On Mon, 28 Feb 2011 01:47:30 +0900
Minchan Kim [off-list ref] wrote:

On Fri, Feb 25, 2011 at 01:35:56PM -0800, Greg Thelen wrote:

quoted

Add memcg routines to track dirty, writeback, and unstable_NFS pages.
These routines are not yet used by the kernel to count such pages.
A later change adds kernel calls to these new routines.

Signed-off-by: Greg Thelen <redacted>
Signed-off-by: Andrea Righi <redacted>
Acked-by: KAMEZAWA Hiroyuki <redacted>
Acked-by: Daisuke Nishimura <redacted>
---
Changelog since v1:
- Renamed "nfs"/"total_nfs" to "nfs_unstable"/"total_nfs_unstable" in per cgroup
  memory.stat to match /proc/meminfo.
- Rename (for clarity):
  - mem_cgroup_write_page_stat_item -> mem_cgroup_page_stat_item
  - mem_cgroup_read_page_stat_item -> mem_cgroup_nr_pages_item
- Remove redundant comments.
- Made mem_cgroup_move_account_page_stat() inline.

 include/linux/memcontrol.h |    5 ++-
 mm/memcontrol.c            |   87 ++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 83 insertions(+), 9 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 3da48ae..e1f70a9 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h

@@ -25,9 +25,12 @@ struct page_cgroup;
 struct page;
 struct mm_struct;
 
-/* Stats that can be updated by kernel. */
+/* mem_cgroup page counts accessed by kernel. */

I confused by 'kernel', 'access'?
So, What's the page counts accessed by user?
I don't like such words.

Please, clarify the comment.
'Stats of page that can be tracking by memcg' or whatever.

Ah, yes. that's better.

quoted

 enum mem_cgroup_page_stat_item {
 	MEMCG_NR_FILE_MAPPED, /* # of pages charged as file rss */
+	MEMCG_NR_FILE_DIRTY, /* # of dirty pages in page cache */
+	MEMCG_NR_FILE_WRITEBACK, /* # of pages under writeback */
+	MEMCG_NR_FILE_UNSTABLE_NFS, /* # of NFS unstable pages */
 };
 
 extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1c2704a..38f786b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c

@@ -92,8 +92,11 @@ enum mem_cgroup_stat_index {
 	 */
 	MEM_CGROUP_STAT_CACHE, 	   /* # of pages charged as cache */
 	MEM_CGROUP_STAT_RSS,	   /* # of pages charged as anon rss */
-	MEM_CGROUP_STAT_FILE_MAPPED,  /* # of pages charged as file rss */
 	MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
+	MEM_CGROUP_STAT_FILE_MAPPED,  /* # of pages charged as file rss */
+	MEM_CGROUP_STAT_FILE_DIRTY,	/* # of dirty pages in page cache */
+	MEM_CGROUP_STAT_FILE_WRITEBACK,		/* # of pages under writeback */
+	MEM_CGROUP_STAT_FILE_UNSTABLE_NFS,	/* # of NFS unstable pages */
 	MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */
 	MEM_CGROUP_ON_MOVE,	/* someone is moving account between groups */
 	MEM_CGROUP_STAT_NSTATS,

@@ -1622,6 +1625,44 @@ void mem_cgroup_update_page_stat(struct page *page,
 			ClearPageCgroupFileMapped(pc);
 		idx = MEM_CGROUP_STAT_FILE_MAPPED;
 		break;
+
+	case MEMCG_NR_FILE_DIRTY:
+		/* Use Test{Set,Clear} to only un/charge the memcg once. */
+		if (val > 0) {
+			if (TestSetPageCgroupFileDirty(pc))
+				val = 0;
+		} else {
+			if (!TestClearPageCgroupFileDirty(pc))
+				val = 0;
+		}
+		idx = MEM_CGROUP_STAT_FILE_DIRTY;
+		break;
+
+	case MEMCG_NR_FILE_WRITEBACK:
+		/*
+		 * This counter is adjusted while holding the mapping's
+		 * tree_lock.  Therefore there is no race between settings and
+		 * clearing of this flag.
+		 */
+		if (val > 0)
+			SetPageCgroupFileWriteback(pc);
+		else
+			ClearPageCgroupFileWriteback(pc);
+		idx = MEM_CGROUP_STAT_FILE_WRITEBACK;
+		break;
+
+	case MEMCG_NR_FILE_UNSTABLE_NFS:
+		/* Use Test{Set,Clear} to only un/charge the memcg once. */
+		if (val > 0) {
+			if (TestSetPageCgroupFileUnstableNFS(pc))
+				val = 0;
+		} else {
+			if (!TestClearPageCgroupFileUnstableNFS(pc))
+				val = 0;
+		}
+		idx = MEM_CGROUP_STAT_FILE_UNSTABLE_NFS;
+		break;

This part can be simplified by some macro work.
But it's another issue.

Agreed, doing in another patch is better.

Thanks,
-Kame

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>