Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758648AbZA2Ufk (ORCPT ); Thu, 29 Jan 2009 15:35:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753372AbZA2Ufb (ORCPT ); Thu, 29 Jan 2009 15:35:31 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:52445 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753296AbZA2Ufa (ORCPT ); Thu, 29 Jan 2009 15:35:30 -0500 Date: Thu, 29 Jan 2009 21:35:17 +0100 From: Ingo Molnar To: Cliff Wickman , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, tj@kernel.org Subject: Re: [PATCH] x86: UV cleanup Message-ID: <20090129203517.GE12819@elte.hu> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1423 Lines: 44 * Cliff Wickman wrote: > From: Cliff Wickman > > This patch tweaks a couple things: > > - uv_flush_tlb_others() > the WARN_ON(!in_atomic()); fails if CONFIG_PREEMPT is not enabled > > The #ifdef may not be the right fix. The fix is probably in the > in_atomic macro, but I'm not sure what in_atomic() should return > if CONFIG_PREEMPT is turned off. I tested making it return 1 in that > case, but that yielded tons of warnings. > > The simpler fix for tlb_uv.c would be to just drop the WARN_ON. > > - uv_flush_send_and_wait() should return a pointer if the broadcast > remote tlb shootdown requests fail. That causes the conventional IPI > method of shootdown to be used. hm, this isnt a cleanup but a fix - i.e. needs to go into x86/urgent as a separate patch, right? and this: > @@ -316,7 +316,9 @@ const struct cpumask *uv_flush_tlb_other > int locals = 0; > struct bau_desc *bau_desc; > > +#ifdef CONFIG_PREEMPT > WARN_ON(!in_atomic()); > +#endif is indeed somewhat ugly - and we have no proper primitive to test for atomicity. (mainly because we dont know about atomicity on a non-preempt kernel) Ingo -- 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/