[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>

12 files changed, 16 insertions, 17 deletions

diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c
index 0bb1e5c13442..aa211dcddb08 100644
--- a/arch/i386/mm/pgtable.c
+++ b/arch/i386/mm/pgtable.c
@@ -59,7 +59,7 @@ void show_mem(void)
         printk(KERN_INFO "%d pages swap cached\n", cached);
 
         get_page_state(&ps);
-        printk(KERN_INFO "%lu pages dirty\n", ps.nr_dirty);
+        printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_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", global_page_state(NR_SLAB));
diff --git a/drivers/base/node.c b/drivers/base/node.c
index c22fb67ec50c..6fed520d00f4 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -50,8 +50,6 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
         __get_zone_counts(&active, &inactive, &free, NODE_DATA(nid));
 
         /* 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;
 
@@ -81,7 +79,7 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                        nid, K(i.freehigh),
                        nid, K(i.totalram - i.totalhigh),
                        nid, K(i.freeram - i.freehigh),
-                       nid, K(ps.nr_dirty),
+                       nid, K(node_page_state(nid, NR_FILE_DIRTY)),
                        nid, K(ps.nr_writeback),
                        nid, K(node_page_state(nid, NR_FILE_PAGES)),
                        nid, K(node_page_state(nid, NR_FILE_MAPPED)),
diff --git a/fs/buffer.c b/fs/buffer.c
index e9994722f4a3..90e52e677209 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -852,7 +852,7 @@ int __set_page_dirty_buffers(struct page *page)
                 write_lock_irq(&mapping->tree_lock);
                 if (page->mapping) {    /* Race with truncate? */
                         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);
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 031b27a4bc9a..e5ad10756848 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -464,7 +464,7 @@ void sync_inodes_sb(struct super_block *sb, int wait)
                 .range_start    = 0,
                 .range_end      = LLONG_MAX,
         };
-        unsigned long nr_dirty = read_page_state(nr_dirty);
+        unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
         unsigned long nr_unstable = read_page_state(nr_unstable);
 
         wbc.nr_to_write = nr_dirty + nr_unstable +
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index d89f6fb3b3a3..26b1fe909377 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -315,6 +315,7 @@ nfs_scan_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst,
                                                 req->wb_index, NFS_PAGE_TAG_DIRTY);
                                 nfs_list_remove_request(req);
                                 nfs_list_add_request(req, dst);
+                                dec_zone_page_state(req->wb_page, NR_FILE_DIRTY);
                                 res++;
                         }
                 }
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 8fccb9cb173b..a6d1ca513dde 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -497,7 +497,7 @@ nfs_mark_request_dirty(struct nfs_page *req)
         nfs_list_add_request(req, &nfsi->dirty);
         nfsi->ndirty++;
         spin_unlock(&nfsi->req_lock);
-        inc_page_state(nr_dirty);
+        inc_zone_page_state(req->wb_page, NR_FILE_DIRTY);
         mark_inode_dirty(inode);
 }
 
@@ -609,7 +609,6 @@ nfs_scan_dirty(struct inode *inode, struct list_head *dst, unsigned long idx_sta
         if (nfsi->ndirty != 0) {
                 res = nfs_scan_lock_dirty(nfsi, dst, idx_start, npages);
                 nfsi->ndirty -= res;
-                sub_page_state(nr_dirty,res);
                 if ((nfsi->ndirty == 0) != list_empty(&nfsi->dirty))
                         printk(KERN_ERR "NFS: desynchronized value of nfs_i.ndirty.\n");
         }
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index 0eae68f84210..e23717dec3c1 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -190,7 +190,7 @@ static int meminfo_read_proc(char *page, char **start, off_t off,
                 K(i.freeram-i.freehigh),
                 K(i.totalswap),
                 K(i.freeswap),
-                K(ps.nr_dirty),
+                K(global_page_state(NR_FILE_DIRTY)),
                 K(ps.nr_writeback),
                 K(global_page_state(NR_ANON_PAGES)),
                 K(global_page_state(NR_FILE_MAPPED)),
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 15adb435f240..1cc8412ac264 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -53,6 +53,7 @@ enum zone_stat_item {
         NR_FILE_PAGES,
         NR_SLAB,        /* Pages used by slab allocator */
         NR_PAGETABLE,   /* used for pagetables */
+        NR_FILE_DIRTY,
         NR_VM_ZONE_STAT_ITEMS };
 
 struct per_cpu_pages {
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 56220441d7c9..b323ea2c6260 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -22,7 +22,6 @@
  * commented here.
  */
 struct page_state {
-        unsigned long nr_dirty;         /* Dirty writeable pages */
         unsigned long nr_writeback;     /* Pages under writeback */
         unsigned long nr_unstable;      /* NFS unstable pages */
 #define GET_PAGE_STATE_LAST nr_unstable
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",