From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754636Ab2GIOkH (ORCPT ); Mon, 9 Jul 2012 10:40:07 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:38307 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754503Ab2GIOiZ (ORCPT ); Mon, 9 Jul 2012 10:38:25 -0400 Message-Id: <20120709143120.057461094@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 09 Jul 2012 15:31:39 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Vaibhav Nagarnaik , Frederic Weisbecker , Ingo Molnar , Laurent Chavey , Justin Teravest , David Sharp , Steven Rostedt Subject: [ 23/48] tracing: change CPU ring buffer state from tracing_cpumask In-Reply-To: <20120709143116.348975190@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vaibhav Nagarnaik commit 71babb2705e2203a64c27ede13ae3508a0d2c16c upstream. According to Documentation/trace/ftrace.txt: tracing_cpumask: This is a mask that lets the user only trace on specified CPUS. The format is a hex string representing the CPUS. The tracing_cpumask currently doesn't affect the tracing state of per-CPU ring buffers. This patch enables/disables CPU recording as its corresponding bit in tracing_cpumask is set/unset. Link: http://lkml.kernel.org/r/1336096792-25373-3-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Laurent Chavey Cc: Justin Teravest Cc: David Sharp Signed-off-by: Vaibhav Nagarnaik Signed-off-by: Steven Rostedt Signed-off-by: Ben Hutchings --- kernel/trace/trace.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0ed4df0..08a08ba 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2669,10 +2669,12 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, if (cpumask_test_cpu(cpu, tracing_cpumask) && !cpumask_test_cpu(cpu, tracing_cpumask_new)) { atomic_inc(&global_trace.data[cpu]->disabled); + ring_buffer_record_disable_cpu(global_trace.buffer, cpu); } if (!cpumask_test_cpu(cpu, tracing_cpumask) && cpumask_test_cpu(cpu, tracing_cpumask_new)) { atomic_dec(&global_trace.data[cpu]->disabled); + ring_buffer_record_enable_cpu(global_trace.buffer, cpu); } } arch_spin_unlock(&ftrace_max_lock);