From: Fengguang Wu <fengguang.wu@intel.com>
To: Chris Mason <chris.mason@oracle.com>
Cc: Jan Kara <jack@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
Jeff Moyer <jmoyer@redhat.com>, Jens Axboe <axboe@kernel.dk>,
linux-fsdevel@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>,
Dave Chinner <david@fromorbit.com>,
Christoph Hellwig <hch@infradead.org>,
Shaohua Li <shli@fusionio.com>
Subject: Re: [PATCH] btrfs: lower metadata writeback threshold on low dirty threshold
Date: Thu, 3 May 2012 22:08:27 +0800 [thread overview]
Message-ID: <20120503140827.GA24981@localhost> (raw)
In-Reply-To: <20120503034311.GA14081@localhost>
On Thu, May 03, 2012 at 11:43:11AM +0800, Fengguang Wu wrote:
> This helps write performance when setting the dirty threshold to tiny numbers.
>
> 3.4.0-rc2 3.4.0-rc2-btrfs4+
> ------------ ------------------------
> 96.92 -0.4% 96.54 bay/thresh=1000M/btrfs-100dd-1-3.4.0-rc2
> 98.47 +0.0% 98.50 bay/thresh=1000M/btrfs-10dd-1-3.4.0-rc2
> 99.38 -0.3% 99.06 bay/thresh=1000M/btrfs-1dd-1-3.4.0-rc2
> 98.04 -0.0% 98.02 bay/thresh=100M/btrfs-100dd-1-3.4.0-rc2
> 98.68 +0.3% 98.98 bay/thresh=100M/btrfs-10dd-1-3.4.0-rc2
> 99.34 -0.0% 99.31 bay/thresh=100M/btrfs-1dd-1-3.4.0-rc2
> ==> 88.98 +9.6% 97.53 bay/thresh=10M/btrfs-10dd-1-3.4.0-rc2
> ==> 86.99 +13.1% 98.39 bay/thresh=10M/btrfs-1dd-1-3.4.0-rc2
> ==> 2.75 +2442.4% 69.88 bay/thresh=1M/btrfs-10dd-1-3.4.0-rc2
> ==> 3.31 +2634.1% 90.54 bay/thresh=1M/btrfs-1dd-1-3.4.0-rc2
Well, further tests show that it behaves very unstable:
3.4.0-rc2-btrfs4+ 3.4.0-rc2-btrfs5+
------------------------ ------------------------
69.88 +16.4% 81.31 bay/thresh=1M/btrfs-10dd-1-3.4.0-rc2-btrfs4+
71.09 +1.4% 72.05 bay/thresh=1M/btrfs-10dd-2-3.4.0-rc2-btrfs4+
72.60 -1.7% 71.38 bay/thresh=1M/btrfs-10dd-3-3.4.0-rc2-btrfs4+
90.54 -0.9% 89.74 bay/thresh=1M/btrfs-1dd-1-3.4.0-rc2-btrfs4+
89.17 -90.2% ==> 8.71 bay/thresh=1M/btrfs-1dd-2-3.4.0-rc2-btrfs4+
==> 14.96 +495.3% 89.06 bay/thresh=1M/btrfs-1dd-3-3.4.0-rc2-btrfs4+
408.23 +1.0% 412.26 TOTAL write_bw
Where the -btrfs5 kernel has one more patch to remove the write plug.
Thanks,
Fengguang
next prev parent reply other threads:[~2012-05-03 14:08 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-08 1:06 [RESEND][PATCH v2] block: remove plugging at buffered write time Wu Fengguang
2012-04-09 14:34 ` Jeff Moyer
2012-04-11 23:13 ` Andrew Morton
2012-04-12 1:32 ` Fengguang Wu
2012-04-12 2:20 ` Fengguang Wu
2012-04-12 14:26 ` Jan Kara
2012-04-13 1:40 ` Fengguang Wu
2012-05-03 3:43 ` [PATCH] btrfs: lower metadata writeback threshold on low dirty threshold Fengguang Wu
2012-05-03 3:53 ` [PATCH] writeback: initialize global_dirty_limit Fengguang Wu
2012-05-03 9:25 ` [PATCH] btrfs: lower metadata writeback threshold on low dirty threshold Jan Kara
2012-05-03 10:02 ` Fengguang Wu
2012-05-03 12:31 ` Chris Mason
2012-05-03 13:30 ` Josef Bacik
2012-05-03 14:08 ` Fengguang Wu [this message]
2012-05-06 6:01 ` [RESEND][PATCH v2] block: remove plugging at buffered write time Fengguang Wu
2012-05-06 9:58 ` Fengguang Wu
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