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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@elte.hu>, Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH 4/4] ring-buffer: change WARN_ON from checking preempt_count to preemptible
Date: Fri, 08 May 2009 00:32:54 -0400	[thread overview]
Message-ID: <20090508043331.726786617@goodmis.org> (raw)
In-Reply-To: 20090508043250.372421144@goodmis.org

[-- Attachment #1: 0004-ring-buffer-change-WARN_ON-from-checking-preempt_co.patch --]
[-- Type: text/plain, Size: 964 bytes --]

From: Steven Rostedt <srostedt@redhat.com>

There's a WARN_ON in the ring buffer code that makes sure preemption
is disabled. It checks "!preempt_count()". But when CONFIG_PREEMPT is not
enabled, preempt_count() is always zero, and this will trigger the warning.

[ Impact: prevent false warning on non preemptible kernels ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/ring_buffer.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 3ae5ccf..3611706 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1688,7 +1688,7 @@ void ring_buffer_discard_commit(struct ring_buffer *buffer,
 	 * committed yet. Thus we can assume that preemption
 	 * is still disabled.
 	 */
-	RB_WARN_ON(buffer, !preempt_count());
+	RB_WARN_ON(buffer, preemptible());
 
 	cpu = smp_processor_id();
 	cpu_buffer = buffer->buffers[cpu];
-- 
1.6.2.4

-- 

  parent reply	other threads:[~2009-05-08  4:34 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-08  4:32 [PATCH 0/4] [GIT PULL] tracing/ring-buffer: updates for tip Steven Rostedt
2009-05-08  4:32 ` [PATCH 1/4] tracing: have menu default enabled when kernel debug is configured Steven Rostedt
2009-05-08  4:32 ` [PATCH 2/4] ring-buffer: only periodically call cond_resched to ring-buffer-benchmark Steven Rostedt
2009-05-08  4:32 ` [PATCH 3/4] ring-buffer: add total count in ring-buffer-benchmark Steven Rostedt
2009-05-08  4:52   ` Andrew Morton
2009-05-08 10:52     ` Steven Rostedt
2009-05-08  4:32 ` Steven Rostedt [this message]
2009-05-08  4:54   ` [PATCH 4/4] ring-buffer: change WARN_ON from checking preempt_count to preemptible Andrew Morton
2009-05-08 10:53     ` Steven Rostedt
2009-05-08 11:31       ` Ingo Molnar
2009-05-08 16:56       ` Andrew Morton
2009-05-08 17:23         ` Steven Rostedt
2009-05-08 11:30 ` [PATCH 0/4] [GIT PULL] tracing/ring-buffer: updates for tip Ingo Molnar

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