From: "Brian J. Watson" <Brian.J.Watson@compaq.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: marcelo@conectiva.com.br, linux-kernel@vger.kernel.org,
dhowells@redhat.com, hch@caldera.de
Subject: Re: [PATCH] 2.4.18-pre9, trylock for read/write semaphores
Date: Tue, 12 Feb 2002 17:47:11 -0800 [thread overview]
Message-ID: <3C69C59F.F86BF8F9@compaq.com> (raw)
In-Reply-To: <E16amMb-0003RQ-00@the-village.bc.nu>
Alan Cox wrote:
>
> > + new = old + RWSEM_ACTIVE_READ_BIAS;
> > + if (cmpxchg(&sem->count, old, new) == old)
> > + return 1;
>
> cmpxchg isnt present on i386
According to arch/i386/config.in, the generic spinlock version would be
used for vintage 386 chips. I think that's due to similar concerns about
the xadd instruction.
--
Brian Watson | "Now I don't know, but I been told it's
Linux Kernel Developer | hard to run with the weight of gold,
Open SSI Clustering Project | Other hand I heard it said, it's
Compaq Computer Corp | just as hard with the weight of lead."
Los Angeles, CA | -Robert Hunter, 1970
mailto:Brian.J.Watson@compaq.com
http://opensource.compaq.com/
next prev parent reply other threads:[~2002-02-13 2:07 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-02-12 22:45 [PATCH] 2.4.18-pre9, trylock for read/write semaphores bwatson
2002-02-12 23:29 ` Alan Cox
2002-02-13 1:47 ` Brian J. Watson [this message]
2002-02-13 7:47 ` David Howells
2002-02-13 8:19 ` David Howells
2002-02-14 0:13 ` Brian J. Watson
-- strict thread matches above, loose matches on Subject: below --
2002-02-21 18:04 Kendrick M. Smith
2002-02-21 21:54 ` Brian J. Watson
2002-02-21 23:02 ` Kendrick M. Smith
2002-02-21 23:26 ` Brian J. Watson
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=3C69C59F.F86BF8F9@compaq.com \
--to=brian.j.watson@compaq.com \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=dhowells@redhat.com \
--cc=hch@caldera.de \
--cc=linux-kernel@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 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.