From: trd@45mercystreet.com (Toby Douglass)
To: linux-arm-kernel@lists.infradead.org
Subject: CAS implementation may be broken
Date: Wed, 25 Nov 2009 01:34:21 +0100 [thread overview]
Message-ID: <4B0C7B8D.3010800@45mercystreet.com> (raw)
In-Reply-To: <20091124225605.GJ17481@n2100.arm.linux.org.uk>
Russell King - ARM Linux wrote:
> On Tue, Nov 24, 2009 at 11:34:56PM +0100, Toby Douglass wrote:
>> Additionally; the DMB afterwards seemed to have no value. You could
>> perform the STREX and then your thread could pause indefinitely and were
>> you in a situation where you store was not immediately visible or
>> correctly ordered to another thread, that thread would then read the old
>> value.
> The two DMBs are there to prevent other loads and stores on the _local_
> CPU being speculated inside the compare-and-swap operation, either by
> the compiler or the CPU.
Ahhh!
Forest, trees, etc...
next prev parent reply other threads:[~2009-11-25 0:34 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-04 18:09 GCC built-in atomic operations and memory barriers Toby Douglass
2009-11-04 19:05 ` Russell King - ARM Linux
2009-11-04 20:12 ` Toby Douglass
2009-11-04 21:03 ` Russell King - ARM Linux
2009-11-06 19:10 ` Toby Douglass
2009-11-04 22:09 ` Gilles Chanteperdrix
2009-11-06 19:17 ` Toby Douglass
2009-11-21 15:21 ` CAS implementation may be broken Toby Douglass
2009-11-23 15:08 ` Russell King - ARM Linux
2009-11-23 19:10 ` Toby Douglass
2009-11-23 20:06 ` Russell King - ARM Linux
2009-11-23 20:34 ` Toby Douglass
2009-11-23 15:13 ` Catalin Marinas
2009-11-24 15:15 ` Toby Douglass
2009-11-24 15:36 ` Russell King - ARM Linux
2009-11-24 16:20 ` Toby Douglass
2009-11-24 16:27 ` Catalin Marinas
2009-11-24 17:14 ` Toby Douglass
2009-11-25 1:24 ` Jamie Lokier
2009-11-26 16:14 ` Toby Douglass
2009-11-27 1:37 ` Jamie Lokier
2009-11-24 15:33 ` Toby Douglass
2009-11-23 15:34 ` Catalin Marinas
2009-11-23 16:40 ` Toby Douglass
2009-11-23 22:28 ` Jamie Lokier
2009-11-23 23:13 ` Russell King - ARM Linux
2009-11-24 1:32 ` Jamie Lokier
2009-11-24 11:19 ` Catalin Marinas
2009-11-24 22:24 ` Toby Douglass
2009-11-25 11:11 ` Catalin Marinas
2009-11-25 18:57 ` Toby Douglass
2009-11-24 22:34 ` Toby Douglass
2009-11-24 22:56 ` Russell King - ARM Linux
2009-11-25 0:34 ` Toby Douglass [this message]
2009-11-24 9:38 ` Toby Douglass
2009-11-24 15:59 ` Catalin Marinas
2009-11-24 16:34 ` Toby Douglass
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=4B0C7B8D.3010800@45mercystreet.com \
--to=trd@45mercystreet.com \
--cc=linux-arm-kernel@lists.infradead.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).