Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758128Ab0BRMch (ORCPT ); Thu, 18 Feb 2010 07:32:37 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:44482 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754651Ab0BRMcf (ORCPT ); Thu, 18 Feb 2010 07:32:35 -0500 Subject: Re: [PATCH 09/10] x86-32: use SSE for atomic64_read/set if available From: Peter Zijlstra To: Luca Barbieri Cc: mingo@elte.hu, hpa@zytor.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org In-Reply-To: References: <1266406962-17463-1-git-send-email-luca@luca-barbieri.com> <1266406962-17463-10-git-send-email-luca@luca-barbieri.com> <1266488742.26719.119.camel@laptop> <1266490846.26719.206.camel@laptop> Content-Type: text/plain; charset="UTF-8" Date: Thu, 18 Feb 2010 13:32:26 +0100 Message-ID: <1266496346.26719.464.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 800 Lines: 18 On Thu, 2010-02-18 at 13:29 +0100, Luca Barbieri wrote: > >> If we use the stack instead of per-CPU variables, all IRQs and NMIs > >> preserve CR0 and the SSE registers, so this would be safe, right? > > > > You'd have to take special care to deal with nested IRQs I think. > > Could you elaborate on that? > Which issue could there be with nested IRQs? Depends on where on the stack you're going to save things, I through you'd take space in the thread_info struct, but I guess if you're simply going to push the reg onto the stack it should be fine. -- 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/