From: Christoph Lameter nr_mapped is important because it allows a determination of 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_FILE_MAPPED (the anonymous pages will be split off from NR_MAPPED in the next patch). 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 Signed-off-by: Andrew Morton --- arch/i386/mm/pgtable.c | 2 +- drivers/base/node.c | 4 +--- fs/proc/proc_misc.c | 2 +- include/linux/mmzone.h | 3 +++ mm/page-writeback.c | 2 +- mm/page_alloc.c | 2 +- mm/rmap.c | 6 +++--- mm/vmscan.c | 6 +++--- mm/vmstat.c | 2 +- 9 files changed, 15 insertions(+), 14 deletions(-) diff -puN arch/i386/mm/pgtable.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter arch/i386/mm/pgtable.c --- a/arch/i386/mm/pgtable.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter +++ a/arch/i386/mm/pgtable.c @@ -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_FILE_MAPPED)); printk(KERN_INFO "%lu pages slab\n", ps.nr_slab); printk(KERN_INFO "%lu pages pagetables\n", ps.nr_page_table_pages); } diff -puN drivers/base/node.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter drivers/base/node.c --- a/drivers/base/node.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter +++ a/drivers/base/node.c @@ -54,8 +54,6 @@ static ssize_t node_read_meminfo(struct 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 +82,7 @@ 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(node_page_state(nid, NR_FILE_MAPPED)), nid, K(ps.nr_slab)); n += hugetlb_report_node_meminfo(nid, buf + n); return n; diff -puN fs/proc/proc_misc.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter fs/proc/proc_misc.c --- a/fs/proc/proc_misc.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter +++ a/fs/proc/proc_misc.c @@ -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_FILE_MAPPED)), K(ps.nr_slab), K(allowed), K(committed), diff -puN include/linux/mmzone.h~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter include/linux/mmzone.h --- a/include/linux/mmzone.h~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter +++ a/include/linux/mmzone.h @@ -47,6 +47,9 @@ struct zone_padding { #endif enum zone_stat_item { + NR_FILE_MAPPED, /* mapped into pagetables. + only modified from process context */ + NR_VM_ZONE_STAT_ITEMS }; struct per_cpu_pages { diff -puN mm/page_alloc.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter mm/page_alloc.c --- a/mm/page_alloc.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter +++ a/mm/page_alloc.c @@ -1319,7 +1319,7 @@ void show_free_areas(void) ps.nr_unstable, nr_free_pages(), ps.nr_slab, - ps.nr_mapped, + global_page_state(NR_FILE_MAPPED), ps.nr_page_table_pages); for_each_zone(zone) { diff -puN mm/page-writeback.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter mm/page-writeback.c --- a/mm/page-writeback.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter +++ a/mm/page-writeback.c @@ -112,7 +112,7 @@ 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_FILE_MAPPED); wbs->nr_writeback = read_page_state(nr_writeback); } diff -puN mm/rmap.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter mm/rmap.c --- a/mm/rmap.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter +++ a/mm/rmap.c @@ -523,7 +523,7 @@ 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_FILE_MAPPED); } /** @@ -567,7 +567,7 @@ 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_FILE_MAPPED); } /** @@ -599,7 +599,7 @@ 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_FILE_MAPPED); } } diff -puN mm/vmscan.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter mm/vmscan.c --- a/mm/vmscan.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter +++ a/mm/vmscan.c @@ -990,7 +990,7 @@ 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_FILE_MAPPED); sc.nr_scanned = 0; if (!priority) disable_swap_token(); @@ -1075,7 +1075,7 @@ 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_FILE_MAPPED); inc_page_state(pageoutrun); @@ -1549,7 +1549,7 @@ 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_FILE_MAPPED), .swap_cluster_max = max_t(unsigned long, nr_pages, SWAP_CLUSTER_MAX), .gfp_mask = gfp_mask, diff -puN mm/vmstat.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter mm/vmstat.c --- a/mm/vmstat.c~zoned-vm-counters-convert-nr_mapped-to-per-zone-counter +++ a/mm/vmstat.c @@ -463,13 +463,13 @@ struct seq_operations fragmentation_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", _