From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757846AbZDTWlo (ORCPT ); Mon, 20 Apr 2009 18:41:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756837AbZDTWlf (ORCPT ); Mon, 20 Apr 2009 18:41:35 -0400 Received: from mail-ew0-f176.google.com ([209.85.219.176]:52429 "EHLO mail-ew0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756354AbZDTWle (ORCPT ); Mon, 20 Apr 2009 18:41:34 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=ZEKQREc/v8Zs9v7FzJQ6lCy6prF12zS6gsC5GrtXx0ZiNdB16jTMg99EKXueZ4Z5MT WYqA8KrutU5/OKxqfcw/gRMah1gWtl03zsv4le9nvWDFKbivekbWXnTrMoWpRU7kdH0R ZK5yr0fTk4snWdPyn4dnEybeeHtXpQG/h7IBU= Date: Tue, 21 Apr 2009 00:41:30 +0200 From: Frederic Weisbecker To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton Subject: Re: [PATCH 2/2] tracing: use nowakeup version of commit for function event trace tests Message-ID: <20090420224129.GB5997@nowhere> References: <20090420222257.267399830@goodmis.org> <20090420222325.267573793@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090420222325.267573793@goodmis.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 20, 2009 at 06:22:59PM -0400, Steven Rostedt wrote: > From: Steven Rostedt > > The startup tests for the event tracer also runs with the function > tracer enabled. The "wakeup" version of the trace commit was used > which can grab spinlocks. If a task was preempted by an NMI > that called a function being traced, it could deadlock due to the > function tracer trying to grab the same lock. > > Thanks to Frederic Weisbecker for pointing out where the bug was. > > Reported-by: Ingo Molnar > Reported-by: Frederic Weisbecker > Signed-off-by: Steven Rostedt > --- Aah, I was about to push my version, which was the same but with a more weird changelog :-) Frederic. > kernel/trace/trace_events.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c > index 98daf5d..672b195 100644 > --- a/kernel/trace/trace_events.c > +++ b/kernel/trace/trace_events.c > @@ -1164,7 +1164,7 @@ function_test_events_call(unsigned long ip, unsigned long parent_ip) > entry->ip = ip; > entry->parent_ip = parent_ip; > > - trace_current_buffer_unlock_commit(event, flags, pc); > + trace_nowake_buffer_unlock_commit(event, flags, pc); > > out: > atomic_dec(&per_cpu(test_event_disable, cpu)); > -- > 1.6.2.1 > > -- > -- > 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/