From: Pavel Machek <pavel@ucw.cz>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: valdis.kletnieks@vt.edu,
kernel list <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@osdl.org>,
vbabka@suse.cz, aarcange@redhat.com, rientjes@google.com,
mhocko@kernel.org, zi.yan@cs.rutgers.edu, hannes@cmpxchg.org,
jack@suse.cz
Subject: Re: [regression -next0117] What is kcompactd and why is he eating 100% of my cpu?
Date: Sun, 27 Jan 2019 17:00:27 +0100 [thread overview]
Message-ID: <20190127160027.GA9340@amd> (raw)
In-Reply-To: <20190127141556.GB9565@techsingularity.net>
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Hi!
> > > top - 13:38:51 up 1:42, 16 users, load average: 1.41, 1.93, 1.62
> > > Tasks: 182 total, 3 running, 138 sleeping, 0 stopped, 0 zombie
> > > %Cpu(s): 2.3 us, 57.8 sy, 0.0 ni, 39.9 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
> > > KiB Mem: 3020044 total, 2429420 used, 590624 free, 27468 buffers
> > > KiB Swap: 2097148 total, 0 used, 2097148 free. 1924268 cached Mem
> > >
> > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
> > > 608 root 20 0 0 0 0 R 99.6 0.0 11:34.38 kcompactd0
> > > 9782 root 20 0 0 0 0 I 7.9 0.0 0:59.02 kworker/0:
> > > 2971 root 20 0 46624 23076 13576 S 4.3 0.8 2:50.22 Xorg
> >
> > I've noticed this as well on earlier kernels (next-20181224 to 20190115)
> >
> > Some more info:
> >
> > 1) echo 3 > /proc/sys/vm/drop_caches unwedges kcompactd in 1-3 seconds.
> >
>
> This aspect is curious as it indicates that kcompactd could potentially
> be infinite looping but it's not something I've experienced myself. By
> any chance is there a preditable reproduction case for this?
I seen it exactly once, so not sure how reproducible this is. x86-32
machine, running chromium browser, so yes, there was some swapping
involved.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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next prev parent reply other threads:[~2019-01-27 16:00 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-26 20:00 [regression -next0117] What is kcompactd and why is he eating 100% of my cpu? Pavel Machek
2019-01-27 2:56 ` valdis.kletnieks
2019-01-27 14:09 ` Mel Gorman
2019-01-27 14:15 ` Mel Gorman
2019-01-27 16:00 ` Pavel Machek [this message]
2019-01-27 21:36 ` valdis.kletnieks
2019-01-28 9:16 ` Jan Kara
2019-01-28 10:57 ` Sergey Senozhatsky
2019-01-28 11:03 ` Mel Gorman
2019-01-30 1:06 ` valdis.kletnieks
2019-01-30 4:29 ` valdis.kletnieks
2019-01-30 10:40 ` Mel Gorman
2021-01-25 18:54 ` Tibor Bana
2021-01-26 8:52 ` Valdis Klētnieks
2021-01-26 9:17 ` Mel Gorman
2021-01-27 19:29 ` Tibor Bana
2021-02-16 12:36 ` Jason A. Donenfeld
2021-02-16 22:33 ` Valdis Klētnieks
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