[PATCH] zoned vm counters: conversion of nr_slab to per zone counter

- Allows reclaim to access counter without looping over processor counts.

- Allows accurate statistics on how many pages are used in a zone by
  the slab. This may become useful to balance slab allocations over
  various zones.

[akpm@osdl.org: bugfix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

9 files changed, 10 insertions, 12 deletions

diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c
index f85f1a40e5c8..73ac3599a0ea 100644
--- a/arch/i386/mm/pgtable.c
+++ b/arch/i386/mm/pgtable.c
@@ -62,7 +62,7 @@ void show_mem(void)
         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", global_page_state(NR_FILE_MAPPED));
-        printk(KERN_INFO "%lu pages slab\n", ps.nr_slab);
+        printk(KERN_INFO "%lu pages slab\n", global_page_state(NR_SLAB));
         printk(KERN_INFO "%lu pages pagetables\n", ps.nr_page_table_pages);
 }
 
diff --git a/drivers/base/node.c b/drivers/base/node.c
index c3bf05158c6d..db116a8791c8 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -54,8 +54,6 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                 ps.nr_dirty = 0;
         if ((long)ps.nr_writeback < 0)
                 ps.nr_writeback = 0;
-        if ((long)ps.nr_slab < 0)
-                ps.nr_slab = 0;
 
         n = sprintf(buf, "\n"
                        "Node %d MemTotal:     %8lu kB\n"
@@ -87,7 +85,7 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                        nid, K(node_page_state(nid, NR_FILE_PAGES)),
                        nid, K(node_page_state(nid, NR_FILE_MAPPED)),
                        nid, K(node_page_state(nid, NR_ANON_PAGES)),
-                       nid, K(ps.nr_slab));
+                       nid, K(node_page_state(nid, NR_SLAB)));
         n += hugetlb_report_node_meminfo(nid, buf + n);
         return n;
 }
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index ff809656ce31..16aaf7187bb3 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -194,7 +194,7 @@ static int meminfo_read_proc(char *page, char **start, off_t off,
                 K(ps.nr_writeback),
                 K(global_page_state(NR_ANON_PAGES)),
                 K(global_page_state(NR_FILE_MAPPED)),
-                K(ps.nr_slab),
+                K(global_page_state(NR_SLAB)),
                 K(allowed),
                 K(committed),
                 K(ps.nr_page_table_pages),
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 839e9a04fd49..67e03fc8533e 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -51,6 +51,7 @@ enum zone_stat_item {
         NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
                            only modified from process context */
         NR_FILE_PAGES,
+        NR_SLAB,        /* Pages used by slab allocator */
         NR_VM_ZONE_STAT_ITEMS };
 
 struct per_cpu_pages {
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 8ab8229523e6..4b97381a2937 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -26,8 +26,7 @@ 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_slab;          /* In slab */
-#define GET_PAGE_STATE_LAST nr_slab
+#define GET_PAGE_STATE_LAST nr_page_table_pages
 
         /*
          * The below are zeroed by get_page_state().  Use get_full_page_state()
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8350720f98a8..a38a11cfb483 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1318,7 +1318,7 @@ void show_free_areas(void)
                 ps.nr_writeback,
                 ps.nr_unstable,
                 nr_free_pages(),
-                ps.nr_slab,
+                global_page_state(NR_SLAB),
                 global_page_state(NR_FILE_MAPPED),
                 ps.nr_page_table_pages);
 
diff --git a/mm/slab.c b/mm/slab.c
index 0c33820038cb..5dcfb9044801 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1507,7 +1507,7 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
         nr_pages = (1 << cachep->gfporder);
         if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
                 atomic_add(nr_pages, &slab_reclaim_pages);
-        add_page_state(nr_slab, nr_pages);
+        add_zone_page_state(page_zone(page), NR_SLAB, nr_pages);
         for (i = 0; i < nr_pages; i++)
                 __SetPageSlab(page + i);
         return page_address(page);
@@ -1522,12 +1522,12 @@ static void kmem_freepages(struct kmem_cache *cachep, void *addr)
         struct page *page = virt_to_page(addr);
         const unsigned long nr_freed = i;
 
+        sub_zone_page_state(page_zone(page), NR_SLAB, nr_freed);
         while (i--) {
                 BUG_ON(!PageSlab(page));
                 __ClearPageSlab(page);
                 page++;
         }
-        sub_page_state(nr_slab, nr_freed);
         if (current->reclaim_state)
                 current->reclaim_state->reclaimed_slab += nr_freed;
         free_pages((unsigned long)addr, cachep->gfporder);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 0960846d649f..d6942436ac97 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1362,7 +1362,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
         for_each_zone(zone)
                 lru_pages += zone->nr_active + zone->nr_inactive;
 
-        nr_slab = read_page_state(nr_slab);
+        nr_slab = global_page_state(NR_SLAB);
         /* If slab caches are huge, it's better to hit them first */
         while (nr_slab >= lru_pages) {
                 reclaim_state.reclaimed_slab = 0;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 3baf4dffa62a..dc9e69209223 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -398,13 +398,13 @@ static char *vmstat_text[] = {
         "nr_anon_pages",
         "nr_mapped",
         "nr_file_pages",
+        "nr_slab",
 
         /* Page state */
         "nr_dirty",
         "nr_writeback",
         "nr_unstable",
         "nr_page_table_pages",
-        "nr_slab",
 
         "pgpgin",
         "pgpgout",