From: Sultan Alsawaf <sultan@kerneltoast.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: Stop kswapd early when nothing's waiting for it to free pages
Date: Wed, 19 Feb 2020 14:45:03 -0800 [thread overview]
Message-ID: <20200219224503.GB5190@sultan-book.localdomain> (raw)
In-Reply-To: <20200219112653.116de9db314dade1f6086696@linux-foundation.org>
On Wed, Feb 19, 2020 at 11:26:53AM -0800, Andrew Morton wrote:
> On Wed, 19 Feb 2020 10:25:22 -0800 Sultan Alsawaf <sultan@kerneltoast.com> wrote:
>
> > Keeping kswapd running when all the failed allocations that invoked it
> > are satisfied incurs a high overhead due to unnecessary page eviction
> > and writeback, as well as spurious VM pressure events to various
> > registered shrinkers. When kswapd doesn't need to work to make an
> > allocation succeed anymore, stop it prematurely to save resources.
>
> Seems sensible.
>
> Please fully describe the userspace-visible runtime effects of this
> change?
>
FWIW, it looks like the refcount API doesn't allow refcounts to be zero, so I'd
have to update this patch to use just plain atomic_t instead. But since there
doesn't seem to be much interest in this, I'll only send an updated patch if
it's desired.
Sultan
next prev parent reply other threads:[~2020-02-19 22:45 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-19 18:25 Sultan Alsawaf
2020-02-19 19:13 ` Dave Hansen
2020-02-19 19:40 ` Sultan Alsawaf
2020-02-19 20:05 ` Michal Hocko
2020-02-19 20:42 ` Sultan Alsawaf
2020-02-19 21:45 ` Mel Gorman
2020-02-19 22:42 ` Sultan Alsawaf
2020-02-20 10:19 ` Mel Gorman
2020-02-21 4:22 ` Sultan Alsawaf
2020-02-21 8:07 ` Michal Hocko
[not found] ` <20200221210824.GA3605@sultan-book.localdomain>
2020-02-21 21:24 ` Dave Hansen
2020-02-25 9:09 ` Michal Hocko
2020-02-25 17:12 ` Sultan Alsawaf
2020-02-26 9:05 ` Michal Hocko
2020-02-25 22:30 ` Shakeel Butt
2020-02-26 9:08 ` Michal Hocko
2020-02-26 17:00 ` Shakeel Butt
2020-02-26 17:41 ` Michal Hocko
2020-02-26 10:51 ` Hillf Danton
2020-02-26 17:04 ` Shakeel Butt
2020-02-27 1:48 ` Hillf Danton
2020-02-21 18:04 ` Shakeel Butt
2020-02-21 20:06 ` Sultan Alsawaf
2020-02-20 8:29 ` Michal Hocko
2020-02-19 19:26 ` Andrew Morton
2020-02-19 22:45 ` Sultan Alsawaf [this message]
2020-02-19 19:35 ` Michal Hocko
2020-02-21 4:30 ` [PATCH v2] " Sultan Alsawaf
2020-02-21 18:22 ` Ira Weiny
2020-02-21 20:00 ` Sultan Alsawaf
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