of PATH_MAX (1024).  This causes the dest of the strncpy to be
padded with many NUL bytes.

This optimization mostly causes these NUL bytes to be padded with a call
to memset() which is already optimized for filling memory quickly, but
the hardware loop helps a little bit as well.

Boot time measured with 'loglevel=0' so UART speed doesn't get in the way.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

9 years agoBlackfin: isram: clean up ITEST_COMMAND macro and improve the selftests
Mike Frysinger [Tue, 4 May 2010 04:14:08 +0000]
Blackfin: isram: clean up ITEST_COMMAND macro and improve the selftests

The IADDR2DTEST() macro had some duplicated logic with bit 11 and some
incorrect comments, so scrub all of that.

In order to verify these aren't a problem (and won't be in the future),
extend the self tests to operate on as much L1 SRAM as possible.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

9 years agoBlackfin: move string functions to normal lib/ assembly
Robin Getz [Mon, 3 May 2010 17:23:20 +0000]
Blackfin: move string functions to normal lib/ assembly

Since 'extern inline' doesn't work correctly in the context of the Linux
kernel (too many overriding defines), move the string functions to normal
lib/ assembly files (like the existing mem funcs).  This avoids the forced
inline all over the kernel and allows us to place them constantly in L1.

This also avoids some module failures when gcc inserts calls to string
functions but the kernel build system doesn't fully consult the library
archives.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

9 years agoBlackfin: SIC: cut down on IAR MMR reads a bit
Mike Frysinger [Thu, 22 Apr 2010 21:15:00 +0000]
Blackfin: SIC: cut down on IAR MMR reads a bit

Tweak the for loops that operate on the SIC IAR system MMRs to avoid
re-reading them multiple times in a row.  System MMRs are a little
slower to access, so avoid the penalty when possible.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>