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From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Tibor Bana <bana.tibor@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>,
	valdis.kletnieks@vt.edu, Jan Kara <jack@suse.cz>,
	Pavel Machek <pavel@ucw.cz>,
	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
Subject: Re: [regression -next0117] What is kcompactd and why is he eating 100% of my cpu?
Date: Tue, 16 Feb 2021 13:36:22 +0100	[thread overview]
Message-ID: <YCu8RuhvU1Env7OF@zx2c4.com> (raw)
In-Reply-To: <20210125195438.c8d0e7980da0c2931d4f3056@gmail.com>

On Mon, Jan 25, 2021 at 07:54:38PM +0100, Tibor Bana wrote:
> Greetings!
> 
> I don't know if it still actual, but I am strugling with this problem right now and searching the internet for solutions.
> I read the thread and saw that you are strugling to reproduce the problem, and I can reproduce it almost every day.
> 
> - Install vmware player, and a linux guest. 
> - Configure the virtual machine to have a good amount of memory and cpu
> - run resource intensive tasks on the guest
> - when the host used up almost it's all memory and start to reuse caches kcompactd will kick in.
> 
> As I know the problem is related to transparent huge pages, but I tried to disable it. 
> Today I saw the problem again and kcompactd shown an interesting status in top. It hasn't used any memory, all zeroes but it used up one core completely. 
> 
> My machine is a core-i7 with 4 physical cores and hyper threading and 24GB Memory
> 5.9.11-arch2-1 #1 SMP PREEMPT Sat, 28 Nov 2020 02:07:22 +0000 x86_64 GNU/Linux

Another anecdote: 5.11.0, 64 gigs of ram. If I run QEMU/KVM for a VM
with 16 gigs at the same time as a VMware VM with 16 gigs of ram,
kcompact goes wild and both VMs get really slow. The key here is running
KVM at the same time as VMware.


  parent reply	other threads:[~2021-02-16 12:37 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
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 [this message]
2021-02-16 22:33                     ` Valdis Klētnieks

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