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

Conversion of nr_unstable to a per zone counter

We need to do some special modifications to the nfs code since there are
multiple cases of disposition and we need to have a page ref for proper
accounting.

This converts the last critical page state of the VM and therefore we need to
remove several functions that were depending on GET_PAGE_STATE_LAST in order
to make the kernel compile again.  We are only left with event type counters
in page state.

[akpm@osdl.org: bugfixes]
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>

9 files changed, 11 insertions, 46 deletions

diff --git a/drivers/base/node.c b/drivers/base/node.c
index a7b3dcbbdfc9..b73d869c9d48 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -40,13 +40,11 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
         int n;
         int nid = dev->id;
         struct sysinfo i;
-        struct page_state ps;
         unsigned long inactive;
         unsigned long active;
         unsigned long free;
 
         si_meminfo_node(&i, nid);
-        get_page_state_node(&ps, nid);
         __get_zone_counts(&active, &inactive, &free, NODE_DATA(nid));
 
 
@@ -66,6 +64,7 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                        "Node %d Mapped:       %8lu kB\n"
                        "Node %d AnonPages:    %8lu kB\n"
                        "Node %d PageTables:   %8lu kB\n"
+                       "Node %d NFS Unstable: %8lu kB\n"
                        "Node %d Slab:         %8lu kB\n",
                        nid, K(i.totalram),
                        nid, K(i.freeram),
@@ -82,6 +81,7 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                        nid, K(node_page_state(nid, NR_FILE_MAPPED)),
                        nid, K(node_page_state(nid, NR_ANON_PAGES)),
                        nid, K(node_page_state(nid, NR_PAGETABLE)),
+                       nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
                        nid, K(node_page_state(nid, NR_SLAB)));
         n += hugetlb_report_node_meminfo(nid, buf + n);
         return n;
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index e5ad10756848..892643dc9af1 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -465,7 +465,7 @@ void sync_inodes_sb(struct super_block *sb, int wait)
                 .range_end      = LLONG_MAX,
         };
         unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
-        unsigned long nr_unstable = read_page_state(nr_unstable);
+        unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
 
         wbc.nr_to_write = nr_dirty + nr_unstable +
                         (inodes_stat.nr_inodes - inodes_stat.nr_unused) +
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index a6d1ca513dde..f21e268705c0 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -525,7 +525,7 @@ nfs_mark_request_commit(struct nfs_page *req)
         nfs_list_add_request(req, &nfsi->commit);
         nfsi->ncommit++;
         spin_unlock(&nfsi->req_lock);
-        inc_page_state(nr_unstable);
+        inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
         mark_inode_dirty(inode);
 }
 #endif
@@ -1393,7 +1393,6 @@ static void nfs_commit_done(struct rpc_task *task, void *calldata)
 {
         struct nfs_write_data   *data = calldata;
         struct nfs_page         *req;
-        int res = 0;
 
         dprintk("NFS: %4d nfs_commit_done (status %d)\n",
                                 task->tk_pid, task->tk_status);
@@ -1405,6 +1404,7 @@ static void nfs_commit_done(struct rpc_task *task, void *calldata)
         while (!list_empty(&data->pages)) {
                 req = nfs_list_entry(data->pages.next);
                 nfs_list_remove_request(req);
+                dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
 
                 dprintk("NFS: commit (%s/%Ld %d@%Ld)",
                         req->wb_context->dentry->d_inode->i_sb->s_id,
@@ -1431,9 +1431,7 @@ static void nfs_commit_done(struct rpc_task *task, void *calldata)
                 nfs_mark_request_dirty(req);
         next:
                 nfs_clear_page_writeback(req);
-                res++;
         }
-        sub_page_state(nr_unstable,res);
 }
 
 static const struct rpc_call_ops nfs_commit_ops = {
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index 48cb35862445..eae66b41a1a4 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -120,7 +120,6 @@ static int meminfo_read_proc(char *page, char **start, off_t off,
 {
         struct sysinfo i;
         int len;
-        struct page_state ps;
         unsigned long inactive;
         unsigned long active;
         unsigned long free;
@@ -129,7 +128,6 @@ static int meminfo_read_proc(char *page, char **start, off_t off,
         struct vmalloc_info vmi;
         long cached;
 
-        get_page_state(&ps);
         get_zone_counts(&active, &inactive, &free);
 
 /*
@@ -172,6 +170,7 @@ static int meminfo_read_proc(char *page, char **start, off_t off,
                 "Mapped:       %8lu kB\n"
                 "Slab:         %8lu kB\n"
                 "PageTables:   %8lu kB\n"
+                "NFS Unstable: %8lu kB\n"
                 "CommitLimit:  %8lu kB\n"
                 "Committed_AS: %8lu kB\n"
                 "VmallocTotal: %8lu kB\n"
@@ -196,6 +195,7 @@ static int meminfo_read_proc(char *page, char **start, off_t off,
                 K(global_page_state(NR_FILE_MAPPED)),
                 K(global_page_state(NR_SLAB)),
                 K(global_page_state(NR_PAGETABLE)),
+                K(global_page_state(NR_UNSTABLE_NFS)),
                 K(allowed),
                 K(committed),
                 (unsigned long)VMALLOC_TOTAL >> 10,
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 885cc9727001..e9d80697f555 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -55,6 +55,7 @@ enum zone_stat_item {
         NR_PAGETABLE,   /* used for pagetables */
         NR_FILE_DIRTY,
         NR_WRITEBACK,
+        NR_UNSTABLE_NFS,        /* NFS unstable pages */
         NR_VM_ZONE_STAT_ITEMS };
 
 struct per_cpu_pages {
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 60c2e0382ceb..9de2a41c885c 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -22,13 +22,6 @@
  * commented here.
  */
 struct page_state {
-        unsigned long nr_unstable;      /* NFS unstable pages */
-#define GET_PAGE_STATE_LAST nr_unstable
-
-        /*
-         * The below are zeroed by get_page_state().  Use get_full_page_state()
-         * to add up all these.
-         */
         unsigned long pgpgin;           /* Disk reads */
         unsigned long pgpgout;          /* Disk writes */
         unsigned long pswpin;           /* swap reads */
@@ -77,8 +70,6 @@ struct page_state {
         unsigned long nr_bounce;        /* pages for bounce buffers */
 };
 
-extern void get_page_state(struct page_state *ret);
-extern void get_page_state_node(struct page_state *ret, int node);
 extern void get_full_page_state(struct page_state *ret);
 extern unsigned long read_page_state_offset(unsigned long offset);
 extern void mod_page_state_offset(unsigned long offset, unsigned long delta);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 3cfdff4b1985..de9836f43db5 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -110,7 +110,7 @@ struct writeback_state
 static void get_writeback_state(struct writeback_state *wbs)
 {
         wbs->nr_dirty = global_page_state(NR_FILE_DIRTY);
-        wbs->nr_unstable = read_page_state(nr_unstable);
+        wbs->nr_unstable = global_page_state(NR_UNSTABLE_NFS);
         wbs->nr_mapped = global_page_state(NR_FILE_MAPPED) +
                                 global_page_state(NR_ANON_PAGES);
         wbs->nr_writeback = global_page_state(NR_WRITEBACK);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a12e894a8bca..6aa2c31f513b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1271,7 +1271,6 @@ void si_meminfo_node(struct sysinfo *val, int nid)
  */
 void show_free_areas(void)
 {
-        struct page_state ps;
         int cpu, temperature;
         unsigned long active;
         unsigned long inactive;
@@ -1303,7 +1302,6 @@ void show_free_areas(void)
                 }
         }
 
-        get_page_state(&ps);
         get_zone_counts(&active, &inactive, &free);
 
         printk("Free pages: %11ukB (%ukB HighMem)\n",
@@ -1316,7 +1314,7 @@ void show_free_areas(void)
                 inactive,
                 global_page_state(NR_FILE_DIRTY),
                 global_page_state(NR_WRITEBACK),
-                ps.nr_unstable,
+                global_page_state(NR_UNSTABLE_NFS),
                 nr_free_pages(),
                 global_page_state(NR_SLAB),
                 global_page_state(NR_FILE_MAPPED),
diff --git a/mm/vmstat.c b/mm/vmstat.c
index e84c7e520a1d..9dc270aed5c4 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -45,28 +45,6 @@ static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
         }
 }
 
-void get_page_state_node(struct page_state *ret, int node)
-{
-        int nr;
-        cpumask_t mask = node_to_cpumask(node);
-
-        nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
-        nr /= sizeof(unsigned long);
-
-        __get_page_state(ret, nr+1, &mask);
-}
-
-void get_page_state(struct page_state *ret)
-{
-        int nr;
-        cpumask_t mask = CPU_MASK_ALL;
-
-        nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
-        nr /= sizeof(unsigned long);
-
-        __get_page_state(ret, nr + 1, &mask);
-}
-
 void get_full_page_state(struct page_state *ret)
 {
         cpumask_t mask = CPU_MASK_ALL;
@@ -402,10 +380,9 @@ static char *vmstat_text[] = {
         "nr_page_table_pages",
         "nr_dirty",
         "nr_writeback",
-
-        /* Page state */
         "nr_unstable",
 
+        /* Event counters */
         "pgpgin",
         "pgpgout",
         "pswpin",