mm, vmscan: add active list aging tracepoint
Our reclaim process has several tracepoints to tell us more about how
things are progressing. We are, however, missing a tracepoint to track
active list aging. Introduce mm_vmscan_lru_shrink_active which reports
the number of
- nr_taken is number of isolated pages from the active list
- nr_referenced pages which tells us that we are hitting referenced
pages which are deactivated. If this is a large part of the
reported nr_deactivated pages then we might be hitting into
the active list too early because they might be still part of
the working set. This might help to debug performance issues.
- nr_active pages which tells us how many pages are kept on the
active list - mostly exec file backed pages. A high number can
indicate that we might be trashing on executables.
[mhocko@suse.com: update]
Link: http://lkml.kernel.org/r/20170104135244.GJ25453@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170104101942.4860-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 files changed