[PATCH] zoned vm counters: conversion of nr_pagecache to per zone counter
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>
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index eb42c12..08be91e 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -49,7 +49,7 @@
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 {
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 1245df7..0a2f5d2 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -113,51 +113,6 @@
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.
*/