From: "Tony Battersby" <tonyb@cybernetics.com>
To: 'James Bottomley' <James.Bottomley@SteelEye.com>
Cc: 'Alan Cox' <alan@lxorguk.ukuu.org.uk>,
'SCSI Mailing List' <linux-scsi@vger.kernel.org>,
marcelo@conectiva.com.br, dougg@torque.net
Subject: RE: [PATCH] 2.4.21 fix race condition in sg.c
Date: Fri, 27 Jun 2003 10:57:01 -0400 [thread overview]
Message-ID: <002a01c33cbc$5e45d960$e0019d89@cybernetics.com> (raw)
In-Reply-To: <1056723054.1825.16.camel@mulgrave>
> I don't believe any of the above applies to the sg request
> pointer done flag.
I see a situation analogous to this:
CPU #0:
foo = result;
smp_wmb();
done = 1;
CPU #1:
if (done)
return foo;
Isn't smp_wmb() necessary to prevent the CPU from re-ordering the stores?
In the actual code, "foo" corresponds to fields like the SCSI return status,
sense data, and the data transfer residual.
Sorry if I am wrong about this. I couldn't find much documentation on the
proper use of barriers.
Anthony J. Battersby
Cybernetics
next prev parent reply other threads:[~2003-06-27 14:42 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-06-27 13:52 [PATCH] 2.4.21 fix race condition in sg.c Tony Battersby
2003-06-27 14:10 ` James Bottomley
2003-06-27 14:31 ` Alan Cox
2003-06-27 14:47 ` James Bottomley
2003-06-27 14:57 ` Tony Battersby [this message]
2003-06-27 15:00 ` Jeff Garzik
2003-06-27 15:11 ` James Bottomley
2003-06-27 15:38 ` Tony Battersby
-- strict thread matches above, loose matches on Subject: below --
2003-06-26 15:18 Tony Battersby
2003-06-26 22:15 ` Douglas Gilbert
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='002a01c33cbc$5e45d960$e0019d89@cybernetics.com' \
--to=tonyb@cybernetics.com \
--cc=James.Bottomley@SteelEye.com \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=dougg@torque.net \
--cc=linux-scsi@vger.kernel.org \
--cc=marcelo@conectiva.com.br \
/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