From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934409AbZIEAEH (ORCPT ); Fri, 4 Sep 2009 20:04:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934059AbZIEABV (ORCPT ); Fri, 4 Sep 2009 20:01:21 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:44564 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934011AbZIEABT (ORCPT ); Fri, 4 Sep 2009 20:01:19 -0400 Message-Id: <20090905000120.748914637@goodmis.org> References: <20090904235527.520961911@goodmis.org> User-Agent: quilt/0.46-1 Date: Fri, 04 Sep 2009 19:55:29 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Frederic Weisbecker , Arnaldo Carvalho de Melo Subject: [PATCH 02/18] ring-buffer: do not swap buffers during a commit Content-Disposition: inline; filename=0002-ring-buffer-do-not-swap-buffers-during-a-commit.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steven Rostedt If a commit is taking place on a CPU ring buffer, do not allow it to be swapped. Return -EBUSY when this is detected instead. Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 11 +++++++++-- 1 files changed, 9 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 79d6012..2878bd4 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3519,16 +3519,23 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, atomic_inc(&cpu_buffer_a->record_disabled); atomic_inc(&cpu_buffer_b->record_disabled); + ret = -EBUSY; + if (local_read(&cpu_buffer_a->committing)) + goto out_dec; + if (local_read(&cpu_buffer_b->committing)) + goto out_dec; + buffer_a->buffers[cpu] = cpu_buffer_b; buffer_b->buffers[cpu] = cpu_buffer_a; cpu_buffer_b->buffer = buffer_a; cpu_buffer_a->buffer = buffer_b; + ret = 0; + +out_dec: atomic_dec(&cpu_buffer_a->record_disabled); atomic_dec(&cpu_buffer_b->record_disabled); - - ret = 0; out: return ret; } -- 1.6.3.3 --