From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754244AbbJSSJr (ORCPT ); Mon, 19 Oct 2015 14:09:47 -0400 Received: from mail-lf0-f42.google.com ([209.85.215.42]:35046 "EHLO mail-lf0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752565AbbJSSJq (ORCPT ); Mon, 19 Oct 2015 14:09:46 -0400 From: Dmitry Safonov <0x7f454c46@gmail.com> To: rostedt@goodmis.org, mingo@redhat.com Cc: linux-kernel@vger.kernel.org, Dmitry Safonov <0x7f454c46@gmail.com> Subject: [RFC] trace_irqsoff: remove redundant reset per-CPU buff Date: Mon, 19 Oct 2015 21:10:26 +0300 Message-Id: <1445278226-16187-1-git-send-email-0x7f454c46@gmail.com> X-Mailer: git-send-email 2.6.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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); -- 2.6.1