Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754519Ab3HJSXM (ORCPT ); Sat, 10 Aug 2013 14:23:12 -0400 Received: from mail.skyhub.de ([78.46.96.112]:42122 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753745Ab3HJSXL (ORCPT ); Sat, 10 Aug 2013 14:23:11 -0400 Date: Sat, 10 Aug 2013 20:23:09 +0200 From: Borislav Petkov To: Linus Torvalds Cc: Andi Kleen , Linux Kernel Mailing List , the arch/x86 maintainers , Ingo Molnar , Andi Kleen Subject: Re: [PATCH 10/13] x86: Move cond resched for copy_{from,to}_user into low level code 64bit Message-ID: <20130810182309.GA5714@pd.tnic> References: <1376089460-5459-1-git-send-email-andi@firstfloor.org> <1376089460-5459-11-git-send-email-andi@firstfloor.org> <20130810161031.GK19750@two.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1221 Lines: 28 On Sat, Aug 10, 2013 at 09:27:33AM -0700, Linus Torvalds wrote: > Now, the *debug* logic is entirely different, of course. Maybe the > problem is that we have mixed up the two so badly, and we have > "might_sleep()" that implies more of a debug issue than a preemption > issue, and then people add those because they want the debug coverage > (and then you *absolutely* want it even for a single-byte user > mode access). And then because the concept is tied together with > preemption, we end up doing preemption even for that single-byte > access despite the fact that it makes no sense what-so-ever. Sounds like the debug aspect and the preemption point addition need to be sorf-of split into two different functions/macros and each used separately. Something like keep the current might_sleep and have debug_sleep or similar which does only __might_sleep without the resched... -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is 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/