From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753698Ab0G0XSm (ORCPT ); Tue, 27 Jul 2010 19:18:42 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:42902 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751310Ab0G0XSi (ORCPT ); Tue, 27 Jul 2010 19:18:38 -0400 Date: Tue, 27 Jul 2010 16:18:19 -0700 From: Andrew Morton To: monstr@monstr.eu Cc: rostedt@goodmis.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@elte.hu, linux-arch@vger.kernel.org Subject: Re: [PATCH] asm-generic: Use raw_local_irq_save/restore instead local_irq_save/restore Message-Id: <20100727161819.cf6feab1.akpm@linux-foundation.org> In-Reply-To: <4C4D4C2E.8010103@monstr.eu> References: <1274863724-14906-1-git-send-email-monstr@monstr.eu> <1274863724-14906-2-git-send-email-monstr@monstr.eu> <1274884963.22648.245.camel@gandalf.stny.rr.com> <20100526100805.171b3c48.akpm@linux-foundation.org> <4C4D4C2E.8010103@monstr.eu> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.9; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 26 Jul 2010 10:49:50 +0200 Michal Simek wrote: > start/stop_critical_timing function for preemptirqsoff, preemptoff > and irqsoff tracers contains atomic_inc and atomic_dec operations. > > Atomic operations used local_irq_save/restore macros to ensure > atomic access but they are traced by the same function which is causing > recursion problem. > > The reason is when these tracers are turn ON then local_irq_save/restore > macros are changed in include/linux/irqflags.h to call trace_hardirqs_on/off > which call start/stop_critical_timing. > > Microblaze was affected because use generic atomic implementation. Seems that this will also affect blackfin, mn10300 and score. I guess they aren't supporting tracing yet? > Signed-off-by: Michal Simek > Acked-by: Steven Rostedt > Signed-off-by: Andrew Morton hm, I wonder how my signoff got there. Doesn't matter.