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From: Johannes Weiner <hannes@cmpxchg.org>
To: js1304@gmail.com
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-mm@kvack.org, 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: Thu, 12 Mar 2020 10:47:49 -0400	[thread overview]
Message-ID: <20200312144749.GG29835@cmpxchg.org> (raw)
In-Reply-To: <1582175513-22601-2-git-send-email-iamjoonsoo.kim@lge.com>

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,
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.

On the other hand, the patch is small and obviously correct. So no
strong feelings either way.

> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>


  reply	other threads:[~2020-03-12 14:47 UTC|newest]

Thread overview: 32+ 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 [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 19:55       ` Johannes Weiner
2020-03-16  7:05         ` Joonsoo Kim
2020-03-16 16:12           ` Johannes Weiner
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
2020-03-11  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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