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

This makes nr_dirty a per zone counter.  Looping over all processors is
avoided during writeback state determination.

The counter aggregation for nr_dirty had to be undone in the NFS layer since
we summed up the page counts from multiple zones.  Someone more familiar with
NFS should probably review what I have done.

[akpm@osdl.org: bugfix]
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>

3 files changed, 8 insertions, 7 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 0faacfe18909..da8547830098 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -109,7 +109,7 @@ struct writeback_state
 
 static void get_writeback_state(struct writeback_state *wbs)
 {
-        wbs->nr_dirty = read_page_state(nr_dirty);
+        wbs->nr_dirty = global_page_state(NR_FILE_DIRTY);
         wbs->nr_unstable = read_page_state(nr_unstable);
         wbs->nr_mapped = global_page_state(NR_FILE_MAPPED) +
                                 global_page_state(NR_ANON_PAGES);
@@ -641,7 +641,8 @@ int __set_page_dirty_nobuffers(struct page *page)
                         if (mapping2) { /* Race with truncate? */
                                 BUG_ON(mapping2 != mapping);
                                 if (mapping_cap_account_dirty(mapping))
-                                        inc_page_state(nr_dirty);
+                                        __inc_zone_page_state(page,
+                                                                NR_FILE_DIRTY);
                                 radix_tree_tag_set(&mapping->page_tree,
                                         page_index(page), PAGECACHE_TAG_DIRTY);
                         }
@@ -728,9 +729,9 @@ int test_clear_page_dirty(struct page *page)
                         radix_tree_tag_clear(&mapping->page_tree,
                                                 page_index(page),
                                                 PAGECACHE_TAG_DIRTY);
-                        write_unlock_irqrestore(&mapping->tree_lock, flags);
                         if (mapping_cap_account_dirty(mapping))
-                                dec_page_state(nr_dirty);
+                                __dec_zone_page_state(page, NR_FILE_DIRTY);
+                        write_unlock_irqrestore(&mapping->tree_lock, flags);
                         return 1;
                 }
                 write_unlock_irqrestore(&mapping->tree_lock, flags);
@@ -761,7 +762,7 @@ int clear_page_dirty_for_io(struct page *page)
         if (mapping) {
                 if (TestClearPageDirty(page)) {
                         if (mapping_cap_account_dirty(mapping))
-                                dec_page_state(nr_dirty);
+                                dec_zone_page_state(page, NR_FILE_DIRTY);
                         return 1;
                 }
                 return 0;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index ed3f2a7b4071..c2b9aa4acc46 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1314,7 +1314,7 @@ void show_free_areas(void)
                 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
                 active,
                 inactive,
-                ps.nr_dirty,
+                global_page_state(NR_FILE_DIRTY),
                 ps.nr_writeback,
                 ps.nr_unstable,
                 nr_free_pages(),
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 292a35fe56c9..1982fb533a40 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -400,9 +400,9 @@ static char *vmstat_text[] = {
         "nr_file_pages",
         "nr_slab",
         "nr_page_table_pages",
+        "nr_dirty",
 
         /* Page state */
-        "nr_dirty",
         "nr_writeback",
         "nr_unstable",