Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751625Ab3IFMlI (ORCPT ); Fri, 6 Sep 2013 08:41:08 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:14281 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751328Ab3IFMlG (ORCPT ); Fri, 6 Sep 2013 08:41:06 -0400 X-Authority-Analysis: v=2.0 cv=ddwCLAre c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=Pg0uVeabA7wA:10 a=5SG0PmZfjMsA:10 a=kj9zAlcOel0A:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=RZDpadHLlpEA:10 a=3nbZYyFuAAAA:8 a=3dYWILzd2BM54esBrhkA:9 a=CjuIK1q_8ugA:10 a=EvKJbDF4Ut8A:10 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Date: Fri, 6 Sep 2013 08:41:04 -0400 From: Steven Rostedt To: Masami Hiramatsu Cc: Tom Zanussi , linux-kernel@vger.kernel.org, "Paul E. McKenney" Subject: Re: [PATCH v8 01/10] tracing: Add support for SOFT_DISABLE to syscall events Message-ID: <20130906084104.2c1e8774@gandalf.local.home> In-Reply-To: <5229C8F7.7060000@hitachi.com> References: <20130905120111.4900aa60@gandalf.local.home> <5229C8F7.7060000@hitachi.com> X-Mailer: Claws Mail 3.9.2 (GTK+ 2.24.20; 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 Content-Length: 828 Lines: 23 On Fri, 06 Sep 2013 21:22:15 +0900 Masami Hiramatsu wrote: > > And AFAICS, the tracepoint (on which the syscall tracer based) > call-site uses rcu_read_lock_sched_notrace() instead of rcu_read_lock(), > in that case, I think we should use synchronize_sched(). is that wrong? > Ah, no, you are correct. I was thinking that the tracepoints used rcu_read_lock(), but looking at the code, it's rcu_read_lock_sched(). Thus a synchronize_sched() *is* required. Thanks, and please ignore my other comments about using "synchronize_rcu()". -- Steve -- 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/