From: Johannes Weiner <hannes@cmpxchg.org>
To: sarah <sarah@thesharps.us>
Cc: Mel Gorman <mgorman@suse.de>,
linux-mm@kvack.org, intel-gfx@lists.freedesktop.org
Subject: Re: Kswapd 100% CPU since 3.8 on Sandybridge
Date: Sun, 26 Oct 2014 14:20:43 -0400 [thread overview]
Message-ID: <20141026182043.GA28435@phnom.home.cmpxchg.org> (raw)
In-Reply-To: <20141026160057.GA5234@puck>
Hi Sarah,
On Sun, Oct 26, 2014 at 09:05:34AM -0700, sarah wrote:
> One hypothesis I had was the system was hanging because kswapd was hammering on
> the disk, and it was really low on disk space (< 1 GB). But I've moved about 20
> GB of roadtrip photos to my USB 3.0 drive, and I can still replicate the slow
> system behavior. I was also poking around /etc/fstab, and I realized that I had
> actually disabled my swap partition around the 3.12 kernel time frame to see if
> that helped the issue. That lead me to wonder why kswapd was running at all?
Kswapd isn't just there to swap, it reclaims pages in the background
when memory is filling up in order to keep allocation latencies low.
That includes trimming the page cache, shrinking slabs, even writing
back dirty pages. So "kswapd" is a bit of a misnomer, and it's
expected to run even when you don't have any swap space configured.
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prev parent reply other threads:[~2014-10-26 18:20 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CABe+QzA=0YVpQ8rN+3X-cbH6JP1nWTvp2spb93P9PqJhmjBROA@mail.gmail.com>
[not found] ` <CABe+QzA-E40bFFXYJBc663Kx0KrE3xy2uZq5xOH2XL6mFPA6+w@mail.gmail.com>
2014-10-04 17:05 ` Sarah A Sharp
2014-10-06 7:25 ` Daniel Vetter
2014-10-06 9:37 ` Mel Gorman
2014-10-06 13:32 ` Daniel Vetter
2014-10-26 16:05 ` sarah
2014-10-26 18:20 ` Johannes Weiner [this message]
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