From: "H. Peter Anvin" <hpa@zytor.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Luca Barbieri <luca@luca-barbieri.com>,
mingo@elte.hu, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 08/10] x86-32: support atomic64_t on 386/486 UP/SMP
Date: Thu, 18 Feb 2010 07:20:38 -0800 [thread overview]
Message-ID: <4B7D5AC6.9070103@zytor.com> (raw)
In-Reply-To: <1266488746.26719.120.camel@laptop>
On 02/18/2010 02:25 AM, Peter Zijlstra wrote:
> On Wed, 2010-02-17 at 12:42 +0100, Luca Barbieri wrote:
>> This patch makes atomic64 use either the generic implementation or
>> the rewritten cmpxchg8b one just introduced by inserting a "call" to
>> either, using the alternatives system to dynamically switch the calls.
>>
>> This allows to use atomic64_t on 386/486 which lack cmpxchg8b
>
> IIRC we dropped <i586 SMP support, and since we don't have a PMU on
> those chips atomic64_t doesn't need to be NMI safe, so a simple
> UP-IRQ-disable implementation should suffice.
... which is what we have now, with the cmpxchg8b alternates emulation.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2010-02-18 15:24 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-17 11:42 [PATCH 0/10] x86-32: improve atomic64_t functions Luca Barbieri
2010-02-17 11:42 ` [PATCH 01/10] x86: add support for multiple choice alternatives Luca Barbieri
2010-02-17 12:47 ` Avi Kivity
2010-02-18 19:46 ` H. Peter Anvin
2010-02-17 11:42 ` [PATCH 02/10] x86: add support for relative CALL and JMP in alternatives Luca Barbieri
2010-02-18 19:40 ` H. Peter Anvin
2010-02-18 23:38 ` Luca Barbieri
2010-02-18 23:54 ` H. Peter Anvin
2010-02-19 14:27 ` Masami Hiramatsu
2010-02-17 11:42 ` [PATCH 03/10] x86: add support for lock prefix " Luca Barbieri
2010-02-17 11:42 ` [PATCH 04/10] x86-32: allow UP/SMP lock replacement in cmpxchg64 Luca Barbieri
2010-02-17 11:42 ` [PATCH 05/10] lib: add self-test for atomic64_t Luca Barbieri
2010-02-17 11:42 ` [PATCH 06/10] x86-32: rewrite 32-bit atomic64 functions in assembly Luca Barbieri
2010-02-17 11:42 ` [PATCH 07/10] lib: move generic atomic64 to atomic64-impl.h Luca Barbieri
2010-02-17 11:42 ` [PATCH 08/10] x86-32: support atomic64_t on 386/486 UP/SMP Luca Barbieri
2010-02-18 10:25 ` Peter Zijlstra
2010-02-18 10:58 ` Luca Barbieri
2010-02-18 15:20 ` H. Peter Anvin [this message]
2010-02-17 11:42 ` [PATCH 09/10] x86-32: use SSE for atomic64_read/set if available Luca Barbieri
2010-02-17 22:39 ` H. Peter Anvin
2010-02-18 0:41 ` Luca Barbieri
2010-02-18 0:47 ` H. Peter Anvin
2010-02-18 9:56 ` Avi Kivity
2010-02-18 10:07 ` Luca Barbieri
2010-02-18 8:23 ` Andi Kleen
2010-02-18 9:53 ` Luca Barbieri
2010-02-18 9:56 ` Luca Barbieri
2010-02-18 10:11 ` Andi Kleen
2010-02-18 10:27 ` Luca Barbieri
2010-02-18 15:24 ` H. Peter Anvin
2010-02-18 18:14 ` Luca Barbieri
2010-02-18 18:28 ` H. Peter Anvin
2010-02-18 18:42 ` Luca Barbieri
2010-02-18 19:07 ` H. Peter Anvin
2010-02-18 20:26 ` Andi Kleen
2010-02-18 16:52 ` H. Peter Anvin
2010-02-18 18:49 ` Luca Barbieri
2010-02-18 19:06 ` H. Peter Anvin
2010-02-18 19:43 ` Luca Barbieri
2010-02-18 19:45 ` Yuhong Bao
2010-02-18 10:24 ` Peter Zijlstra
2010-02-18 10:25 ` Peter Zijlstra
2010-02-18 10:50 ` Luca Barbieri
2010-02-18 11:00 ` Peter Zijlstra
2010-02-18 12:29 ` Luca Barbieri
2010-02-18 12:32 ` Peter Zijlstra
2010-02-18 13:45 ` Luca Barbieri
2010-02-17 11:42 ` [PATCH 10/10] x86-32: panic on !CX8 && XMM Luca Barbieri
2010-02-17 22:38 ` H. Peter Anvin
2010-02-17 23:00 ` Yuhong Bao
2010-02-17 23:41 ` H. Peter Anvin
2010-02-18 1:13 ` Yuhong Bao
2010-02-25 20:24 ` Yuhong Bao
2010-02-18 0:46 ` Luca Barbieri
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