Re: [PATCH] mm: fix up the vmscan stat in vmstat

[Johannes Weiner <hannes@cmpxchg.org>]

On Thu, Apr 12, 2012 at 12:24:49PM -0700, Ying Han wrote:
> On Thu, Apr 12, 2012 at 12:05 PM, Johannes Weiner <hannes@cmpxchg.org> wrote:
> > On Thu, Apr 12, 2012 at 11:03:02AM -0700, Ying Han wrote:
> >> It is always confusing on stat "pgsteal" where it counts both direct
> >> reclaim as well as background reclaim. However, we have "kswapd_steal"
> >> which also counts background reclaim value.
> >>
> >> This patch fixes it and also makes it match the existng "pgscan_" stats.
> >>
> >> Test:
> >> pgsteal_kswapd_dma32 447623
> >> pgsteal_kswapd_normal 42272677
> >> pgsteal_kswapd_movable 0
> >> pgsteal_direct_dma32 2801
> >> pgsteal_direct_normal 44353270
> >> pgsteal_direct_movable 0
> >>
> >> Signed-off-by: Ying Han <yinghan@google.com>
> >> ---
> >>  include/linux/vm_event_item.h |    5 +++--
> >>  mm/vmscan.c                   |   11 ++++++++---
> >>  mm/vmstat.c                   |    4 ++--
> >>  3 files changed, 13 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
> >> index 03b90cdc..06f8e38 100644
> >> --- a/include/linux/vm_event_item.h
> >> +++ b/include/linux/vm_event_item.h
> >> @@ -26,13 +26,14 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
> >>               PGFREE, PGACTIVATE, PGDEACTIVATE,
> >>               PGFAULT, PGMAJFAULT,
> >>               FOR_ALL_ZONES(PGREFILL),
> >> -             FOR_ALL_ZONES(PGSTEAL),
> >> +             FOR_ALL_ZONES(PGSTEAL_KSWAPD),
> >> +             FOR_ALL_ZONES(PGSTEAL_DIRECT),
> >>               FOR_ALL_ZONES(PGSCAN_KSWAPD),
> >>               FOR_ALL_ZONES(PGSCAN_DIRECT),
> >>  #ifdef CONFIG_NUMA
> >>               PGSCAN_ZONE_RECLAIM_FAILED,
> >>  #endif
> >> -             PGINODESTEAL, SLABS_SCANNED, KSWAPD_STEAL, KSWAPD_INODESTEAL,
> >> +             PGINODESTEAL, SLABS_SCANNED, KSWAPD_INODESTEAL,
> >>               KSWAPD_LOW_WMARK_HIT_QUICKLY, KSWAPD_HIGH_WMARK_HIT_QUICKLY,
> >>               KSWAPD_SKIP_CONGESTION_WAIT,
> >>               PAGEOUTRUN, ALLOCSTALL, PGROTATED,
> >> diff --git a/mm/vmscan.c b/mm/vmscan.c
> >> index 33c332b..078c9fd 100644
> >> --- a/mm/vmscan.c
> >> +++ b/mm/vmscan.c
> >> @@ -1568,9 +1568,14 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
> >>       reclaim_stat->recent_scanned[0] += nr_anon;
> >>       reclaim_stat->recent_scanned[1] += nr_file;
> >>
> >> -     if (current_is_kswapd())
> >> -             __count_vm_events(KSWAPD_STEAL, nr_reclaimed);
> >> -     __count_zone_vm_events(PGSTEAL, zone, nr_reclaimed);
> >> +     if (global_reclaim(sc)) {
> >> +             if (current_is_kswapd())
> >> +                     __count_zone_vm_events(PGSTEAL_KSWAPD, zone,
> >> +                                            nr_reclaimed);
> >> +             else
> >> +                     __count_zone_vm_events(PGSTEAL_DIRECT, zone,
> >> +                                            nr_reclaimed);
> >> +     }
> >
> > Hey, you changed more than the changelog said!  Why no longer count
> > memcg hard limit-triggered activity?
> 
> To make it consistent with "PGSCAN_*" stats, as in the commit log..
> Although i could be more specific. :(

My mistake then, I thought it was just in regard of naming and didn't
check how PGSCAN_* is accounted.

> I think it is good to keep those stats to be global reclaim, and memcg
> hardlimit-triggered should go to memory.vmscan_stat as you presented.

Ok.

--
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>