FUJITA Tomonori [Wed, 10 Mar 2010 23:23:42 +0000 (15:23 -0800)]
Documentation: convert PCI-DMA-mapping.txt to use the generic DMA API
- replace the PCI DMA API (i.e. pci_dma_*) with the generic DMA API.
- make the document more generic (use the PCI specific explanation as
an example).
[akpm@linux-foundation.org: fix things Randy noticed] Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: "David S. Miller" <davem@davemloft.net> Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:40 +0000 (15:23 -0800)]
dma-mapping: powerpc: use generic pci_set_dma_mask and pci_set_consistent_dma_mask
This converts powerpc to use the generic pci_set_dma_mask and
pci_set_consistent_dma_mask (drivers/pci/pci.c).
The generic pci_set_dma_mask does what powerpc's pci_set_dma_mask does.
Unlike powerpc's pci_set_consistent_dma_mask, the gneric
pci_set_consistent_dma_mask sets only coherent_dma_mask. It doesn't work
for powerpc? pci_set_consistent_dma_mask API should set only
coherent_dma_mask?
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Greg KH <greg@kroah.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dma_set_coherent_mask corresponds to pci_set_consistent_dma_mask. This is
necessary to move to the generic device model DMA API from the PCI bus
specific API in the long term.
dma_set_coherent_mask works in the exact same way that
pci_set_consistent_dma_mask does. So this patch also changes
pci_set_consistent_dma_mask to call dma_set_coherent_mask.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: James Bottomley <James.Bottomley@suse.de> Cc: David S. Miller <davem@davemloft.net> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Greg KH <greg@kroah.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:38 +0000 (15:23 -0800)]
dma-mapping: pci: convert pci_set_dma_mask to call dma_set_mask
This changes pci_set_dma_mask to call the generic DMA API, dma_set_mask.
pci_set_dma_mask (in drivers/pci/pci.c) does the same things that
dma_set_mask does on all the architectures that use pci_set_dma_mask;
calls dma_supprted and sets dev->dma_mask. So we safely change
pci_set_dma_mask to simply call dma_set_mask.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: James Bottomley <James.Bottomley@suse.de> Cc: David S. Miller <davem@davemloft.net> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Greg KH <greg@kroah.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:37 +0000 (15:23 -0800)]
dma-mapping: alpha: use include/linux/pci-dma-compat.h
This converts Alpha to use include/linux/pci-dma-compat.h. Alpha is the
only architecutre that implements the PCI DMA API in the own way. That
makes it difficult to implement the generic DMA API via the PCI bus
specific DMA API.
The generic DMA API calls the PCI DMA API implementation in
arch/alpha/kernel/pci_iommu.c on non Jensen systems. It calls the DMA API
in arch/alpha/kernel/pci-noop.c on Jensen systems.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Greg KH <greg@kroah.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:35 +0000 (15:23 -0800)]
dma-mapping: sparc: unify 32bit and 64bit dma_set_mask
This patchset transforms the PCI DMA API into the generic device model.
It's one of the reasons why we introduced the generic DMA API long ago;
driver writers are always able to use the generic DMA API with any bus
instead of using bus specific DMA APIs such as pci_map_single,
sbus_map_single, etc (only two bus specific APIs exist now; pci and ssb).
Some of the PCI DMA API are already implented on the top of the generic
DMA API (include/asm-generic/pci-dma-compat.h). But there are some
exceptions. This patchset finishes the transformation.
This patch:
sparc has two dma_set_mask implementations for 32bit and 64bit. They are
same except for the error returned value. We can safely unify them since
the error returned value doesn't matter as long as it is negative (as
DMA-API.txt describes).
This patch also changes dma_set_mask not to call
pci_set_dma_mask. Instead, dma_set_mask does the same thing that
pci_set_dma_mask does. This change enables ut to change
pci_set_dma_mask to call dma_set_mask; we can implement
pci_set_dma_mask as pci-dma-compat.h does.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: David Miller <davem@davemloft.net> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: James Bottomley <James.Bottomley@suse.de> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Greg KH <greg@kroah.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:33 +0000 (15:23 -0800)]
dma-mapping: mn10300: remove the obsolete and unnecessary DMA API comments
pci_dma_sync_single was obsoleted long ago.
All the comments are generic, not architecture specific, simply describes
some of the DMA-API (and the same comments are in other files).
Documentation/DMA-API.txt have more detailed descriptions.
This removes the above obsolete and unnecessary DMA API
comments. Let's describe the DMA API in only
Documentation/DMA-API.txt.
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:32 +0000 (15:23 -0800)]
dma-mapping: blackfin: remove the obsolete and unnecessary DMA API comments
pci_dma_sync_single was obsoleted long ago.
All the comments are generic, not architecture specific, simply describes
some of the DMA-API (and the same comments are in other files).
Documentation/DMA-API.txt have more detailed descriptions.
This removes the above obsolete and unnecessary DMA API comments. Let's
describe the DMA API in only Documentation/DMA-API.txt.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:32 +0000 (15:23 -0800)]
dma-mapping: frv: remove the obsolete and unnecessary DMA API comments
pci_dma_sync_single was obsoleted long ago.
All the comments are generic, not architecture specific, simply describes
some of the DMA-API (and frv has the same comments in three files).
Documentation/DMA-API.txt have more detailed descriptions.
This removes the above obsolete and unnecessary DMA API comments. Let's
describe the DMA API in only Documentation/DMA-API.txt.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: David Howells <dhowells@redhat.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The API corresponds to the pci_unmap state API. We'll move to this new
generic API from the PCI specific API in the long term. As
include/asm-generic/pci-dma-compat.h does, the pci_unmap API simply calls
the new generic API for some time.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: James Bottomley <James.Bottomley@suse.de> Cc: David S. Miller <davem@davemloft.net> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:30 +0000 (15:23 -0800)]
pci-dma: add linux/pci-dma.h to linux/pci.h
All the architectures properly set NEED_DMA_MAP_STATE now so we can safely
add linux/pci-dma.h to linux/pci.h and remove the linux/pci-dma.h
inclusion in arch's asm/pci.h
This enables us to remove lots of the duplication in architecture
implementations since there are only two ways to define the API.
If architectures define CONFIG_NEED_DMA_MAP_STATE, they get the real
definition of pci_unmap state API. If not, they get the noop definition.
In the long term, it's better to replace the API with the generic device
model API such as DECLARE_DMA_UNMAP_ADDR. We can map the API to the
generic one (like dma-mapping-compat.h does). This patch also makes the
migration process easier. We can remove this file after the migration.
It might be simpler to add the API to include/linux/pci.h but looks it's
already too large. We'll remove pci-dma.h after finishing moving to the
generic device model. So I put the API to a separate file.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: David Howells <dhowells@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Helge Deller <deller@gmx.de> Cc: James Bottomley <James.Bottomley@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Zankel <chris@zankel.net> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:19 +0000 (15:23 -0800)]
um: remove dma_sync_single_range
dma_sync_single_for_cpu/for_device supports a partial sync so there is no
point to have dma_sync_single_range (also dma_sync_single was obsoleted
long ago, replaced with dma_sync_single_for_cpu/for_device).
There is no user of dma_sync_single_range() in mainline and only Alpha
architecture supports dma_sync_single_range(). So it's unlikely that
someone out of the tree uses it.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Jeff Dike <jdike@addtoit.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:19 +0000 (15:23 -0800)]
alpha: remove dma_sync_single_range
dma_sync_single_for_cpu/for_device supports a partial sync so there is no
point to have dma_sync_single_range (also dma_sync_single was obsoleted
long ago, replaced with dma_sync_single_for_cpu/for_device).
There is no user of dma_sync_single_range() in mainline and only Alpha
architecture supports dma_sync_single_range(). So it's unlikely that
someone out of the tree uses it.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Acked-by: Matt Turner <mattst88@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dma_sync_single_for_cpu/for_device supports a partial sync so there is no
point to have dma_sync_single_range (also dma_sync_single was obsoleted
long ago, replaced with dma_sync_single_for_cpu/for_device).
There is no user of dma_sync_single_range() in mainline and only Alpha
architecture supports dma_sync_single_range(). So it's unlikely that
someone out of the tree uses it.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: David Miller <davem@davemloft.net> Acked-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It was unclear that the API permits a partial sync (some network drivers
already do though). I made it clear that the sync_single API can do a
partial sync but the sync_sg API can't.
We could do a partial sync with the sync_sg API too, however, it's
difficult for driver writers to correctly use the sync_sg API for a
partial sync since the scatterlists passed in to the mapping API can't be
modified. It's unlikely that driver writers want to do a partial sync
with the sync_sg API (because the sync_sg API are usually used for block
drivers). So I think that it's better to forbid a partial sync with the
sync_sg API.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: David Miller <davem@davemloft.net> Acked-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori [Wed, 10 Mar 2010 23:23:15 +0000 (15:23 -0800)]
Documentation/DMA-API.txt: remove deprecated function descriptions
dma_sync_single(), pci_dma_sync_single(), dma_sync_sg(), and
pci_dma_sync_sg() are deprecated. We should not advertise them.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Joerg Roedel <joro@8bytes.org> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Peter Tyser [Wed, 10 Mar 2010 23:23:15 +0000 (15:23 -0800)]
edac: e752x: add dram scrubbing support
Add support to scrub DRAM using the e752x integrated memory scrubbing
engine. The e7320/7520/e7525 chipsets support scrubbing at one rate while
the i3100 chipset supports a normal and fast rate.
A similar patch was originally sent back in 2008:
http://sourceforge.net/mailarchive/forum.php?thread_name=1204835866.25206.70.camel@localhost.localdomain&forum_name=bluesmoke-devel
This version has the following updates:
- Use 16-bit PCI config cycles to access MCHSCRB register
e7320/7520/e7525 docs say register is 16bits wide, i3100 says 8. I
tested 16bits on the i3100 to be safe.
- Recalcuate and round actual scrub rates
The changes have been tested on an i3100-based board.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com> Signed-off-by: Doug Thompson <dougthompson@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Peter Tyser [Wed, 10 Mar 2010 23:23:12 +0000 (15:23 -0800)]
edac: mpc85xx improve SDRAM error reporting
Add the ability to detect the specific data line or ECC line which failed
when printing out SDRAM single-bit errors. An example of a single-bit
SDRAM ECC error is below:
Knowning which specific data or ECC line caused an error can be useful in
tracking down hardware issues such as improperly terminated signals, loose
pins, etc.
Note that this feature is only currently enabled for 64-bit wide data
buses, 32-bit wide bus support should be added.
I don't have any 32-bit wide systems to test on. If someone has one and
is willing to give this patch a shot with the check for a 64-bit data bus
removed it would be much appreciated and I can re-submit with both 32 and
64 bit buses supported.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com> Signed-off-by: Doug Thompson <dougthompson@xmission.com> Cc: Kumar Gala <galak@gate.crashing.org> Cc: Dave Jiang <djiang@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Peter Tyser [Wed, 10 Mar 2010 23:23:11 +0000 (15:23 -0800)]
edac: mpc85xx mask ecc syndrome correctly
With a 64-bit wide data bus only the lowest 8-bits of the ECC syndrome are
relevant. With a 32-bit wide data bus only the lowest 16-bits are
relevant on most architectures.
Without this change, the ECC syndrome displayed can be mildly confusing,
eg:
EDAC MPC85xx MC1: syndrome: 0x25252525
When in reality the ECC syndrome is 0x25.
A variety of Freescale manuals say a variety of different things about how
to decode the CAPTURE_ECC (syndrome) register. I don't have a system with
a 32-bit bus to test on, but I believe the change is correct. It'd be
good to get an ACK from someone at Freescale about this change though.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com> Signed-off-by: Doug Thompson <dougthompson@xmission.com> Cc: Kumar Gala <galak@gate.crashing.org> Cc: Dave Jiang <djiang@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Wed, 10 Mar 2010 23:23:09 +0000 (15:23 -0800)]
pid_ns: zap_pid_ns_processes: use SEND_SIG_NOINFO instead of force_sig()
zap_pid_ns_processes() uses force_sig(SIGKILL) to ensure SIGKILL will be
delivered to sub-namespace inits as well. This is correct, but we are
going to change force_sig_info() semantics. See
http://bugzilla.kernel.org/show_bug.cgi?id=15395#c31
We can use send_sig_info(SEND_SIG_NOINFO) instead, since 614c517d7c00af1b26ded20646b329397d6f51a1 ("signals: SEND_SIG_NOINFO should
be considered as SI_FROMUSER()") SEND_SIG_NOINFO means "from user" and
therefore send_signal() will get the correct from_ancestor_ns = T flag.
Bela Lubkin [Wed, 10 Mar 2010 23:23:07 +0000 (15:23 -0800)]
ipmi: fix slave_addrs setting to actually work
Actually use the slave_addrs module parameter if it is specified, and make
things consistent about passing zero in for the slave address for the
default.
Signed-off-by: Bela Lubkin <blubkin@vmware.com> Signed-off-by: Corey Minyard <minyard@acm.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Martin Wilck [Wed, 10 Mar 2010 23:23:06 +0000 (15:23 -0800)]
ipmi: add parameter to limit CPU usage in kipmid
In some cases kipmid can use a lot of CPU. This adds a way to tune the
CPU used by kipmid to help in those cases. By setting kipmid_max_busy_us
to a value between 100 and 500, it is possible to bring down kipmid CPU
load to practically 0 without loosing too much ipmi throughput
performance. Not setting the value, or setting the value to zero,
operation is unaffected.
Signed-off-by: Martin Wilck <martin.wilck@ts.fujitsu.com> Signed-off-by: Corey Minyard <cminyard@mvista.com> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jiri Slaby [Wed, 10 Mar 2010 23:23:05 +0000 (15:23 -0800)]
ipc: use rlimit helpers
Make sure compiler won't do weird things with limits. E.g. fetching them
twice may return 2 different values after writable limits are implemented.
I.e. either use rlimit helpers added in 3e10e716abf3c71bdb5d86b8f507f9e72236c9cd ("resource: add helpers for
fetching rlimits") or ACCESS_ONCE if not applicable.
Remove unneeded initializations in thread_group_cputime_init() and in
posix_cpu_timers_init_group(). They are useless after kmem_cache_zalloc()
was used in copy_signal().
Signed-off-by: Veaceslav Falico <vfalico@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP. This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't, which is consistent with all architectures using the
modern ptrace code.
The old code only disables the breakpoints on PTRACE_KILL, while after
this patch this also happens for PTRACE_CONT and PTRACE_SYSCALL which
matches the behaviour of the other architetures. I think this is a
bugfixes, but please double verify this is correct.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP. This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.
The way breakpoints are disabled is entirely inconsistent currently, I
tried to make some sense of it, but I suspect all of the content of
ptrace_disable should be moved into user_disable_single_step, this
defintively needs some revisting as the current patch changes behaviour in
not quite designed ways.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT and
PTRACE_KILL. This also makes PTRACE_SINGLESTEP return -EIO while it
previously succeeded despite not actually causing any kind of single
stepping.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP. This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.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>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP. This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.
XXX: I'm not sure arch_has_single_step() is placed in the exactly correct
location, please verify in which of the ptrace headers it should really
be.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT and
PTRACE_KILL.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT and
PTRACE_KILL. This also makes PTRACE_SINGLESTEP return -EIO while it
previously succeeded despite not actually causing any kind of single
stepping.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Acked-by: Michal Simek <monstr@monstr.eu> Cc: John Williams <john.williams@petalogix.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP. m68knommu already defines the
nessecary user_enable_single_step and user_disable_single_step functions
for this.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Acked-by: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP. This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP. This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.
Currently avr32 doesn't implement any code to disable single stepping when
one of the non-syscall requests is called which seems wrong, but I've left
it as-is for now.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP. This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't and the single stepping disable only happens if the
tracee process isn't a zombie yet, which is consistent with all
architectures using the modern ptrace code.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.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>
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP. This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.
Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't, which is consistent with all architectures using the
modern ptrace code.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Acked-by: Matt Turner <mattst88@gmail.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace: move user_enable_single_step & co prototypes to linux/ptrace.h
While in theory user_enable_single_step/user_disable_single_step/
user_enable_blockstep could also be provided as an inline or macro there's
no good reason to do so, and having the prototype in one places keeps code
size and confusion down.
Roland said:
The original thought there was that user_enable_single_step() et al
might well be only an instruction or three on a sane machine (as if we
have any of those!), and since there is only one call site inlining
would be beneficial. But I agree that there is no strong reason to care
about inlining it.
As to the arch changes, there is only one thought I'd add to the
record. It was always my thinking that for an arch where
PTRACE_SINGLESTEP does text-modifying breakpoint insertion,
user_enable_single_step() should not be provided. That is,
arch_has_single_step()=>true means that there is an arch facility with
"pure" semantics that does not have any unexpected side effects.
Inserting a breakpoint might do very unexpected strange things in
multi-threaded situations. Aside from that, it is a peculiar side
effect that user_{enable,disable}_single_step() should cause COW
de-sharing of text pages and so forth. For PTRACE_SINGLESTEP, all these
peculiarities are the status quo ante for that arch, so having
arch_ptrace() itself do those is one thing. But for building other
things in the future, it is nicer to have a uniform "pure" semantics
that arch-independent code can expect.
OTOH, all such arch issues are really up to the arch maintainer. As
of today, there is nothing but ptrace using user_enable_single_step() et
al so it's a distinction without a practical difference. If/when there
are other facilities that use user_enable_single_step() and might care,
the affected arch's can revisit the question when someone cares about
the quality of the arch support for said new facility.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace: use ptrace_request() in the remaining architectures
Use ptrace_request() in the three remaining architectures that didn't use it
(m68knommu, h8300, microblaze). This means:
- ptrace_request now handles PTRACE_{PEEK,POKE}{TEXT,DATA} and PTRACE_DETATCH
calls that were previously called directly, or in case of h8300 even open
coded.
- adds new support for PTRACE_SETOPTIONS/PTRACE_GETEVENTMSG/
PTRACE_GETSIGINFO/PTRACE_SETSIGINFO
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Michal Simek <monstr@monstr.eu> Acked-by: Greg Ungerer <gerg@uclinux.org> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nishimura-san have been working for memcg very good. His review and tests
give us much improvements and account migraiton which he is now
challenging is really important.
If page fault's return code is VM_FAULT_OOM, page_fault_out_of_memory() is
called. But if it's caused by memcg, OOM should have been already
invoked.
Then, I added a patch: a636b327f731143ccc544b966cfd8de6cb6d72c6. That
patch records last_oom_jiffies for memcg's sub-hierarchy and prevents
page_fault_out_of_memory from being invoked in near future.
But Nishimura-san reported that check by jiffies is not enough when the
system is terribly heavy.
This patch changes memcg's oom logic as.
* If memcg causes OOM-kill, continue to retry.
* remove jiffies check which is used now.
* add memcg-oom-lock which works like perzone oom lock.
* If current is killed(as a process), bypass charge.
Something more sophisticated can be added but this pactch does
fundamental things.
TODO:
- add oom notifier
- add permemcg disable-oom-kill flag and freezer at oom.
- more chances for wake up oom waiter (when changing memory limit etc..)
cgroups: remove events before destroying subsystem state objects
Events should be removed after rmdir of cgroup directory, but before
destroying subsystem state objects. Let's take reference to cgroup
directory dentry to do that.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dan Malek <dan@embeddedalley.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cgroups: fix race between userspace and kernelspace
Notify userspace about cgroup removing only after rmdir of cgroup
directory to avoid race between userspace and kernelspace.
eventfd are used to notify about two types of event:
- control file-specific, like crossing memory threshold;
- cgroup removing.
To understand what really happen, userspace can check if the cgroup still
exists. To avoid race beetween userspace and kernelspace we have to
notify userspace about cgroup removing only after rmdir of cgroup
directory.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dan Malek <dan@embeddedalley.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Presently, if panic_on_oom=2, the whole system panics even if the oom
happend in some special situation (as cpuset, mempolicy....). Then,
panic_on_oom=2 means painc_on_oom_always.
Now, memcg doesn't check panic_on_oom flag. This patch adds a check.
BTW, how it's useful ?
kdump+panic_on_oom=2 is the last tool to investigate what happens in
oom-ed system. When a task is killed, the sysytem recovers and there will
be few hint to know what happnes. In mission critical system, oom should
never happen. Then, panic_on_oom=2+kdump is useful to avoid next OOM by
knowing precise information via snapshot.
TODO:
- For memcg, it's for isolate system's memory usage, oom-notiifer and
freeze_at_oom (or rest_at_oom) should be implemented. Then, management
daemon can do similar jobs (as kdump) or taking snapshot per cgroup.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Memcg has 2 eventcountes which counts "the same" event. Just usages are
different from each other. This patch tries to reduce event counter.
Now logic uses "only increment, no reset" counter and masks for each
checks. Softlimit chesk was done per 1000 evetns. So, the similar check
can be done by !(new_counter & 0x3ff). Threshold check was done per 100
events. So, the similar check can be done by (!new_counter & 0x7f)
ALL event checks are done right after EVENT percpu counter is updated.
Presently, move_task does "batched" precharge. Because res_counter or
css's refcnt are not-scalable jobs for memcg, try_charge_().. tend to be
done in batched manner if allowed.
Now, softlimit and threshold check their event counter in try_charge, but
the charge is not a per-page event. And event counter is not updated at
charge(). Moreover, precharge doesn't pass "page" to try_charge() and
softlimit tree will be never updated until uncharge() causes an event."
So the best place to check the event counter is commit_charge(). This is
per-page event by its nature. This patch move checks to there.
memcg: use generic percpu instead of private implementation
When per-cpu counter for memcg was implemneted, dynamic percpu allocator
was not very good. But now, we have good one and useful macros. This
patch replaces memcg's private percpu counter implementation with generic
dynamic percpu allocator.
The benefits are
- We can remove private implementation.
- The counters will be NUMA-aware. (Current one is not...)
- This patch makes sizeof struct mem_cgroup smaller. Then,
struct mem_cgroup may be fit in page size on small config.
- About basic performance aspects, see below.
[Before]
# size mm/memcontrol.o
text data bss dec hex filename
24373 2528 4132 31033 7939 mm/memcontrol.o
[page-fault-throuput test on 8cpu/SMP in root cgroup]
# /root/bin/perf stat -a -e page-faults,cache-misses --repeat 5 ./multi-fault-fork 8
Performance counter stats for './multi-fault-fork 8' (5 runs):
[After]
#size mm/memcontrol.o
text data bss dec hex filename
23913 2528 4132 30573 776d mm/memcontrol.o
# /root/bin/perf stat -a -e page-faults,cache-misses --repeat 5 ./multi-fault-fork 8
Performance counter stats for './multi-fault-fork 8' (5 runs):
Text size is reduced.
This performance improvement is not big and will be invisible in real world
applications. But this result shows this patch has some good effect even
on (small) SMP.
Here is a test program I used.
1. fork() processes on each cpus.
2. do page fault repeatedly on each process.
3. after 60secs, kill all childredn and exit.
(3 is necessary for getting stable data, this is improvement from previous one.)
/*
* For avoiding contention in page table lock, FAULT area is
* sparse. If FAULT_LENGTH is too large for your cpus, decrease it.
*/
#define FAULT_LENGTH (2 * 1024 * 1024)
#define PAGE_SIZE 4096
#define MAXNUM (128)
void alarm_handler(int sig)
{
}
void *worker(int cpu, int ppid)
{
void *start, *end;
char *c;
cpu_set_t set;
int i;
pause();
//fprintf(stderr, "run%d", cpu);
while (1) {
for (c = (char*)start; (void *)c < end; c += PAGE_SIZE)
*c = 0;
madvise(start, FAULT_LENGTH, MADV_DONTNEED);
}
return NULL;
}
int main(int argc, char *argv[])
{
int num, i, ret, pid, status;
int pids[MAXNUM];
if (argc < 2)
return 0;
setpgid(0, 0);
signal(SIGALRM, alarm_handler);
num = atoi(argv[1]);
pid = getpid();
for (i = 0; i < num; ++i) {
ret = fork();
if (!ret) {
worker(i, pid);
exit(0);
}
pids[i] = ret;
}
sleep(1);
kill(-pid, SIGALRM);
sleep(60);
for (i = 0; i < num; i++)
kill(pids[i], SIGKILL);
for (i = 0; i < num; i++)
waitpid(pids[i], &status, 0);
return 0;
}
It allows to register multiple memory and memsw thresholds and gets
notifications when it crosses.
To register a threshold application need:
- create an eventfd;
- open memory.usage_in_bytes or memory.memsw.usage_in_bytes;
- write string like "<event_fd> <memory.usage_in_bytes> <threshold>" to
cgroup.event_control.
Application will be notified through eventfd when memory usage crosses
threshold in any direction.
It's applicable for root and non-root cgroup.
It uses stats to track memory usage, simmilar to soft limits. It checks
if we need to send event to userspace on every 100 page in/out. I guess
it's good compromise between performance and accuracy of thresholds.
[akpm@linux-foundation.org: coding-style fixes]
[nishimura@mxp.nes.nec.co.jp: fix documentation merge issue] Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dan Malek <dan@embeddedalley.com> Cc: Vladislav Buzov <vbuzov@embeddedalley.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Alexander Shishkin <virtuoso@slind.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of incrementing counter on each page in/out and comparing it with
constant, we set counter to constant, decrement counter on each page
in/out and compare it with zero. We want to make comparing as fast as
possible. On many RISC systems (probably not only RISC) comparing with
zero is more effective than comparing with a constant, since not every
constant can be immediate operand for compare instruction.
Also, I've renamed MEM_CGROUP_STAT_EVENTS to MEM_CGROUP_STAT_SOFTLIMIT,
since really it's not a generic counter.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dan Malek <dan@embeddedalley.com> Cc: Vladislav Buzov <vbuzov@embeddedalley.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Alexander Shishkin <virtuoso@slind.org> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cgroup: implement eventfd-based generic API for notifications
This patchset introduces eventfd-based API for notifications in cgroups
and implements memory notifications on top of it.
It uses statistics in memory controler to track memory usage.
Output of time(1) on building kernel on tmpfs:
Root cgroup before changes:
make -j2 506.37 user 60.93s system 193% cpu 4:52.77 total
Non-root cgroup before changes:
make -j2 507.14 user 62.66s system 193% cpu 4:54.74 total
Root cgroup after changes (0 thresholds):
make -j2 507.13 user 62.20s system 193% cpu 4:53.55 total
Non-root cgroup after changes (0 thresholds):
make -j2 507.70 user 64.20s system 193% cpu 4:55.70 total
Root cgroup after changes (1 thresholds, never crossed):
make -j2 506.97 user 62.20s system 193% cpu 4:53.90 total
Non-root cgroup after changes (1 thresholds, never crossed):
make -j2 507.55 user 64.08s system 193% cpu 4:55.63 total
This patch:
Introduce the write-only file "cgroup.event_control" in every cgroup.
To register new notification handler you need:
- create an eventfd;
- open a control file to be monitored. Callbacks register_event() and
unregister_event() must be defined for the control file;
- write "<event_fd> <control_fd> <args>" to cgroup.event_control.
Interpretation of args is defined by control file implementation;
eventfd will be woken up by control file implementation or when the
cgroup is removed.
To unregister notification handler just close eventfd.
If you need notification functionality for a control file you have to
implement callbacks register_event() and unregister_event() in the
struct cftype.
[kamezawa.hiroyu@jp.fujitsu.com: Kconfig fix] Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dan Malek <dan@embeddedalley.com> Cc: Vladislav Buzov <vbuzov@embeddedalley.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Alexander Shishkin <virtuoso@slind.org> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-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>
- Adds a new function(__mem_cgroup_put), which takes "count" as a arg and
decrement mem->refcnt by "count".
- Removed res_counter_uncharge, css_put, and mem_cgroup_put from the path
of moving swap account, and consolidate all of them into mem_cgroup_clear_mc.
We cannot do that about mc.to->refcnt.
These changes reduces the overhead from 1.35sec to 0.9sec to move charges
of 1G anonymous memory(including 500MB swap) in my test environment.
This patch is another core part of this move-charge-at-task-migration
feature. It enables moving charges of anonymous swaps.
To move the charge of swap, we need to exchange swap_cgroup's record.
In current implementation, swap_cgroup's record is protected by:
- page lock: if the entry is on swap cache.
- swap_lock: if the entry is not on swap cache.
This works well in usual swap-in/out activity.
But this behavior make the feature of moving swap charge check many
conditions to exchange swap_cgroup's record safely.
So I changed modification of swap_cgroup's recored(swap_cgroup_record())
to use xchg, and define a new function to cmpxchg swap_cgroup's record.
This patch also enables moving charge of non pte_present but not uncharged
swap caches, which can be exist on swap-out path, by getting the target
pages via find_get_page() as do_mincore() does.
This move-charge-at-task-migration feature has extra charges on
"to"(pre-charges) and "from"(left-over charges) during moving charge.
This means unnecessary oom can happen.
- Instead of calling res_counter_uncharge() against the old cgroup in
__mem_cgroup_move_account() everytime, call res_counter_uncharge() at the end
of task migration once.
- removed css_get(&to->css) from __mem_cgroup_move_account() because callers
should have already called css_get(). And removed css_put(&to->css) too,
which was called by callers of move_account on success of move_account.
- Instead of calling __mem_cgroup_try_charge(), i.e. res_counter_charge(),
repeatedly, call res_counter_charge(PAGE_SIZE * count) in can_attach() if
possible.
- Instead of calling css_get()/css_put() repeatedly, make use of coalesce
__css_get()/__css_put() if possible.
These changes reduces the overhead from 1.7sec to 0.6sec to move charges
of 1G anonymous memory in my test environment.
This patch is the core part of this move-charge-at-task-migration feature.
It implements functions to move charges of anonymous pages mapped only by
the target task.
Implementation:
- define struct move_charge_struct and a valuable of it(mc) to remember the
count of pre-charges and other information.
- At can_attach(), get anon_rss of the target mm, call __mem_cgroup_try_charge()
repeatedly and count up mc.precharge.
- At attach(), parse the page table, find a target page to be move, and call
mem_cgroup_move_account() about the page.
- Cancel all precharges if mc.precharge > 0 on failure or at the end of
task move.
[akpm@linux-foundation.org: a little simplification] Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memcg: add interface to move charge at task migration
In current memcg, charges associated with a task aren't moved to the new
cgroup at task migration. Some users feel this behavior to be strange.
These patches are for this feature, that is, for charging to the new
cgroup and, of course, uncharging from the old cgroup at task migration.
This patch adds "memory.move_charge_at_immigrate" file, which is a flag
file to determine whether charges should be moved to the new cgroup at
task migration or not and what type of charges should be moved. This
patch also adds read and write handlers of the file.
This patch also adds no-op handlers for this feature. These handlers will
be implemented in later patches. And you cannot write any values other
than 0 to move_charge_at_immigrate yet.
Ben Blum [Wed, 10 Mar 2010 23:22:11 +0000 (15:22 -0800)]
cgroups: blkio subsystem as module
Modify the Block I/O cgroup subsystem to be able to be built as a module.
As the CFQ disk scheduler optionally depends on blk-cgroup, config options
in block/Kconfig, block/Kconfig.iosched, and block/blk-cgroup.h are
enhanced to support the new module dependency.
Signed-off-by: Ben Blum <bblum@andrew.cmu.edu> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ben Blum [Wed, 10 Mar 2010 23:22:09 +0000 (15:22 -0800)]
cgroups: subsystem module unloading
Provides support for unloading modular subsystems.
This patch adds a new function cgroup_unload_subsys which is to be used
for removing a loaded subsystem during module deletion. Reference
counting of the subsystems' modules is moved from once (at load time) to
once per attached hierarchy (in parse_cgroupfs_options and
rebind_subsystems) (i.e., 0 or 1).
Signed-off-by: Ben Blum <bblum@andrew.cmu.edu> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ben Blum [Wed, 10 Mar 2010 23:22:09 +0000 (15:22 -0800)]
cgroups: subsystem module loading interface
Add interface between cgroups subsystem management and module loading
This patch implements rudimentary module-loading support for cgroups -
namely, a cgroup_load_subsys (similar to cgroup_init_subsys) for use as a
module initcall, and a struct module pointer in struct cgroup_subsys.
Several functions that might be wanted by modules have had EXPORT_SYMBOL
added to them, but it's unclear exactly which functions want it and which
won't.
Signed-off-by: Ben Blum <bblum@andrew.cmu.edu> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ben Blum [Wed, 10 Mar 2010 23:22:07 +0000 (15:22 -0800)]
cgroups: revamp subsys array
This patch series provides the ability for cgroup subsystems to be
compiled as modules both within and outside the kernel tree. This is
mainly useful for classifiers and subsystems that hook into components
that are already modules. cls_cgroup and blkio-cgroup serve as the
example use cases for this feature.
It provides an interface cgroup_load_subsys() and cgroup_unload_subsys()
which modular subsystems can use to register and depart during runtime.
The net_cls classifier subsystem serves as the example for a subsystem
which can be converted into a module using these changes.
Patch #1 sets up the subsys[] array so its contents can be dynamic as
modules appear and (eventually) disappear. Iterations over the array are
modified to handle when subsystems are absent, and the dynamic section of
the array is protected by cgroup_mutex.
Patch #2 implements an interface for modules to load subsystems, called
cgroup_load_subsys, similar to cgroup_init_subsys, and adds a module
pointer in struct cgroup_subsys.
Patch #3 adds a mechanism for unloading modular subsystems, which includes
a more advanced rework of the rudimentary reference counting introduced in
patch 2.
Patch #4 modifies the net_cls subsystem, which already had some module
declarations, to be configurable as a module, which also serves as a
simple proof-of-concept.
Part of implementing patches 2 and 4 involved updating css pointers in
each css_set when the module appears or leaves. In doing this, it was
discovered that css_sets always remain linked to the dummy cgroup,
regardless of whether or not any subsystems are actually bound to it
(i.e., not mounted on an actual hierarchy). The subsystem loading and
unloading code therefore should keep in mind the special cases where the
added subsystem is the only one in the dummy cgroup (and therefore all
css_sets need to be linked back into it) and where the removed subsys was
the only one in the dummy cgroup (and therefore all css_sets should be
unlinked from it) - however, as all css_sets always stay attached to the
dummy cgroup anyway, these cases are ignored. Any fix that addresses this
issue should also make sure these cases are addressed in the subsystem
loading and unloading code.
This patch:
Make subsys[] able to be dynamically populated to support modular
subsystems
This patch reworks the way the subsys[] array is used so that subsystems
can register themselves after boot time, and enables the internals of
cgroups to be able to handle when subsystems are not present or may
appear/disappear.
Signed-off-by: Ben Blum <bblum@andrew.cmu.edu> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cgroup: introduce coalesce css_get() and css_put()
Current css_get() and css_put() increment/decrement css->refcnt one by
one.
This patch add a new function __css_get(), which takes "count" as a arg
and increment the css->refcnt by "count". And this patch also add a new
arg("count") to __css_put() and change the function to decrement the
css->refcnt by "count".
These coalesce version of __css_get()/__css_put() will be used to improve
performance of memcg's moving charge feature later, where instead of
calling css_get()/css_put() repeatedly, these new functions will be used.
No change is needed for current users of css_get()/css_put().
Add cancel_attach() operation to struct cgroup_subsys. cancel_attach()
can be used when can_attach() operation prepares something for the subsys,
but we should rollback what can_attach() operation has prepared if attach
task fails after we've succeeded in can_attach().
Dave Young [Wed, 10 Mar 2010 23:22:02 +0000 (15:22 -0800)]
Documentation/email-clients.txt: update gmail information
Gmail web gui does not work for sending patches now even with firefox
"view source with" extension. It will use windows style line breaks to
wrap lines automatically when sening email.
Rewrite the gmail web gui part of email client documentation.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Martin Bligh <mbligh@mbligh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Wed, 10 Mar 2010 23:22:02 +0000 (15:22 -0800)]
scripts/kernel-doc: fix empty function description section
scripts/kernel-doc mishandles a function that has a multi-line function
short description and no function parameters. The observed problem was
from drivers/scsi/scsi_netlink.c:
/**
* scsi_netlink_init - Called by SCSI subsystem to intialize
* the SCSI transport netlink interface
*
**/
kernel-doc treated the " * " line as a Description: section with only a
newline character in the Description contents. This caused
output_highlight() to complain: "output_highlight got called with no
args?", plus produce a perl call stack backtrace.
The fix is just to ignore Description sections if they only contain "\n".
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Wed, 10 Mar 2010 23:21:58 +0000 (15:21 -0800)]
Documentation/vm/: split txt and source files
Documentation/vm/:
Expose example and tool source files in the Documentation/ directory in
their own files instead of being buried (almost hidden) in readme/txt files.
This should help to prevent bitrot.
This will make them more visible/usable to users who may need
to use them, to developers who may need to test with them, and
to anyone who would fix/update them if they were more visible.
Also, if any of these possibly should not be in the kernel tree at
all, it will be clearer that they are here and we can discuss if
they should be removed.
Also build the recently-added map_hugetlb.c.
Make several functions static to prevent linker warnings.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Eric B Munson <ebmunson@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Wed, 10 Mar 2010 23:21:56 +0000 (15:21 -0800)]
Documentation/laptop/: split txt and source files
Documentation/laptops/laptop-mode.txt:
Expose example and tool source files in the Documentation/ directory in
their own files instead of being buried (almost hidden) in readme/txt files.
This should help to prevent bitrot.
This will make them more visible/usable to users who may need
to use them, to developers who may need to test with them, and
to anyone who would fix/update them if they were more visible.
Also, if any of these possibly should not be in the kernel tree at
all, it will be clearer that they are here and we can discuss if
they should be removed.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Wed, 10 Mar 2010 23:21:56 +0000 (15:21 -0800)]
Documentation/timers/: split txt and source files
Documentation/timers/hpet.txt:
Expose example and tool source files in the Documentation/timers/ directory in
their own files instead of being buried (almost hidden) in readme/txt files.
This should help to prevent bitrot.
This will make them more visible/usable to users who may need
to use them, to developers who may need to test with them, and
to anyone who would fix/update them if they were more visible.
Also, if any of these possibly should not be in the kernel tree at
all, it will be clearer that they are here and we can discuss if
they should be removed.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Code Review / linux-2.6.git / log