From: Marat Khalili <mkh@rqc.ru>
To: linux-btrfs@vger.kernel.org
Subject: Do different btrfs volumes compete for CPU?
Date: Fri, 31 Mar 2017 10:05:20 +0300 [thread overview]
Message-ID: <43a14754-1047-552e-78a9-6503dfc0d121@rqc.ru> (raw)
Approximately 16 hours ago I've run a script that deleted >~100
snapshots and started quota rescan on a large USB-connected btrfs volume
(5.4 of 22 TB occupied now). Quota rescan only completed just now, with
100% load from [btrfs-transacti] throughout this period, which is
probably ~ok depending on your view on things.
What worries me is innocent process using _another_, SATA-connected
btrfs volume that hung right after I started my script and took >30
minutes to be sigkilled. There's nothing interesting in the kernel log,
and attempts to attach strace to the process output nothing, but I of
course suspect that it freezed on disk operation.
I wonder:
1) Can there be a contention for CPU or some mutexes between kernel
btrfs threads belonging to different volumes?
2) If yes, can anything be done about it other than mounting volumes
from (different) VMs?
> $ uname -a; btrfs --version
> Linux host 4.4.0-66-generic #87-Ubuntu SMP Fri Mar 3 15:29:05 UTC 2017
> x86_64 x86_64 x86_64 GNU/Linux
> btrfs-progs v4.4
--
With Best Regards,
Marat Khalili
next reply other threads:[~2017-03-31 7:05 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-31 7:05 Marat Khalili [this message]
2017-03-31 11:49 ` Do different btrfs volumes compete for CPU? Duncan
2017-03-31 12:28 ` Marat Khalili
2017-04-01 2:04 ` Duncan
2017-04-01 10:17 ` Peter Grandi
2017-04-03 8:02 ` Marat Khalili
2017-04-04 17:36 ` Peter Grandi
2017-04-05 7:04 ` Marat Khalili
2017-04-07 0:17 ` Martin
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