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From: Luca Barbieri <luca@luca-barbieri.com>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>,
	mingo@elte.hu, a.p.zijlstra@chello.nl, akpm@linux-foundation.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 09/10] x86-32: use SSE for atomic64_read/set if available
Date: Thu, 18 Feb 2010 19:49:41 +0100	[thread overview]
Message-ID: <ff13bc9a1002181049v2605b442y9f33008548b58d48@mail.gmail.com> (raw)
In-Reply-To: <4B7D7060.1080908@zytor.com>

> This really sounds like the wrong optimization.  These functions aren't
> exactly all that complex in assembly (which would also allow them to be
> simple cli/do stuff/sti), and instead relying on gcc features which may
> or may not be well supported on x86 is inviting breakage down the line.
>
> That is particularly damaging, since the remaining 486-class users tend
> to be deeply embedded and thus we only find problems later.

There is the downside of adding a whole 386/486-specific implementation.

It's not too hard though, and if we don't care about 486 SMP, it may
be a better option.

  reply	other threads:[~2010-02-18 18:49 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
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 [this message]
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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