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From: Chris Murphy <lists@colorremedies.com>
To: unlisted-recipients:; (no To-header on input)
Cc: Christian Rohmann <crohmann@netcologne.de>,
	"Austin S. Hemmelgarn" <ahferroin7@gmail.com>,
	linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: btrfs-progs 4.4 re-balance of RAID6 is very slow / limited to one cpu core?
Date: Tue, 9 Feb 2016 19:23:10 -0700	[thread overview]
Message-ID: <CAJCQCtSTNr7YGz+ASRBBOgtZEbPiBN-k8yWtUnUM-p4UXrsaFA@mail.gmail.com> (raw)
In-Reply-To: <CAJCQCtTPQE+hBzaktURR1v3GtObSjH=UV806qU-RmFVomwK3GA@mail.gmail.com>

# perf stat -e 'btrfs:*' -a sleep 10


## This is single device HDD, balance of a root fs was started before
these 10 seconds of sampling. There are some differences in the
statistics depending on whether there are predominately reads or
writes for the balance, so clearly balance does predominately reads,
then predominately writes. Unsurprising but the three tries I did were
largely in agreement (orders of magnitude wise).
http://fpaste.org/320551/06921614/


# perf record -e block:block_rq_issue -ag
^C   ## after ~30 seconds
# perf report

## Single device HDD, balance of root fs start before perf record.
There's a lot of data, collapsed by default. I expanded a few items at
random just as an example. I suspect the write of the perf.data file
is a non-factor because it was just under 2MiB.
http://fpaste.org/320555/14550698/raw/


# perf top

## Single device HDD, balance of root fs start before issuing this
command, and let it run for about 20 seconds. This is actually not as
interesting as I thought it might be, but I don't really know what I'm
looking for. I'd need something else to compare it to.
http://fpaste.org/320559/55070873/


Anyway, all of these are single device, so it's not apples/apples
comparison, but it is a working (full speed for the block device)
balance.


Chris Murphy

  reply	other threads:[~2016-02-10  2:23 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-22 13:38 btrfs-progs 4.4 re-balance of RAID6 is very slow / limited to one cpu core? Christian Rohmann
2016-01-22 14:51 ` Duncan
2016-01-24  2:30 ` Henk Slager
2016-01-25 11:34   ` Christian Rohmann
2016-01-25 22:13     ` Chris Murphy
     [not found]       ` <CAKZK7uxdX9UBPOKButtPjqBOdVUfHdRTimP+W34fkz1h9P+wHg@mail.gmail.com>
2016-01-26  0:44         ` Fwd: " Justin Brown
2016-01-26  5:17           ` Chris Murphy
2016-01-26  6:14             ` Chris Murphy
2016-01-26  8:54               ` Christian Rohmann
2016-01-26 19:26                 ` Chris Murphy
2016-01-26 19:27                   ` Chris Murphy
2016-01-26 19:57                   ` Austin S. Hemmelgarn
2016-01-26 20:20                     ` Chris Murphy
2016-01-27  8:48                       ` Christian Rohmann
2016-01-27 16:34                         ` Austin S. Hemmelgarn
2016-01-27 20:58                           ` bbrendon
2016-01-27 21:53                           ` Chris Murphy
2016-01-28 12:27                             ` Austin S. Hemmelgarn
2016-02-01 14:10                             ` Christian Rohmann
2016-02-01 20:52                               ` Chris Murphy
2016-02-09 13:48                                 ` Christian Rohmann
2016-02-09 16:46                                   ` Marc MERLIN
2016-02-09 21:46                                   ` Chris Murphy
2016-02-10  2:23                                     ` Chris Murphy [this message]
2016-02-10  2:36                                       ` Chris Murphy
2016-02-10 13:19                                     ` Christian Rohmann
2016-02-10 19:16                                       ` Chris Murphy
2016-02-10 19:38                                         ` Chris Murphy

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