[PATCH] VM: add page_state info to per-node meminfo

Add page_state info to the per-node meminfo file in sysfs.  This is mostly
just for informational purposes.

The lack of this information was brought up recently during a discussion
regarding pagecache clearing, and I put this patch together to test out one
of the suggestions.

It seems like interesting info to have, so I'm submitting the patch.

Signed-off-by: Martin Hicks <mort@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 22 insertions, 2 deletions

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 904b27caf697..16c513aa4d48 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -39,13 +39,25 @@ 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));
 
+        /* 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;
+        if ((long)ps.nr_mapped < 0)
+                ps.nr_mapped = 0;
+        if ((long)ps.nr_slab < 0)
+                ps.nr_slab = 0;
+
         n = sprintf(buf, "\n"
                        "Node %d MemTotal:     %8lu kB\n"
                        "Node %d MemFree:      %8lu kB\n"
@@ -55,7 +67,11 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                        "Node %d HighTotal:    %8lu kB\n"
                        "Node %d HighFree:     %8lu kB\n"
                        "Node %d LowTotal:     %8lu kB\n"
-                       "Node %d LowFree:      %8lu kB\n",
+                       "Node %d LowFree:      %8lu kB\n"
+                       "Node %d Dirty:        %8lu kB\n"
+                       "Node %d Writeback:    %8lu kB\n"
+                       "Node %d Mapped:       %8lu kB\n"
+                       "Node %d Slab:         %8lu kB\n",
                        nid, K(i.totalram),
                        nid, K(i.freeram),
                        nid, K(i.totalram - i.freeram),
@@ -64,7 +80,11 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                        nid, K(i.totalhigh),
                        nid, K(i.freehigh),
                        nid, K(i.totalram - i.totalhigh),
-                       nid, K(i.freeram - i.freehigh));
+                       nid, K(i.freeram - i.freehigh),
+                       nid, K(ps.nr_dirty),
+                       nid, K(ps.nr_writeback),
+                       nid, K(ps.nr_mapped),
+                       nid, K(ps.nr_slab));
         n += hugetlb_report_node_meminfo(nid, buf + n);
         return n;
 }