From: Jeff Garzik <jgarzik@pobox.com>
To: Clem Taylor <clemtaylor@comcast.net>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Any news on a higher performance sata_sil SIL_QUIRK_MOD15WRITE workaround?
Date: Thu, 12 Aug 2004 02:43:23 -0400 [thread overview]
Message-ID: <411B118B.4040802@pobox.com> (raw)
In-Reply-To: <411AFD2C.5060701@comcast.net>
Clem Taylor wrote:
> I've been really disappointed by the performance of the Silicon Image
> 3114 on my new x86_box. I spent a bunch of time looking into the
> problem, thinking it was a software RAID5 or xfs issue causing 4K IOs.
> I don't know why I didn't notice the 'applying Seagate errata fix' in
> dmesg until after I did a bunch of performance testing and realized that
> it was a sata_sil issue.
>
> So, I was wondering what I can do about this problem? I am not currently
Get a different controller + disk combination.
> getting enough disk performance to justify the amount spent on the
> system or enough to satisfy the application I'm working on. Before I go
> out and purchase a 3ware controller and re-install the machine (ouch),
> is there any chance of a better work around in the near future? I'd be
> more than willing to test out a patch.
>
> Is the problem with really with nblocks % 15 == 1? Or is the problem
> with nblocks % 15 == 0? If it is the later and I'm using xfs with 4K
> blocks, couldn't I just turn off the workaround or will the RAID5 driver
> potentially break up larger requests?
The problem is that the Silicon Image controller sends unusual -- but
legal -- block sizes to the SATA device.
Older Seagates cannot cope with this unique, but spec-correct behavior.
This issue cannot even be worked around with "nblocks % 15 == 1", as was
previously thought. Using that formula just makes the problem harder to
reproduce.
Further, I don't have any plans to address the performance issue, since
the set of affected drives is finite.
> It would seem that the root of the problem is a Seagate issue. Does
> anyone know if Seagate fixed the problem with a firmware update?
You could find out for us, and let us know :)
Jeff
next prev parent reply other threads:[~2004-08-12 6:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-12 5:16 Any news on a higher performance sata_sil SIL_QUIRK_MOD15WRITE workaround? Clem Taylor
2004-08-12 6:43 ` Jeff Garzik [this message]
2004-08-12 12:00 ` Alan Cox
2004-08-12 15:16 ` Jeff Garzik
2004-08-12 19:59 ` Alan Cox
2004-08-12 21:03 ` Jeff Garzik
2004-08-12 20:37 ` Alan Cox
2004-08-13 4:18 ` Clem Taylor
2004-08-13 12:13 ` Alan Cox
2004-08-16 18:49 ` Eric Mudama
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