From: "H. Peter Anvin" <hpa@zytor.com>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@elte.hu>,
Linus Torvalds <torvalds@linux-foundation.org>,
Joe Perches <joe@perches.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86_64 : support atomic ops with 64 bits integer values
Date: Sat, 16 Aug 2008 08:04:23 -0700 [thread overview]
Message-ID: <48A6EC77.8080904@zytor.com> (raw)
In-Reply-To: <20080816073926.GA19546@Krystal>
Mathieu Desnoyers wrote:
> x86_64 add/sub atomic ops does not seems to accept integer values bigger
> than 32 bits as immediates. Intel's add/sub documentation specifies they
> have to be passed as registers.
This is correct; this is in fact true for all instructions except "mov".
Whether it's sign- or zero-extending is sometimes subtle, but not in
these cases.
Do you happen to know if this is a manifest bug in the current kernel
(i.e. if there is anywhere we're using more than ±2 GB as a constant to
these functions?)
Either way, I'll queue this up to tip:x86/urgent if Ingo hasn't already
since this is a pure bug fix.
-hpa
next prev parent reply other threads:[~2008-08-16 15:08 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-16 7:39 [PATCH] x86_64 : support atomic ops with 64 bits integer values Mathieu Desnoyers
2008-08-16 15:04 ` H. Peter Anvin [this message]
2008-08-16 15:43 ` Mathieu Desnoyers
2008-08-16 17:30 ` Linus Torvalds
2008-08-16 21:19 ` [RFC PATCH] Fair rwlock Mathieu Desnoyers
2008-08-16 21:33 ` Linus Torvalds
2008-08-17 7:53 ` [RFC PATCH] Fair low-latency rwlock v3 Mathieu Desnoyers
2008-08-17 16:17 ` Linus Torvalds
2008-08-17 19:10 ` [RFC PATCH] Fair low-latency rwlock v5 Mathieu Desnoyers
2008-08-17 21:30 ` [RFC PATCH] Fair low-latency rwlock v5 (updated benchmarks) Mathieu Desnoyers
2008-08-18 18:59 ` [RFC PATCH] Fair low-latency rwlock v5 Linus Torvalds
2008-08-18 23:25 ` Paul E. McKenney
2008-08-19 6:04 ` Mathieu Desnoyers
2008-08-19 7:33 ` Mathieu Desnoyers
2008-08-19 9:06 ` Mathieu Desnoyers
2008-08-19 16:48 ` Linus Torvalds
2008-08-21 20:50 ` [RFC PATCH] Writer-biased low-latency rwlock v8 Mathieu Desnoyers
2008-08-21 21:00 ` Linus Torvalds
2008-08-21 21:15 ` Linus Torvalds
2008-08-21 22:22 ` Linus Torvalds
2008-08-23 5:09 ` Mathieu Desnoyers
2008-08-23 18:02 ` Linus Torvalds
2008-08-23 20:30 ` Mathieu Desnoyers
2008-08-23 21:40 ` Linus Torvalds
2008-08-21 21:26 ` H. Peter Anvin
2008-08-21 21:41 ` Linus Torvalds
2008-08-25 19:20 ` [RFC PATCH] Fair low-latency rwlock v5 Peter Zijlstra
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