From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750815AbcBECku (ORCPT ); Thu, 4 Feb 2016 21:40:50 -0500 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.229]:13703 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750721AbcBECks (ORCPT ); Thu, 4 Feb 2016 21:40:48 -0500 Date: Thu, 4 Feb 2016 21:40:45 -0500 From: Steven Rostedt To: Dmitry Safonov <0x7f454c46@gmail.com> Cc: mingo@redhat.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org Subject: Re: [RFC] trace_irqsoff: remove redundant reset per-CPU buff Message-ID: <20160204214045.1d6c2893@grimm.local.home> In-Reply-To: <1445278226-16187-1-git-send-email-0x7f454c46@gmail.com> References: <1445278226-16187-1-git-send-email-0x7f454c46@gmail.com> X-Mailer: Claws Mail 3.13.0 (GTK+ 2.24.29; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.118:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 19 Oct 2015 21:10:26 +0300 Dmitry Safonov <0x7f454c46@gmail.com> wrote: > There is no reason to do it twice: from commit b6f11df26fdc28 > ("trace: Call tracing_reset_online_cpus before tracer->init()") > resetting of per-CPU buffers done before tracer->init() call. > > tracer->init() calls {irqs,preempt,preemptirqs}off_tracer_init() and it > calls __irqsoff_tracer_init(), which resets per-CPU ringbuffer second > time. > It's slowpath, but anyway. Bah, I said I'd look at this and I did. But never added it to my queue. It's not a big deal as this is the slow path but it makes sense. I knew there was a patch from you to get but saw the TP_ARGS redefining patch and thought that was it. I Cc'd myself on this to make sure I see it again. -- Steve > > Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> > --- > kernel/trace/trace_irqsoff.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c > index 8523ea345f2b1a..4ebcb8bfaced24 100644 > --- a/kernel/trace/trace_irqsoff.c > +++ b/kernel/trace/trace_irqsoff.c > @@ -612,7 +612,6 @@ static int __irqsoff_tracer_init(struct trace_array *tr) > irqsoff_trace = tr; > /* make sure that the tracer is visible */ > smp_wmb(); > - tracing_reset_online_cpus(&tr->trace_buffer); > > ftrace_init_array_ops(tr, irqsoff_tracer_call); >