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authorChristoph Lameter <clameter@sgi.com>2006-06-30 04:55:35 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-30 14:25:34 -0400
commit347ce434d57da80fd5809c0c836f206a50999c26 (patch)
treef730d151be77977f594e5cc083a93bbeb4c602cc /include
parent65ba55f500a37272985d071c9bbb35256a2f7c14 (diff)
[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>
Diffstat (limited to 'include')
-rw-r--r--include/linux/mmzone.h2
-rw-r--r--include/linux/pagemap.h45
2 files changed, 1 insertions, 46 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index eb42c1277023..08be91e6cecf 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -49,7 +49,7 @@ struct zone_padding {
49enum zone_stat_item { 49enum zone_stat_item {
50 NR_FILE_MAPPED, /* mapped into pagetables. 50 NR_FILE_MAPPED, /* mapped into pagetables.
51 only modified from process context */ 51 only modified from process context */
52 52 NR_FILE_PAGES,
53 NR_VM_ZONE_STAT_ITEMS }; 53 NR_VM_ZONE_STAT_ITEMS };
54 54
55struct per_cpu_pages { 55struct per_cpu_pages {
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 1245df7141aa..0a2f5d27f60e 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -113,51 +113,6 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
113extern void remove_from_page_cache(struct page *page); 113extern void remove_from_page_cache(struct page *page);
114extern void __remove_from_page_cache(struct page *page); 114extern void __remove_from_page_cache(struct page *page);
115 115
116extern atomic_t nr_pagecache;
117
118#ifdef CONFIG_SMP
119
120#define PAGECACHE_ACCT_THRESHOLD max(16, NR_CPUS * 2)
121DECLARE_PER_CPU(long, nr_pagecache_local);
122
123/*
124 * pagecache_acct implements approximate accounting for pagecache.
125 * vm_enough_memory() do not need high accuracy. Writers will keep
126 * an offset in their per-cpu arena and will spill that into the
127 * global count whenever the absolute value of the local count
128 * exceeds the counter's threshold.
129 *
130 * MUST be protected from preemption.
131 * current protection is mapping->page_lock.
132 */
133static inline void pagecache_acct(int count)
134{
135 long *local;
136
137 local = &__get_cpu_var(nr_pagecache_local);
138 *local += count;
139 if (*local > PAGECACHE_ACCT_THRESHOLD || *local < -PAGECACHE_ACCT_THRESHOLD) {
140 atomic_add(*local, &nr_pagecache);
141 *local = 0;
142 }
143}
144
145#else
146
147static inline void pagecache_acct(int count)
148{
149 atomic_add(count, &nr_pagecache);
150}
151#endif
152
153static inline unsigned long get_page_cache_size(void)
154{
155 int ret = atomic_read(&nr_pagecache);
156 if (unlikely(ret < 0))
157 ret = 0;
158 return ret;
159}
160
161/* 116/*
162 * Return byte-offset into filesystem object for page. 117 * Return byte-offset into filesystem object for page.
163 */ 118 */