From: Joonsoo Kim <js1304@gmail.com>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux Memory Management List <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Michal Hocko <mhocko@kernel.org>, Hugh Dickins <hughd@google.com>,
Minchan Kim <minchan@kernel.org>,
Vlastimil Babka <vbabka@suse.cz>,
Mel Gorman <mgorman@techsingularity.net>,
kernel-team@lge.com, Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [PATCH v2 1/9] mm/vmscan: make active/inactive ratio as 1:1 for anon lru
Date: Fri, 13 Mar 2020 14:48:46 +0900 [thread overview]
Message-ID: <CAAmzW4PW8Z7r7PoFUsAqSY9JpGB4iqxKodO5aath+2QrMSUeJg@mail.gmail.com> (raw)
In-Reply-To: <20200312144749.GG29835@cmpxchg.org>
2020년 3월 12일 (목) 오후 11:47, Johannes Weiner <hannes@cmpxchg.org>님이 작성:
>
> On Thu, Feb 20, 2020 at 02:11:45PM +0900, js1304@gmail.com wrote:
> > From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> >
> > Current implementation of LRU management for anonymous page has some
> > problems. Most important one is that it doesn't protect the workingset,
> > that is, pages on the active LRU list. Although, this problem will be
> > fixed in the following patchset, the preparation is required and
> > this patch does it.
> >
> > What following patchset does is to restore workingset protection. In this
> > case, newly created or swap-in pages are started their lifetime on the
> > inactive list. If inactive list is too small, there is not enough chance
> > to be referenced and the page cannot become the workingset.
> >
> > In order to provide enough chance to the newly anonymous pages, this patch
> > makes active/inactive LRU ratio as 1:1.
>
> Patch 8/9 is a revert of this patch. I assume you did this for the
> series to be bisectable and partially revertable, but I'm not sure
> keeping only the first and second patch would be safe: they reduce
> workingset protection quite dramatically on their own (on a 10G system
> from 90% of RAM to 50% e.g.) and likely cause regressions.
>
> So while patch 2 is probably a lot better with patch 1 than without,
Yes, it is what I intended.
> it seems a bit unnecessary since we cannot keep patch 2 on its own. We
> need the rest of the series to make these changes.
Yes, you're right.
> On the other hand, the patch is small and obviously correct. So no
> strong feelings either way.
Okay. I will keep the patches since I think that these patches will
help someone who want to understand the LRU management.
> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
>
> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Thanks!
next prev parent reply other threads:[~2020-03-13 5:48 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-20 5:11 [PATCH v2 0/9] workingset protection/detection on the anonymous LRU list js1304
2020-02-20 5:11 ` [PATCH v2 1/9] mm/vmscan: make active/inactive ratio as 1:1 for anon lru js1304
2020-03-12 14:47 ` Johannes Weiner
2020-03-13 5:48 ` Joonsoo Kim [this message]
2020-03-13 5:48 ` Joonsoo Kim
2020-02-20 5:11 ` [PATCH v2 2/9] mm/vmscan: protect the workingset on anonymous LRU js1304
2020-03-12 15:14 ` Johannes Weiner
2020-03-13 7:40 ` Joonsoo Kim
2020-03-13 7:40 ` Joonsoo Kim
2020-03-13 19:55 ` Johannes Weiner
2020-03-16 7:05 ` Joonsoo Kim
2020-03-16 7:05 ` Joonsoo Kim
2020-03-16 16:12 ` Johannes Weiner
2020-03-17 4:52 ` Joonsoo Kim
2020-03-17 4:52 ` Joonsoo Kim
2020-02-20 5:11 ` [PATCH v2 3/9] mm/workingset: extend the workingset detection for anon LRU js1304
2020-02-20 5:11 ` [PATCH v2 4/9] mm/swapcache: support to handle the value in swapcache js1304
2020-02-20 5:11 ` [PATCH v2 5/9] mm/workingset: use the node counter if memcg is the root memcg js1304
2020-02-20 5:11 ` [PATCH v2 6/9] mm/workingset: handle the page without memcg js1304
2020-02-20 5:11 ` [PATCH v2 7/9] mm/swap: implement workingset detection for anonymous LRU js1304
2020-02-20 5:11 ` [PATCH v2 8/9] mm/vmscan: restore active/inactive ratio " js1304
2020-02-20 5:11 ` [PATCH v2 9/9] mm/swap: count a new anonymous page as a reclaim_state's rotate js1304
2020-02-27 3:39 ` [PATCH v2 0/9] workingset protection/detection on the anonymous LRU list Andrew Morton
2020-02-27 7:48 ` Joonsoo Kim
2020-03-01 4:40 ` Andrew Morton
2020-02-27 13:48 ` Johannes Weiner
2020-02-27 23:36 ` Andrew Morton
2020-03-02 23:31 ` Joonsoo Kim
2020-03-02 23:31 ` Joonsoo Kim
2020-03-11 7:27 ` Joonsoo Kim
2020-03-11 7:27 ` Joonsoo Kim
2020-02-28 3:23 ` Aaron Lu
2020-02-28 4:03 ` Joonsoo Kim
2020-02-28 5:57 ` Aaron Lu
2020-02-28 6:52 ` Joonsoo Kim
2020-02-28 9:17 ` Aaron Lu
2020-02-28 9:56 ` Joonsoo Kim
2020-02-28 10:21 ` Aaron Lu
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