From: Phil Turmel <philip@turmel.org>
To: Robert Kierski <rkierski@cray.com>,
Dallas Clement <dallas.a.clement@gmail.com>
Cc: "linux-raid@vger.kernel.org" <linux-raid@vger.kernel.org>
Subject: Re: RAID 5,6 sequential writing seems slower in newer kernels
Date: Thu, 3 Dec 2015 09:37:52 -0500 [thread overview]
Message-ID: <566053C0.4060706@turmel.org> (raw)
In-Reply-To: <F7761B9B1D11B64BBB666019E9378117FDDF2F@CFWEX01.americas.cray.com>
On 12/03/2015 08:43 AM, Robert Kierski wrote:
> This is why I use Direct-IO to the bare metal block device instead of going through the FS. Rather than discussing the real problem, we're off in the weed talking about whether the tests should be using O_SYNC and whether there is a problem introduced in the latest version of the FS.
It's not off in the weeds for Dallas, the OP.
> FS's and cache are very good at hiding the problems of those things below them and prevent you from exercising the code you're interested in debugging.
Yep, you seem to have a real problem.
Phil
next prev parent reply other threads:[~2015-12-03 14:37 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-01 23:02 RAID 5,6 sequential writing seems slower in newer kernels Dallas Clement
2015-12-02 1:07 ` keld
2015-12-02 14:18 ` Robert Kierski
2015-12-02 14:45 ` Phil Turmel
2015-12-02 15:28 ` Robert Kierski
2015-12-02 15:37 ` Phil Turmel
2015-12-02 15:44 ` Robert Kierski
2015-12-02 15:51 ` Phil Turmel
2015-12-02 19:50 ` Dallas Clement
2015-12-03 0:12 ` Dallas Clement
2015-12-03 2:18 ` Phil Turmel
2015-12-03 2:24 ` Dallas Clement
2015-12-03 2:33 ` Dallas Clement
2015-12-03 2:38 ` Phil Turmel
2015-12-03 2:51 ` Dallas Clement
2015-12-03 4:30 ` Phil Turmel
2015-12-03 4:49 ` Dallas Clement
2015-12-03 13:43 ` Robert Kierski
2015-12-03 14:37 ` Phil Turmel [this message]
2015-12-03 2:34 ` Phil Turmel
2015-12-03 14:19 ` Robert Kierski
2015-12-03 14:39 ` Dallas Clement
2015-12-03 15:04 ` Phil Turmel
2015-12-03 22:21 ` Weedy
2015-12-04 13:40 ` Robert Kierski
2015-12-04 16:08 ` Dallas Clement
2015-12-07 14:29 ` Robert Kierski
2015-12-08 19:38 ` Dallas Clement
2015-12-08 21:24 ` Robert Kierski
2015-12-04 18:51 ` Shaohua Li
2015-12-05 1:38 ` Dallas Clement
2015-12-07 14:18 ` Robert Kierski
2015-12-02 15:37 ` Robert Kierski
2015-12-02 5:22 ` Roman Mamedov
2015-12-02 14:15 ` Robert Kierski
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