From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: "Michael S. Zick" <lkml@morethan.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org
Subject: Re: [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic
Date: Fri, 22 May 2009 11:59:55 -0700 [thread overview]
Message-ID: <4A16F62B.40207@zytor.com> (raw)
In-Reply-To: <20090522183622.GA8385@elte.hu>
Ingo Molnar wrote:
> * Michael S. Zick <lkml@morethan.org> wrote:
>
>> Found in the bit-rot for 32-bit, x86, Uni-processor builds:
>>
>> diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
>> index f6aa18e..3c790ef 100644
>> --- a/arch/x86/include/asm/alternative.h
>> +++ b/arch/x86/include/asm/alternative.h
>> @@ -35,7 +35,7 @@
>> "661:\n\tlock; "
>>
>> #else /* ! CONFIG_SMP */
>> -#define LOCK_PREFIX ""
>> +#define LOCK_PREFIX "\n\tlock; "
>> #endif
>
> What is your motivation for this change? At first sight this makes
> the UP kernel a bit larger and a bit smaller. Are you fixing some
> real regression/bug here?
>
That looks very odd indeed. The whole point of the LOCK_PREFIX macro is
to squelch it on UP (locks that should not be squelched on UP should not
be annotated LOCK_PREFIX.)
-hpa
next prev parent reply other threads:[~2009-05-22 19:00 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-22 16:39 [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic Michael S. Zick
2009-05-22 18:23 ` Andi Kleen
2009-05-22 18:36 ` Ingo Molnar
2009-05-22 18:59 ` H. Peter Anvin [this message]
2009-05-22 19:20 ` Michael S. Zick
2009-05-22 22:21 ` Michael S. Zick
2009-05-22 23:30 ` H. Peter Anvin
2009-05-23 0:45 ` Michael S. Zick
2009-05-23 0:51 ` H. Peter Anvin
2009-05-23 10:44 ` Michael S. Zick
2009-05-23 11:18 ` Michael S. Zick
2009-05-24 7:04 ` Harald Welte
2009-05-24 12:48 ` Michael S. Zick
2009-05-24 15:43 ` Michael S. Zick
2009-05-27 22:13 ` Roland Dreier
2009-05-27 22:33 ` Michael S. Zick
2009-05-23 15:52 ` Michael S. Zick
2009-05-23 18:04 ` Michael S. Zick
2009-05-23 23:44 ` H. Peter Anvin
2009-05-24 6:49 ` Harald Welte
2009-05-24 12:38 ` Michael S. Zick
2009-05-24 17:31 ` Harald Welte
2009-05-27 12:18 ` Re:[VIA Support] was: " Michael S. Zick
2009-05-27 12:22 ` [VIA " Michael S. Zick
2009-05-27 12:47 ` Harald Welte
2009-05-27 13:00 ` Michael S. Zick
2009-05-29 12:06 ` Michael S. Zick
2009-05-30 15:48 ` Michael S. Zick
2009-05-24 12:27 ` Michael S. Zick
2009-05-24 17:22 ` Harald Welte
2009-05-24 18:00 ` H. Peter Anvin
2009-05-24 18:32 ` Michael S. Zick
2009-05-24 18:46 ` H. Peter Anvin
2009-05-24 19:09 ` Michael S. Zick
2009-05-25 19:03 ` Michael S. Zick
2009-05-25 19:18 ` Michael S. Zick
2009-05-25 19:46 ` Michael S. Zick
2009-05-25 21:10 ` Michael S. Zick
2009-05-25 21:17 ` H. Peter Anvin
2009-05-25 23:03 ` Michael S. Zick
2009-05-25 23:35 ` Michael S. Zick
2009-05-26 0:05 ` H. Peter Anvin
2009-05-26 12:37 ` Michael S. Zick
2009-05-26 17:13 ` H. Peter Anvin
2009-05-25 1:31 ` i2c-viapro / via-fb drivers on VIA CX700 Harald Welte
2009-05-25 12:54 ` Michael S. Zick
2009-05-27 13:36 ` Michael S. Zick
2009-05-25 16:05 ` [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic Michael S. Zick
2009-05-28 20:30 ` Pavel Machek
2009-05-28 20:54 ` Michael S. Zick
2009-05-28 23:15 ` [Futex RFC] was " Michael S. Zick
2009-05-29 2:00 ` Michael S. Zick
2009-05-27 17:01 ` LOCK prefix on uni processor has its use (was Re: [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic) Harald Welte
2009-05-27 17:10 ` Michael S. Zick
2009-05-27 17:19 ` Thomas Gleixner
2009-05-27 17:25 ` Michael S. Zick
2009-05-27 18:08 ` LOCK prefix on uni processor has its use Andi Kleen
2009-05-27 18:22 ` Michael S. Zick
2009-05-27 18:33 ` Michael S. Zick
2009-05-27 18:55 ` Michael S. Zick
2009-05-27 18:38 ` Andi Kleen
2009-06-02 12:48 ` Harald Welte
2009-06-02 13:03 ` Andi Kleen
2009-06-02 13:26 ` Michael S. Zick
2009-06-02 13:42 ` Andi Kleen
2009-06-03 11:46 ` Michael S. Zick
2009-05-28 2:56 ` LOCK prefix on uni processor has its use (was Re: [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic) H. Peter Anvin
2009-05-23 20:51 ` [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic Michael S. Zick
2009-05-28 12:48 ` Pavel Machek
2009-05-28 13:29 ` Michael S. Zick
2009-05-28 20:50 ` Pavel Machek
2009-05-28 20:58 ` Michael S. Zick
2009-05-28 21:16 ` Pavel Machek
2009-05-28 21:21 ` Michael S. Zick
2009-05-22 19:17 ` Michael S. Zick
[not found] ` <200905221343.30638.lkml@morethan.org>
[not found] ` <20090522192329.GF846@one.firstfloor.org>
2009-05-22 19:53 ` Michael S. Zick
2009-05-22 20:05 ` Samuel Thibault
2009-05-22 20:32 ` Michael S. Zick
2009-05-22 20:42 ` Andi Kleen
2009-05-22 20:57 ` Michael S. Zick
2009-05-22 20:43 ` Samuel Thibault
2009-05-22 21:59 ` Andi Kleen
2009-05-22 22:00 ` Samuel Thibault
2009-05-22 22:14 ` Andi Kleen
2009-05-22 22:14 ` Samuel Thibault
2009-05-22 20:45 ` Roland Dreier
2009-05-24 18:59 ` Robert Hancock
-- strict thread matches above, loose matches on Subject: below --
2009-05-22 18:50 Michael S. Zick
2009-05-22 19:24 ` Roland Dreier
2009-05-22 20:03 ` Michael S. Zick
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