From: Dick Streefland <dick.streefland@altium.nl>
To: Erik Cumps <erik.cumps@esaturnus.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Unexpected slow block device write IO performance compared to uncached, unsynced direct IO using stock kernels
Date: Wed, 2 Sep 2015 16:12:23 +0200 [thread overview]
Message-ID: <20150902141223.GA31906@altium.nl> (raw)
In-Reply-To: <20150901091535.GA21329@altium.nl>
On Tuesday 2015-09-01 11:15, Dick Streefland wrote:
| I'm seeing this as well here on a number of new Dell Optiplex 7020
| machines and one older Optiplex 780, all with 8GB RAM and running
| Ubuntu 14.04 in 32-bit mode.
It turned out that the dirty thresholds in /proc/vmstat became zero:
nr_dirty_threshold 0
nr_dirty_background_threshold 0
A workaround is:
# sysctl vm.highmem_is_dirtyable=1
--
Dick
prev parent reply other threads:[~2015-09-02 14:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-16 13:56 Erik Cumps
2015-06-18 7:35 ` Erik Cumps
2015-09-01 9:15 ` Dick Streefland
2015-09-02 14:12 ` Dick Streefland [this message]
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