Subject: zoned vm counters: conversion of nr_pagecache to per zone counter From: Christoph Lameter 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. Updates of the page cache counters are always performed with interrupts off. We can therefore use the __ variant here. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Index: linux-2.6.17-rc6-cl/arch/sparc64/kernel/sys_sunos32.c =================================================================== --- linux-2.6.17-rc6-cl.orig/arch/sparc64/kernel/sys_sunos32.c 2006-06-12 12:42:42.240680230 -0700 +++ linux-2.6.17-rc6-cl/arch/sparc64/kernel/sys_sunos32.c 2006-06-13 10:19:38.470745634 -0700 @@ -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_PAGECACHE); freepages >>= 1; freepages += nr_free_pages(); freepages += nr_swap_pages; Index: linux-2.6.17-rc6-cl/arch/sparc/kernel/sys_sunos.c =================================================================== --- linux-2.6.17-rc6-cl.orig/arch/sparc/kernel/sys_sunos.c 2006-06-12 12:42:42.249468748 -0700 +++ linux-2.6.17-rc6-cl/arch/sparc/kernel/sys_sunos.c 2006-06-13 10:19:38.471722136 -0700 @@ -196,7 +196,7 @@ asmlinkage int sunos_brk(unsigned long b * 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_PAGECACHE); freepages >>= 1; freepages += nr_free_pages(); freepages += nr_swap_pages; Index: linux-2.6.17-rc6-cl/fs/proc/proc_misc.c =================================================================== --- linux-2.6.17-rc6-cl.orig/fs/proc/proc_misc.c 2006-06-13 10:19:37.517679599 -0700 +++ linux-2.6.17-rc6-cl/fs/proc/proc_misc.c 2006-06-13 10:19:38.472698639 -0700 @@ -142,7 +142,8 @@ static int meminfo_read_proc(char *page, 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_PAGECACHE) - + total_swapcache_pages - i.bufferram; if (cached < 0) cached = 0; Index: linux-2.6.17-rc6-cl/include/linux/pagemap.h =================================================================== --- linux-2.6.17-rc6-cl.orig/include/linux/pagemap.h 2006-06-12 12:42:50.853428498 -0700 +++ linux-2.6.17-rc6-cl/include/linux/pagemap.h 2006-06-13 10:19:38.473675141 -0700 @@ -115,51 +115,6 @@ int add_to_page_cache_lru(struct page *p 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: linux-2.6.17-rc6-cl/mm/filemap.c =================================================================== --- linux-2.6.17-rc6-cl.orig/mm/filemap.c 2006-06-12 12:42:52.024254482 -0700 +++ linux-2.6.17-rc6-cl/mm/filemap.c 2006-06-13 10:19:38.475628145 -0700 @@ -126,7 +126,7 @@ void __remove_from_page_cache(struct pag radix_tree_delete(&mapping->page_tree, page->index); page->mapping = NULL; mapping->nrpages--; - pagecache_acct(-1); + __dec_zone_page_state(page, NR_PAGECACHE); } EXPORT_SYMBOL(__remove_from_page_cache); @@ -424,7 +424,7 @@ int add_to_page_cache(struct page *page, page->mapping = mapping; page->index = offset; mapping->nrpages++; - pagecache_acct(1); + __inc_zone_page_state(page, NR_PAGECACHE); } write_unlock_irq(&mapping->tree_lock); radix_tree_preload_end(); Index: linux-2.6.17-rc6-cl/mm/mmap.c =================================================================== --- linux-2.6.17-rc6-cl.orig/mm/mmap.c 2006-06-12 12:42:52.037925511 -0700 +++ linux-2.6.17-rc6-cl/mm/mmap.c 2006-06-13 10:19:38.476604647 -0700 @@ -96,7 +96,7 @@ int __vm_enough_memory(long pages, int c if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { unsigned long n; - free = get_page_cache_size(); + free = global_page_state(NR_PAGECACHE); free += nr_swap_pages; /* Index: linux-2.6.17-rc6-cl/mm/nommu.c =================================================================== --- linux-2.6.17-rc6-cl.orig/mm/nommu.c 2006-06-05 17:57:02.000000000 -0700 +++ linux-2.6.17-rc6-cl/mm/nommu.c 2006-06-13 10:19:38.476604647 -0700 @@ -1122,7 +1122,7 @@ int __vm_enough_memory(long pages, int c if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { unsigned long n; - free = get_page_cache_size(); + free = global_page_state(NR_PAGECACHE); free += nr_swap_pages; /* Index: linux-2.6.17-rc6-cl/mm/page_alloc.c =================================================================== --- linux-2.6.17-rc6-cl.orig/mm/page_alloc.c 2006-06-13 10:19:37.520609105 -0700 +++ linux-2.6.17-rc6-cl/mm/page_alloc.c 2006-06-13 10:19:38.478557651 -0700 @@ -2231,16 +2231,11 @@ static int page_alloc_cpu_notify(struct 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: linux-2.6.17-rc6-cl/mm/swap_state.c =================================================================== --- linux-2.6.17-rc6-cl.orig/mm/swap_state.c 2006-06-12 12:42:52.062338063 -0700 +++ linux-2.6.17-rc6-cl/mm/swap_state.c 2006-06-13 10:19:38.479534153 -0700 @@ -89,7 +89,7 @@ static int __add_to_swap_cache(struct pa SetPageSwapCache(page); set_page_private(page, entry.val); total_swapcache_pages++; - pagecache_acct(1); + __inc_zone_page_state(page, NR_PAGECACHE); } write_unlock_irq(&swapper_space.tree_lock); radix_tree_preload_end(); @@ -135,7 +135,7 @@ void __delete_from_swap_cache(struct pag set_page_private(page, 0); ClearPageSwapCache(page); total_swapcache_pages--; - pagecache_acct(-1); + __dec_zone_page_state(page, NR_PAGECACHE); INC_CACHE_INFO(del_total); } Index: linux-2.6.17-rc6-cl/include/linux/mmzone.h =================================================================== --- linux-2.6.17-rc6-cl.orig/include/linux/mmzone.h 2006-06-13 10:19:37.518656101 -0700 +++ linux-2.6.17-rc6-cl/include/linux/mmzone.h 2006-06-13 10:19:38.479534153 -0700 @@ -49,7 +49,7 @@ struct zone_padding { enum zone_stat_item { NR_MAPPED, /* mapped into pagetables. only modified from process context */ - + NR_PAGECACHE, NR_VM_ZONE_STAT_ITEMS }; struct per_cpu_pages { Index: linux-2.6.17-rc6-cl/arch/s390/appldata/appldata_mem.c =================================================================== --- linux-2.6.17-rc6-cl.orig/arch/s390/appldata/appldata_mem.c 2006-06-12 12:42:42.183066607 -0700 +++ linux-2.6.17-rc6-cl/arch/s390/appldata/appldata_mem.c 2006-06-13 10:19:38.480510655 -0700 @@ -130,7 +130,8 @@ static void appldata_get_mem_data(void * 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_PAGECACHE) + - val.bufferram); si_swapinfo(&val); mem_data->totalswap = P2K(val.totalswap); Index: linux-2.6.17-rc6-cl/drivers/base/node.c =================================================================== --- linux-2.6.17-rc6-cl.orig/drivers/base/node.c 2006-06-13 10:19:37.516703097 -0700 +++ linux-2.6.17-rc6-cl/drivers/base/node.c 2006-06-13 10:19:38.481487157 -0700 @@ -69,6 +69,7 @@ static ssize_t node_read_meminfo(struct "Node %d LowFree: %8lu kB\n" "Node %d Dirty: %8lu kB\n" "Node %d Writeback: %8lu kB\n" + "Node %d PageCache: %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 nid, K(i.freeram - i.freehigh), nid, K(ps.nr_dirty), nid, K(ps.nr_writeback), + nid, K(node_page_state(nid, NR_PAGECACHE)), nid, K(node_page_state(nid, NR_MAPPED)), nid, K(ps.nr_slab)); n += hugetlb_report_node_meminfo(nid, buf + n); Index: linux-2.6.17-rc6-cl/mm/vmstat.c =================================================================== --- linux-2.6.17-rc6-cl.orig/mm/vmstat.c 2006-06-13 10:19:37.523538611 -0700 +++ linux-2.6.17-rc6-cl/mm/vmstat.c 2006-06-13 10:44:03.861517159 -0700 @@ -20,12 +20,6 @@ */ static 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; @@ -464,6 +458,7 @@ struct seq_operations fragmentation_op = static char *vmstat_text[] = { /* Zoned VM counters */ "nr_mapped", + "nr_pagecache", /* Page state */ "nr_dirty",