Conversion of nr_mapped to a per zone counter nr_mapped is important because it allows a determination how many pages of a zone are not mapped, which would allow a more efficient means of determining when we need to reclaim memory in a zone. We take the nr_mapped field out of the page state structure and define a new per zone counter named NR_MAPPED. We replace the use of nr_mapped in various kernel locations. This avoids the looping over all processors in try_to_free_pages(), writeback, reclaim (swap + zone reclaim). Signed-off-by: Christoph Lameter Index: linux-2.6.17-rc6-mm1/drivers/base/node.c =================================================================== --- linux-2.6.17-rc6-mm1.orig/drivers/base/node.c 2006-06-08 15:20:05.426540998 -0700 +++ linux-2.6.17-rc6-mm1/drivers/base/node.c 2006-06-08 15:44:58.889749567 -0700 @@ -44,18 +44,18 @@ static ssize_t node_read_meminfo(struct unsigned long inactive; unsigned long active; unsigned long free; + unsigned long nr_mapped; si_meminfo_node(&i, nid); get_page_state_node(&ps, nid); __get_zone_counts(&active, &inactive, &free, NODE_DATA(nid)); + nr_mapped = node_page_state(nid, NR_MAPPED); /* Check for negative values in these approximate counters */ if ((long)ps.nr_dirty < 0) ps.nr_dirty = 0; if ((long)ps.nr_writeback < 0) ps.nr_writeback = 0; - if ((long)ps.nr_mapped < 0) - ps.nr_mapped = 0; if ((long)ps.nr_slab < 0) ps.nr_slab = 0; @@ -84,7 +84,7 @@ 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(ps.nr_mapped), + nid, K(nr_mapped), nid, K(ps.nr_slab)); n += hugetlb_report_node_meminfo(nid, buf + n); return n; Index: linux-2.6.17-rc6-mm1/fs/proc/proc_misc.c =================================================================== --- linux-2.6.17-rc6-mm1.orig/fs/proc/proc_misc.c 2006-06-08 15:20:08.334564156 -0700 +++ linux-2.6.17-rc6-mm1/fs/proc/proc_misc.c 2006-06-08 15:44:58.890726069 -0700 @@ -190,7 +190,7 @@ static int meminfo_read_proc(char *page, K(i.freeswap), K(ps.nr_dirty), K(ps.nr_writeback), - K(ps.nr_mapped), + K(global_page_state(NR_MAPPED)), K(ps.nr_slab), K(allowed), K(committed), Index: linux-2.6.17-rc6-mm1/mm/vmscan.c =================================================================== --- linux-2.6.17-rc6-mm1.orig/mm/vmscan.c 2006-06-08 15:20:11.595104562 -0700 +++ linux-2.6.17-rc6-mm1/mm/vmscan.c 2006-06-08 15:44:58.891702571 -0700 @@ -997,7 +997,7 @@ unsigned long try_to_free_pages(struct z } for (priority = DEF_PRIORITY; priority >= 0; priority--) { - sc.nr_mapped = read_page_state(nr_mapped); + sc.nr_mapped = global_page_state(NR_MAPPED); sc.nr_scanned = 0; if (!priority) disable_swap_token(); @@ -1082,7 +1082,7 @@ loop_again: total_scanned = 0; nr_reclaimed = 0; sc.may_writepage = !laptop_mode, - sc.nr_mapped = read_page_state(nr_mapped); + sc.nr_mapped = global_page_state(NR_MAPPED); inc_page_state(pageoutrun); @@ -1417,7 +1417,7 @@ unsigned long shrink_all_memory(unsigned for (prio = DEF_PRIORITY; prio >= 0; prio--) { unsigned long nr_to_scan = nr_pages - ret; - sc.nr_mapped = read_page_state(nr_mapped); + sc.nr_mapped = global_page_state(NR_MAPPED); sc.nr_scanned = 0; ret += shrink_all_zones(nr_to_scan, prio, pass, &sc); @@ -1559,7 +1559,7 @@ static int __zone_reclaim(struct zone *z struct scan_control sc = { .may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE), .may_swap = !!(zone_reclaim_mode & RECLAIM_SWAP), - .nr_mapped = read_page_state(nr_mapped), + .nr_mapped = global_page_state(NR_MAPPED), .swap_cluster_max = max_t(unsigned long, nr_pages, SWAP_CLUSTER_MAX), .gfp_mask = gfp_mask, Index: linux-2.6.17-rc6-mm1/mm/page-writeback.c =================================================================== --- linux-2.6.17-rc6-mm1.orig/mm/page-writeback.c 2006-06-08 15:20:11.553114973 -0700 +++ linux-2.6.17-rc6-mm1/mm/page-writeback.c 2006-06-08 15:44:58.892679074 -0700 @@ -111,7 +111,7 @@ static void get_writeback_state(struct w { wbs->nr_dirty = read_page_state(nr_dirty); wbs->nr_unstable = read_page_state(nr_unstable); - wbs->nr_mapped = read_page_state(nr_mapped); + wbs->nr_mapped = global_page_state(NR_MAPPED); wbs->nr_writeback = read_page_state(nr_writeback); } Index: linux-2.6.17-rc6-mm1/mm/page_alloc.c =================================================================== --- linux-2.6.17-rc6-mm1.orig/mm/page_alloc.c 2006-06-08 15:44:55.859663761 -0700 +++ linux-2.6.17-rc6-mm1/mm/page_alloc.c 2006-06-08 15:44:58.893655576 -0700 @@ -1815,7 +1815,7 @@ void show_free_areas(void) ps.nr_unstable, nr_free_pages(), ps.nr_slab, - ps.nr_mapped, + global_page_state(NR_MAPPED), ps.nr_page_table_pages); for_each_zone(zone) { @@ -2801,13 +2801,13 @@ struct seq_operations zoneinfo_op = { static char *vmstat_text[] = { /* Zoned VM counters */ + "nr_mapped", /* Page state */ "nr_dirty", "nr_writeback", "nr_unstable", "nr_page_table_pages", - "nr_mapped", "nr_slab", "pgpgin", Index: linux-2.6.17-rc6-mm1/mm/rmap.c =================================================================== --- linux-2.6.17-rc6-mm1.orig/mm/rmap.c 2006-06-08 15:20:11.579480529 -0700 +++ linux-2.6.17-rc6-mm1/mm/rmap.c 2006-06-08 15:44:58.894632078 -0700 @@ -455,7 +455,7 @@ static void __page_set_anon_rmap(struct * nr_mapped state can be updated without turning off * interrupts because it is not modified via interrupt. */ - __inc_page_state(nr_mapped); + __inc_zone_page_state(page, NR_MAPPED); } /** @@ -499,7 +499,7 @@ void page_add_new_anon_rmap(struct page void page_add_file_rmap(struct page *page) { if (atomic_inc_and_test(&page->_mapcount)) - __inc_page_state(nr_mapped); + __inc_zone_page_state(page, NR_MAPPED); } /** @@ -531,7 +531,7 @@ void page_remove_rmap(struct page *page) */ if (page_test_and_clear_dirty(page)) set_page_dirty(page); - __dec_page_state(nr_mapped); + __dec_zone_page_state(page, NR_MAPPED); } } Index: linux-2.6.17-rc6-mm1/include/linux/mmzone.h =================================================================== --- linux-2.6.17-rc6-mm1.orig/include/linux/mmzone.h 2006-06-08 15:42:25.204930191 -0700 +++ linux-2.6.17-rc6-mm1/include/linux/mmzone.h 2006-06-08 15:44:58.895608580 -0700 @@ -47,6 +47,9 @@ struct zone_padding { #endif enum zone_stat_item { + NR_MAPPED, /* mapped into pagetables. + only modified from process context */ + NR_STAT_ITEMS }; #ifdef CONFIG_SMP Index: linux-2.6.17-rc6-mm1/include/linux/page-flags.h =================================================================== --- linux-2.6.17-rc6-mm1.orig/include/linux/page-flags.h 2006-06-08 15:42:25.205906693 -0700 +++ linux-2.6.17-rc6-mm1/include/linux/page-flags.h 2006-06-08 15:44:58.896585082 -0700 @@ -123,8 +123,6 @@ struct page_state { unsigned long nr_writeback; /* Pages under writeback */ unsigned long nr_unstable; /* NFS unstable pages */ unsigned long nr_page_table_pages;/* Pages used for pagetables */ - unsigned long nr_mapped; /* mapped into pagetables. - * only modified from process context */ unsigned long nr_slab; /* In slab */ #define GET_PAGE_STATE_LAST nr_slab Index: linux-2.6.17-rc6-mm1/mm/swap_prefetch.c =================================================================== --- linux-2.6.17-rc6-mm1.orig/mm/swap_prefetch.c 2006-06-08 15:20:11.590222051 -0700 +++ linux-2.6.17-rc6-mm1/mm/swap_prefetch.c 2006-06-08 15:44:58.896585082 -0700 @@ -394,7 +394,7 @@ static int prefetch_suitable(void) * even if the slab is being allocated on a remote node. This * would be expensive to fix and not of great significance. */ - limit = ps.nr_mapped + ps.nr_slab + ps.nr_dirty + + limit = global_page_state(NR_MAPPED) + ps.nr_slab + ps.nr_dirty + ps.nr_unstable + total_swapcache_pages; if (limit > ns->prefetch_watermark) { node_clear(node, sp_stat.prefetch_nodes); Index: linux-2.6.17-rc6-mm1/arch/i386/mm/pgtable.c =================================================================== --- linux-2.6.17-rc6-mm1.orig/arch/i386/mm/pgtable.c 2006-06-05 17:57:02.000000000 -0700 +++ linux-2.6.17-rc6-mm1/arch/i386/mm/pgtable.c 2006-06-08 15:45:17.903220642 -0700 @@ -61,7 +61,7 @@ void show_mem(void) get_page_state(&ps); printk(KERN_INFO "%lu pages dirty\n", ps.nr_dirty); printk(KERN_INFO "%lu pages writeback\n", ps.nr_writeback); - printk(KERN_INFO "%lu pages mapped\n", ps.nr_mapped); + printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_MAPPED)); printk(KERN_INFO "%lu pages slab\n", ps.nr_slab); printk(KERN_INFO "%lu pages pagetables\n", ps.nr_page_table_pages); }