From: Roman Mamedov <rm@romanrm.net>
To: "Konstantin V. Gavrilenko" <k.gavrilenko@arhont.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: Btrfs + compression = slow performance and high cpu usage
Date: Fri, 28 Jul 2017 22:48:35 +0500 [thread overview]
Message-ID: <20170728224835.41c98aea@natsu> (raw)
In-Reply-To: <8446582.541.1501260065690.JavaMail.gkos@dynomob>
On Fri, 28 Jul 2017 17:40:50 +0100 (BST)
"Konstantin V. Gavrilenko" <k.gavrilenko@arhont.com> wrote:
> Hello list,
>
> I am stuck with a problem of btrfs slow performance when using compression.
>
> when the compress-force=lzo mount flag is enabled, the performance drops to 30-40 mb/s and one of the btrfs processes utilises 100% cpu time.
> mount options: btrfs relatime,discard,autodefrag,compress=lzo,compress-force,space_cache=v2,commit=10
It does not work like that, you need to set compress-force=lzo (and remove
compress=).
With your setup I believe you currently use compress-force[=zlib](default),
overriding compress=lzo, since it's later in the options order.
Secondly,
> autodefrag
This sure sounded like a good thing to enable? on paper? right?...
The moment you see anything remotely weird about btrfs, this is the first
thing you have to disable and retest without. Oh wait, the first would be
qgroups, this one is second.
Finally, what is the reasoning behind "commit=10", and did you check with the
default value of 30?
--
With respect,
Roman
next prev parent reply other threads:[~2017-07-28 17:48 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <33040946.535.1501254718807.JavaMail.gkos@dynomob>
2017-07-28 16:40 ` Btrfs + compression = slow performance and high cpu usage Konstantin V. Gavrilenko
2017-07-28 17:48 ` Roman Mamedov [this message]
2017-07-28 18:20 ` William Muriithi
2017-07-28 18:37 ` Hugo Mills
2017-07-28 18:08 ` Peter Grandi
2017-07-30 13:42 ` Konstantin V. Gavrilenko
2017-07-31 11:41 ` Peter Grandi
2017-07-31 12:33 ` Peter Grandi
2017-07-31 12:49 ` Peter Grandi
2017-08-01 9:58 ` Konstantin V. Gavrilenko
2017-08-01 10:53 ` Paul Jones
2017-08-01 13:14 ` Peter Grandi
2017-08-01 18:09 ` Konstantin V. Gavrilenko
2017-08-01 20:09 ` Peter Grandi
2017-08-01 23:54 ` Peter Grandi
2017-08-31 10:56 ` Konstantin V. Gavrilenko
2017-07-28 18:44 ` Peter Grandi
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