From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Jens Axboe <axboe@suse.de>
Cc: Neil Brown <neilb@cse.unsw.edu.au>,
Christoph Hellwig <hch@lst.de>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: bug in md write barrier support?
Date: Wed, 08 Sep 2004 23:21:39 +0100 [thread overview]
Message-ID: <1094682098.12280.19.camel@localhost.localdomain> (raw)
In-Reply-To: <20040908154608.GN2258@suse.de>
On Mer, 2004-09-08 at 16:46, Jens Axboe wrote:
> That's a worry if it really does that - does it, or are you just
> speculating about possible problems?
I2O defines cache flush very losely. It flushes the cache and returns
when the cache has been flushed. From playing with the controllers I
have it seems some at least merge further queued writes into the output
stream. Thus if I issue
write 1, 2, 3, 4 , 40, 41, flush cache, write 5, 6, 100
it'll write 1,2,3,4,5,6, 40, 41, report flush cache complete.
Obviously I can implement full barrier semantics in the driver if need
be but that would cost performance hence the question.
next prev parent reply other threads:[~2004-09-08 23:27 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-03 17:24 bug in md write barrier support? Christoph Hellwig
2004-09-04 0:56 ` Neil Brown
2004-09-04 8:21 ` Jens Axboe
2004-09-06 1:36 ` Neil Brown
2004-09-08 9:23 ` Jens Axboe
2004-09-08 13:35 ` Alan Cox
2004-09-08 15:46 ` Jens Axboe
2004-09-08 22:21 ` Alan Cox [this message]
2004-09-09 8:06 ` Jens Axboe
2004-09-09 8:22 ` Arjan van de Ven
2004-09-09 8:29 ` Jens Axboe
2004-09-09 12:51 ` Alan Cox
2004-09-09 14:34 ` Jens Axboe
2004-09-12 17:13 ` Rogier Wolff
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1094682098.12280.19.camel@localhost.localdomain \
--to=alan@lxorguk.ukuu.org.uk \
--cc=axboe@suse.de \
--cc=hch@lst.de \
--cc=linux-kernel@vger.kernel.org \
--cc=neilb@cse.unsw.edu.au \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.