Re: [PATCH V4 4/6] memcg: add per cgroup writeback pages accounting
From: Michal Hocko <hidden>
Date: 2013-07-11 14:40:09
Also in:
linux-fsdevel, linux-mm
On Sat 06-07-13 01:32:57, Sha Zhengju wrote:
quoted hunk ↗ jump to hunk
From: Sha Zhengju <redacted> Similar to dirty page, we add per cgroup writeback pages accounting. The lock rule still is: mem_cgroup_begin_update_page_stat() modify page WRITEBACK stat mem_cgroup_update_page_stat() mem_cgroup_end_update_page_stat() There're two writeback interfaces to modify: test_{clear/set}_page_writeback(). Signed-off-by: Sha Zhengju <redacted> Acked-by: Michal Hocko <redacted> Acked-by: KAMEZAWA Hiroyuki <redacted> cc: Greg Thelen <redacted> cc: Andrew Morton <akpm@linux-foundation.org> cc: Fengguang Wu <redacted> cc: Mel Gorman <mgorman@suse.de> --- include/linux/memcontrol.h | 1 + mm/memcontrol.c | 5 +++++ mm/page-writeback.c | 15 +++++++++++++++ 3 files changed, 21 insertions(+)diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index f952be6..ccd35d8 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h@@ -43,6 +43,7 @@ enum mem_cgroup_stat_index { MEM_CGROUP_STAT_RSS_HUGE, /* # of pages charged as anon huge */ 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_WRITEBACK, /* # of pages under writeback */ MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */ MEM_CGROUP_STAT_NSTATS, };diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 1d31851..9126abc 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c@@ -92,6 +92,7 @@ static const char * const mem_cgroup_stat_names[] = { "mapped_file", "swap", "dirty", + "writeback",
Ordering issue again (see mem_cgroup_stat_index)
};
enum mem_cgroup_events_index {[...]
quoted hunk ↗ jump to hunk
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 3900e62..85de9a0 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c@@ -2008,11 +2008,17 @@ EXPORT_SYMBOL(account_page_dirtied); /* * Helper function for set_page_writeback family. + * + * The caller must hold mem_cgroup_begin/end_update_page_stat() lock + * while modifying struct page state and accounting writeback pages.
I guess "while calling this function" would be sufficient
+ * See test_set_page_writeback for example.
+ *
* NOTE: Unlike account_page_dirtied this does not rely on being atomic
* wrt interrupts.
*/
void account_page_writeback(struct page *page)
{
+ mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
inc_zone_page_state(page, NR_WRITEBACK);
}
EXPORT_SYMBOL(account_page_writeback);[...] -- Michal Hocko SUSE Labs