Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755207Ab0BRStp (ORCPT ); Thu, 18 Feb 2010 13:49:45 -0500 Received: from mail-fx0-f220.google.com ([209.85.220.220]:47647 "EHLO mail-fx0-f220.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753761Ab0BRStn convert rfc822-to-8bit (ORCPT ); Thu, 18 Feb 2010 13:49:43 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=k6yl4if4LgM79j57VgHYFkqpLzLqGcXBK3cgL+d/1pOTxgkURDqDOexgwi3FK0J8mY 67OTPUdBLO5PpFo3o5X4v+s/GrNFQD0eflvadz7Ye/OLUsDrc617THJfSk6D096D7eWC Hz2j9rkpgMD9fxZTa5akvU9FwLTf7RpGqgQMA= MIME-Version: 1.0 In-Reply-To: <4B7D7060.1080908@zytor.com> References: <1266406962-17463-1-git-send-email-luca@luca-barbieri.com> <1266406962-17463-10-git-send-email-luca@luca-barbieri.com> <87eikj54wp.fsf@basil.nowhere.org> <20100218101156.GE5964@basil.fritz.box> <4B7D7060.1080908@zytor.com> Date: Thu, 18 Feb 2010 19:49:41 +0100 X-Google-Sender-Auth: 78c06ef8b95e4c6e Message-ID: Subject: Re: [PATCH 09/10] x86-32: use SSE for atomic64_read/set if available From: Luca Barbieri To: "H. Peter Anvin" Cc: Andi Kleen , mingo@elte.hu, a.p.zijlstra@chello.nl, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 843 Lines: 17 > 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/