[PATCH] zoned vm counters: conversion of nr_pagecache to per zone counter
Christoph Lameter [Fri, 30 Jun 2006 08:55:35 +0000 (01:55 -0700)]
Currently a single atomic variable is used to establish the size of the page
cache in the whole machine.  The zoned VM counters have the same method of
implementation as the nr_pagecache code but also allow the determination of
the pagecache size per zone.

Remove the special implementation for nr_pagecache and make it a zoned counter
named NR_FILE_PAGES.

Updates of the page cache counters are always performed with interrupts off.
We can therefore use the __ variant here.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

13 files changed:
arch/s390/appldata/appldata_mem.c
arch/sparc/kernel/sys_sunos.c
arch/sparc64/kernel/sys_sunos32.c
drivers/base/node.c
fs/proc/proc_misc.c
include/linux/mmzone.h
include/linux/pagemap.h
mm/filemap.c
mm/mmap.c
mm/nommu.c
mm/page_alloc.c
mm/swap_state.c
mm/vmstat.c

index 7915a19..180ba79 100644 (file)
@@ -130,7 +130,8 @@ static void appldata_get_mem_data(void *data)
        mem_data->totalhigh = P2K(val.totalhigh);
        mem_data->freehigh  = P2K(val.freehigh);
        mem_data->bufferram = P2K(val.bufferram);
-       mem_data->cached    = P2K(atomic_read(&nr_pagecache) - val.bufferram);
+       mem_data->cached    = P2K(global_page_state(NR_FILE_PAGES)
+                               - val.bufferram);
 
        si_swapinfo(&val);
        mem_data->totalswap = P2K(val.totalswap);
index 288de27..aa0fb2e 100644 (file)
@@ -196,7 +196,7 @@ asmlinkage int sunos_brk(unsigned long brk)
         * simple, it hopefully works in most obvious cases.. Easy to
         * fool it, but this should catch most mistakes.
         */
-       freepages = get_page_cache_size();
+       freepages = global_page_state(NR_FILE_PAGES);
        freepages >>= 1;
        freepages += nr_free_pages();
        freepages += nr_swap_pages;
index ae5b32f..87ebdf8 100644 (file)
@@ -155,7 +155,7 @@ asmlinkage int sunos_brk(u32 baddr)
         * simple, it hopefully works in most obvious cases.. Easy to
         * fool it, but this should catch most mistakes.
         */
-       freepages = get_page_cache_size();
+       freepages = global_page_state(NR_FILE_PAGES);
        freepages >>= 1;
        freepages += nr_free_pages();
        freepages += nr_swap_pages;
index 8b12323..ae9e3fe 100644 (file)
@@ -69,6 +69,7 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                       "Node %d LowFree:      %8lu kB\n"
                       "Node %d Dirty:        %8lu kB\n"
                       "Node %d Writeback:    %8lu kB\n"
+                      "Node %d FilePages:    %8lu kB\n"
                       "Node %d Mapped:       %8lu kB\n"
                       "Node %d Slab:         %8lu kB\n",
                       nid, K(i.totalram),
@@ -82,6 +83,7 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                       nid, K(i.freeram - i.freehigh),
                       nid, K(ps.nr_dirty),
                       nid, K(ps.nr_writeback),
+                      nid, K(node_page_state(nid, NR_FILE_PAGES)),
                       nid, K(node_page_state(nid, NR_FILE_MAPPED)),
                       nid, K(ps.nr_slab));
        n += hugetlb_report_node_meminfo(nid, buf + n);
index bc7d9ab..1af12fd 100644 (file)
@@ -142,7 +142,8 @@ static int meminfo_read_proc(char *page, char **start, off_t off,
        allowed = ((totalram_pages - hugetlb_total_pages())
                * sysctl_overcommit_ratio / 100) + total_swap_pages;
 
-       cached = get_page_cache_size() - total_swapcache_pages - i.bufferram;
+       cached = global_page_state(NR_FILE_PAGES) -
+                       total_swapcache_pages - i.bufferram;
        if (cached < 0)
                cached = 0;
 
index eb42c12..08be91e 100644 (file)
@@ -49,7 +49,7 @@ struct zone_padding {
 enum zone_stat_item {
        NR_FILE_MAPPED, /* mapped into pagetables.
                           only modified from process context */
-
+       NR_FILE_PAGES,
        NR_VM_ZONE_STAT_ITEMS };
 
 struct per_cpu_pages {
index 1245df7..0a2f5d2 100644 (file)
@@ -113,51 +113,6 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
 extern void remove_from_page_cache(struct page *page);
 extern void __remove_from_page_cache(struct page *page);
 
-extern atomic_t nr_pagecache;
-
-#ifdef CONFIG_SMP
-
-#define PAGECACHE_ACCT_THRESHOLD        max(16, NR_CPUS * 2)
-DECLARE_PER_CPU(long, nr_pagecache_local);
-
-/*
- * pagecache_acct implements approximate accounting for pagecache.
- * vm_enough_memory() do not need high accuracy. Writers will keep
- * an offset in their per-cpu arena and will spill that into the
- * global count whenever the absolute value of the local count
- * exceeds the counter's threshold.
- *
- * MUST be protected from preemption.
- * current protection is mapping->page_lock.
- */
-static inline void pagecache_acct(int count)
-{
-       long *local;
-
-       local = &__get_cpu_var(nr_pagecache_local);
-       *local += count;
-       if (*local > PAGECACHE_ACCT_THRESHOLD || *local < -PAGECACHE_ACCT_THRESHOLD) {
-               atomic_add(*local, &nr_pagecache);
-               *local = 0;
-       }
-}
-
-#else
-
-static inline void pagecache_acct(int count)
-{
-       atomic_add(count, &nr_pagecache);
-}
-#endif
-
-static inline unsigned long get_page_cache_size(void)
-{
-       int ret = atomic_read(&nr_pagecache);
-       if (unlikely(ret < 0))
-               ret = 0;
-       return ret;
-}
-
 /*
  * Return byte-offset into filesystem object for page.
  */
index 648f2c0..87d62c4 100644 (file)
@@ -120,7 +120,7 @@ void __remove_from_page_cache(struct page *page)
        radix_tree_delete(&mapping->page_tree, page->index);
        page->mapping = NULL;
        mapping->nrpages--;
-       pagecache_acct(-1);
+       __dec_zone_page_state(page, NR_FILE_PAGES);
 }
 
 void remove_from_page_cache(struct page *page)
@@ -449,7 +449,7 @@ int add_to_page_cache(struct page *page, struct address_space *mapping,
                        page->mapping = mapping;
                        page->index = offset;
                        mapping->nrpages++;
-                       pagecache_acct(1);
+                       __inc_zone_page_state(page, NR_FILE_PAGES);
                }
                write_unlock_irq(&mapping->tree_lock);
                radix_tree_preload_end();
index 6446c61..c1868ec 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -96,7 +96,7 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
        if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) {
                unsigned long n;
 
-               free = get_page_cache_size();
+               free = global_page_state(NR_FILE_PAGES);
                free += nr_swap_pages;
 
                /*
index 029fada..5151c44 100644 (file)
@@ -1122,7 +1122,7 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
        if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) {
                unsigned long n;
 
-               free = get_page_cache_size();
+               free = global_page_state(NR_FILE_PAGES);
                free += nr_swap_pages;
 
                /*
index 04dd2b0..8350720 100644 (file)
@@ -2124,16 +2124,11 @@ static int page_alloc_cpu_notify(struct notifier_block *self,
                                 unsigned long action, void *hcpu)
 {
        int cpu = (unsigned long)hcpu;
-       long *count;
        unsigned long *src, *dest;
 
        if (action == CPU_DEAD) {
                int i;
 
-               /* Drain local pagecache count. */
-               count = &per_cpu(nr_pagecache_local, cpu);
-               atomic_add(*count, &nr_pagecache);
-               *count = 0;
                local_irq_disable();
                __drain_pages(cpu);
 
index 7535211..fccbd9b 100644 (file)
@@ -87,7 +87,7 @@ static int __add_to_swap_cache(struct page *page, swp_entry_t entry,
                        SetPageSwapCache(page);
                        set_page_private(page, entry.val);
                        total_swapcache_pages++;
-                       pagecache_acct(1);
+                       __inc_zone_page_state(page, NR_FILE_PAGES);
                }
                write_unlock_irq(&swapper_space.tree_lock);
                radix_tree_preload_end();
@@ -132,7 +132,7 @@ void __delete_from_swap_cache(struct page *page)
        set_page_private(page, 0);
        ClearPageSwapCache(page);
        total_swapcache_pages--;
-       pagecache_acct(-1);
+       __dec_zone_page_state(page, NR_FILE_PAGES);
        INC_CACHE_INFO(del_total);
 }
 
index 4800091..f16b33e 100644 (file)
  */
 DEFINE_PER_CPU(struct page_state, page_states) = {0};
 
-atomic_t nr_pagecache = ATOMIC_INIT(0);
-EXPORT_SYMBOL(nr_pagecache);
-#ifdef CONFIG_SMP
-DEFINE_PER_CPU(long, nr_pagecache_local) = 0;
-#endif
-
 static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
 {
        unsigned cpu;
@@ -402,6 +396,7 @@ struct seq_operations fragmentation_op = {
 static char *vmstat_text[] = {
        /* Zoned VM counters */
        "nr_mapped",
+       "nr_file_pages",
 
        /* Page state */
        "nr_dirty",