From: James Bottomley <James.Bottomley@SteelEye.com>
To: John David Anglin <dave@hiauly1.hia.nrc.ca>
Cc: parisc-linux@parisc-linux.org
Subject: Re: [parisc-linux] coherent ops and mb() revisited
Date: 05 Sep 2004 10:36:43 -0400 [thread overview]
Message-ID: <1094395005.1690.1.camel@mulgrave> (raw)
In-Reply-To: <200409050627.i856RWW3027615@hiauly1.hia.nrc.ca>
On Sun, 2004-09-05 at 02:27, John David Anglin wrote:
> > I think the best implementation is probably
> >
> > barrier();
> > a = __ldcw_align(x);
>
> I don't understand why you put the barrier before the __ldcw_align
> operation. The alignment operation is non-critical and could be done
> much earlier if that's desireable from a scheduling standpoint.
Actually, you're right. I think all we need is the mb() after the
spin_lock code and another mb before the spin_unlock code. How the
taking or releasing of the lock is optimised by gcc should be irrelevant
as long as it's locked when we cross the barrier.
James
_______________________________________________
parisc-linux mailing list
parisc-linux@lists.parisc-linux.org
http://lists.parisc-linux.org/mailman/listinfo/parisc-linux
next prev parent reply other threads:[~2004-09-05 14:36 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-05 1:38 [parisc-linux] coherent ops and mb() revisited Grant Grundler
2004-09-05 2:56 ` James Bottomley
2004-09-05 6:27 ` John David Anglin
2004-09-05 14:36 ` James Bottomley [this message]
2004-09-06 4:19 ` Grant Grundler
2004-09-06 9:24 ` John David Anglin
2004-09-06 14:15 ` James Bottomley
2004-09-07 15:17 ` Grant Grundler
2004-09-07 15:30 ` James Bottomley
2004-09-08 16:52 ` Grant Grundler
2004-09-08 17:11 ` James Bottomley
2004-09-10 16:11 ` Grant Grundler
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=1094395005.1690.1.camel@mulgrave \
--to=james.bottomley@steeleye.com \
--cc=dave@hiauly1.hia.nrc.ca \
--cc=parisc-linux@parisc-linux.org \
/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.