From: Matthew Wilcox <willy@infradead.org>
To: Wei Yang <richardw.yang@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>,
akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, shakeelb@google.com,
yang.shi@linux.alibaba.com
Subject: Re: [RFC Patch] mm/vmscan.c: not inherit classzone_idx from previous reclaim
Date: Thu, 13 Feb 2020 18:48:06 -0800 [thread overview]
Message-ID: <20200214024806.GU7778@bombadil.infradead.org> (raw)
In-Reply-To: <20200214020515.GC20833@richard>
On Fri, Feb 14, 2020 at 10:05:15AM +0800, Wei Yang wrote:
> On Wed, Feb 12, 2020 at 07:43:33AM +0000, Mel Gorman wrote:
> >Broadly speaking it was driven by cases whereby kswapd either a) fell
> >asleep prematurely and there were many stalls in direct reclaim before
> >kswapd recovered, b) stalls in direct reclaim immediately after kswapd went
> >to sleep or c) kswapd reclaimed for lower zones and went to sleep while
> >parallel tasks were direct reclaiming in higher zones or higher orders.
>
> Thanks for your explanation. I am trying to understand the connection between
> those cases and the behavior of kswapd.
>
> In summary, all three cases are related to direct reclaim, while happens in
> three different timing of kswapd:
Reclaim performed by kswapd is the opposite of direct reclaim. Direct
reclaim is reclaim initiated by a task which is trying to allocate memory.
If a task cannot perform direct reclaim itself, it may ask kswapd to
attempt to reclaim memory for it.
next prev parent reply other threads:[~2020-02-14 2:48 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-09 7:41 Wei Yang
2020-02-11 10:42 ` Mel Gorman
2020-02-12 2:25 ` Wei Yang
2020-02-12 7:43 ` Mel Gorman
2020-02-14 2:05 ` Wei Yang
2020-02-14 2:48 ` Matthew Wilcox [this message]
2020-02-14 7:35 ` Wei Yang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200214024806.GU7778@bombadil.infradead.org \
--to=willy@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=richardw.yang@linux.intel.com \
--cc=shakeelb@google.com \
--cc=yang.shi@linux.alibaba.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox