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 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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome