From: Neil Brown <neilb@suse.de>
To: Stefan Bader <Stefan.Bader@de.ibm.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
dm-devel@redhat.com, linux-raid@vger.kernel.org,
Jens Axboe <jens.axboe@oracle.com>, David Chinner <dgc@sgi.com>
Subject: Re: [RFD] BIO_RW_BARRIER - what it means for devices, filesystems, and dm/md.
Date: Mon, 28 May 2007 11:37:20 +1000 [thread overview]
Message-ID: <18010.12880.258773.95448@notabene.brown> (raw)
In-Reply-To: message from Stefan Bader on Friday May 25
On Friday May 25, Stefan.Bader@de.ibm.com wrote:
> 2007/5/25, Neil Brown <neilb@suse.de>:
> > - Are there other bit that we could handle better?
> > BIO_RW_FAILFAST? BIO_RW_SYNC? What exactly do they mean?
> >
> BIO_RW_FAILFAST: means low-level driver shouldn't do much (or no)
> error recovery. Mainly used by mutlipath targets to avoid long SCSI
> recovery. This should just be propagated when passing requests on.
Is it "much" or "no"?
Would it be reasonable to use this for reads from a non-degraded
raid1? What about writes?
What I would really like is some clarification on what sort of errors
get retried, how often, and how much timeout there is..
And does the 'error' code returned in ->bi_end_io allow us to
differentiate media errors from other errors yet?
>
> BIO_RW_SYNC: means this is a bio of a synchronous request. I don't
> know whether there are more uses to it but this at least causes queues
> to be flushed immediately instead of waiting for more requests for a
> short time. Should also just be passed on. Otherwise performance gets
> poor since something above will rather wait for the current
> request/bio to complete instead of sending more.
Yes, this one is pretty straight forward.. I mentioned it more as a
reminder to my self that I really should support it in raid5 :-(
NeilBrown
next prev parent reply other threads:[~2007-05-28 1:37 UTC|newest]
Thread overview: 134+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-25 7:58 [RFD] BIO_RW_BARRIER - what it means for devices, filesystems, and dm/md Neil Brown
2007-05-25 7:58 ` Neil Brown
2007-05-25 11:15 ` David Chinner
2007-05-25 11:49 ` Jens Axboe
2007-05-25 14:49 ` Phillip Susi
2007-05-25 14:49 ` [dm-devel] " Phillip Susi
2007-05-28 18:32 ` Jens Axboe
2007-05-25 13:52 ` Stefan Bader
2007-05-28 1:37 ` Neil Brown [this message]
2007-05-29 9:12 ` Stefan Bader
2007-05-25 15:11 ` Phillip Susi
2007-05-25 15:11 ` [dm-devel] " Phillip Susi
2007-05-26 1:03 ` Andreas Dilger
2007-05-26 10:27 ` Tejun Heo
2007-05-28 1:30 ` Neil Brown
2007-05-28 2:45 ` David Chinner
2007-05-28 2:57 ` Neil Brown
2007-05-28 4:29 ` David Chinner
2007-05-28 4:29 ` David Chinner
2007-05-31 0:46 ` Neil Brown
2007-05-31 0:57 ` Alasdair G Kergon
2007-05-31 0:57 ` [dm-devel] " Alasdair G Kergon
2007-05-31 1:07 ` Alasdair G Kergon
2007-05-31 1:07 ` [dm-devel] " Alasdair G Kergon
2007-05-31 1:11 ` David Chinner
2007-05-31 1:11 ` [dm-devel] " David Chinner
2007-05-28 4:48 ` Timothy Shimmin
2007-05-29 6:45 ` Jeremy Higdon
2007-05-29 20:03 ` Phillip Susi
2007-05-29 23:48 ` David Chinner
2007-05-30 0:01 ` david
2007-05-30 6:17 ` David Chinner
2007-05-30 8:55 ` Stefan Bader
2007-05-30 8:55 ` Stefan Bader
2007-05-30 16:52 ` david
2007-05-30 16:52 ` david
2007-05-31 0:20 ` David Chinner
2007-05-31 6:26 ` Jens Axboe
2007-05-31 7:03 ` David Chinner
2007-05-31 7:06 ` Jens Axboe
2007-05-31 13:30 ` Bill Davidsen
2007-05-31 13:36 ` Jens Axboe
2007-06-01 16:04 ` Bill Davidsen
2007-06-02 14:51 ` Jens Axboe
2007-06-02 19:55 ` Bill Davidsen
2007-06-01 3:16 ` Tejun Heo
2007-06-01 3:16 ` Tejun Heo
2007-06-01 8:21 ` Jens Axboe
2007-06-01 8:21 ` Jens Axboe
2007-06-02 9:20 ` Tejun Heo
2007-06-02 14:34 ` Jens Axboe
2007-06-02 14:34 ` Jens Axboe
2007-06-02 22:57 ` Guy Watkins
2007-06-02 22:57 ` Guy Watkins
2007-06-04 7:39 ` Tejun Heo
2007-05-31 18:31 ` Phillip Susi
2007-05-31 19:00 ` Jens Axboe
2007-05-31 19:21 ` david
2007-05-31 19:21 ` david
2007-05-31 19:40 ` Jens Axboe
2007-05-31 23:34 ` David Chinner
2007-06-01 5:59 ` Neil Brown
2007-06-01 6:11 ` Jens Axboe
2007-06-01 7:53 ` David Chinner
2007-06-01 23:56 ` Bill Davidsen
2007-05-31 18:24 ` Phillip Susi
2007-05-31 18:24 ` Phillip Susi
2007-05-30 16:45 ` Phillip Susi
2007-05-30 20:27 ` [dm-devel] " Phillip Susi
2007-05-31 6:24 ` Jens Axboe
2007-05-31 6:24 ` [dm-devel] " Jens Axboe
2007-05-31 18:37 ` Phillip Susi
2007-05-31 18:58 ` Jens Axboe
2007-06-02 0:04 ` Bill Davidsen
2007-05-28 9:29 ` Tejun Heo
2007-05-28 9:43 ` Alasdair G Kergon
2007-05-28 9:43 ` [dm-devel] " Alasdair G Kergon
2007-05-29 9:25 ` Stefan Bader
2007-05-29 22:05 ` Alasdair G Kergon
2007-05-29 22:05 ` [dm-devel] " Alasdair G Kergon
2007-05-30 9:12 ` Stefan Bader
2007-05-30 10:41 ` Alasdair G Kergon
2007-05-30 10:41 ` [dm-devel] " Alasdair G Kergon
2007-05-30 16:55 ` Phillip Susi
2007-05-30 16:55 ` [dm-devel] " Phillip Susi
2007-05-31 11:14 ` Stefan Bader
2007-06-01 3:25 ` Tejun Heo
2007-06-01 3:25 ` [dm-devel] " Tejun Heo
2007-06-01 5:55 ` david
2007-06-01 5:55 ` [dm-devel] " david
2007-06-01 7:16 ` Tejun Heo
2007-06-01 17:07 ` Valdis.Kletnieks
2007-06-01 18:09 ` Tejun Heo
2007-07-10 18:39 ` Ric Wheeler
2007-07-10 23:40 ` Valdis.Kletnieks
2007-07-11 2:49 ` Tejun Heo
2007-07-11 22:44 ` Ric Wheeler
2007-07-12 17:34 ` Valdis.Kletnieks
2007-07-12 19:43 ` Ric Wheeler
2007-07-12 23:10 ` Guy Watkins
2007-07-12 23:10 ` Guy Watkins
2007-07-13 11:30 ` Ric Wheeler
2007-07-11 2:51 ` Tejun Heo
2007-05-29 19:59 ` Phillip Susi
2007-05-31 0:22 ` Neil Brown
2007-05-30 9:35 ` Jens Axboe
2007-07-05 12:28 ` Tejun Heo
2007-07-09 12:27 ` Jens Axboe
2007-07-18 10:56 ` [PATCH] block: cosmetic changes Tejun Heo
2007-07-18 10:56 ` Tejun Heo
2007-07-18 10:59 ` [PATCH] block: factor out bio_check_eod() Tejun Heo
2007-07-18 10:59 ` Tejun Heo
2007-07-18 11:06 ` Jens Axboe
2007-07-18 11:18 ` Tejun Heo
2007-07-18 11:18 ` Tejun Heo
2007-07-18 11:31 ` Jens Axboe
2007-07-18 11:31 ` Jens Axboe
2007-07-18 11:33 ` Tejun Heo
2007-07-18 11:33 ` Tejun Heo
2007-07-18 11:34 ` Jens Axboe
2007-07-18 11:34 ` Jens Axboe
2007-07-18 11:41 ` Tejun Heo
2007-07-18 11:41 ` Tejun Heo
2007-07-18 11:45 ` Jens Axboe
2007-07-18 11:49 ` Jens Axboe
2007-07-18 12:34 ` Tejun Heo
2007-07-18 12:31 ` Jens Axboe
2007-05-28 11:17 ` [RFD] BIO_RW_BARRIER - what it means for devices, filesystems, and dm/md Nikita Danilov
2007-05-31 3:31 ` Neil Brown
2007-05-28 14:43 ` Bill Davidsen
2007-05-28 14:43 ` Bill Davidsen
2007-05-31 0:37 ` Neil Brown
2007-05-31 12:28 ` Bill Davidsen
2007-05-31 12:28 ` Bill Davidsen
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