Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1321823

Re: [PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more precise

From Michal Hocko <mhocko@kernel.org>
Newsgroups linux.kernel
Subject Re: [PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more precise
Date 2016-01-29 16:20 +0100
Message-ID <qWj05-517-19@gated-at.bofh.it> (permalink)
References <qG2wi-7PJ-13@gated-at.bofh.it> <qW28W-R2-3@gated-at.bofh.it> <qWeD8-1qJ-29@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On Fri 29-01-16 19:35:18, Tetsuo Handa wrote:
> Michal Hocko wrote:
> > From: Michal Hocko <mhocko@suse.com>
> > 
> > zone_reclaimable_pages is used in should_reclaim_retry which uses it to
> > calculate the target for the watermark check. This means that precise
> > numbers are important for the correct decision. zone_reclaimable_pages
> > uses zone_page_state which can contain stale data with per-cpu diffs
> > not synced yet (the last vmstat_update might have run 1s in the past).
> > 
> > Use zone_page_state_snapshot in zone_reclaimable_pages instead. None
> > of the current callers is in a hot path where getting the precise value
> > (which involves per-cpu iteration) would cause an unreasonable overhead.
> > 
> > Suggested-by: David Rientjes <rientjes@google.com>
> > Signed-off-by: Michal Hocko <mhocko@suse.com>
> > ---
> >  mm/vmscan.c | 14 +++++++-------
> >  1 file changed, 7 insertions(+), 7 deletions(-)
> > 
> 
> I didn't know http://lkml.kernel.org/r/20151021130323.GC8805@dhcp22.suse.cz
> was forgotten. Anyway,

OK, that explains why this sounded so familiar. Sorry I comepletely
forgot about it.

> Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>

Can I change it to your Signed-off-by?

-- 
Michal Hocko
SUSE Labs

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more precise Michal Hocko <mhocko@kernel.org> - 2016-01-28 22:20 +0100
  Re: [PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more  precise David Rientjes <rientjes@google.com> - 2016-01-29 00:30 +0100
  Re: [PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more precise "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2016-01-29 04:50 +0100
  Re: [PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more precise Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2016-01-29 11:40 +0100
    Re: [PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more precise Michal Hocko <mhocko@kernel.org> - 2016-01-29 16:20 +0100
      Re: [PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more precise Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2016-01-29 22:40 +0100

csiph-web