[PATCH 0/1] ring-buffer fix for 2.6.28

[PATCH 0/1] ring-buffer fix for 2.6.28

[Steven Rostedt]

The following patch needs to go into 2.6.28. It protects against
a recursion race that can happen when the scheduler is traced.

The following patches are in:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git

    branch: devel


Lai Jiangshan (1):
      ring-buffer: prevent recursion

----
 kernel/trace/ring_buffer.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

[PATCH 1/1] ring-buffer: prevent recursion

[Steven Rostedt]

[-- Attachment #1: 0001-ring-buffer-prevent-recursion.patch --]
[-- Type: text/plain, Size: 772 bytes --]

From: Lai Jiangshan <laijs@cn.fujitsu.com>

Impact: fix to recursion in function tracer with schedule

If the resched flag was set before we entered, then don't reschedule.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
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 f780e95..668bbb5 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1215,7 +1215,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
 
  out:
 	if (resched)
-		preempt_enable_notrace();
+		preempt_enable_no_resched_notrace();
 	else
 		preempt_enable_notrace();
 	return NULL;
-- 
1.5.6.5

-- 

Re: [PATCH 0/1] ring-buffer fix for 2.6.28

[Randy Dunlap]

Steven Rostedt wrote:
> The following patch needs to go into 2.6.28. It protects against
> a recursion race that can happen when the scheduler is traced.
> 
> The following patches are in:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> 
>     branch: devel
> 
> 
> Lai Jiangshan (1):
>       ring-buffer: prevent recursion
> 
> ----
>  kernel/trace/ring_buffer.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)

Is there something about git that causes (or forces) the use of
patch 0/1 followed by patch 1/1?  I find it terribly unwanted.

thanks,
-- 
~Randy

Re: [PATCH 0/1] ring-buffer fix for 2.6.28

[Steven Rostedt]

On Wed, 26 Nov 2008, Randy Dunlap wrote:

> Steven Rostedt wrote:
> > The following patch needs to go into 2.6.28. It protects against
> > a recursion race that can happen when the scheduler is traced.
> > 
> > The following patches are in:
> > 
> >   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> > 
> >     branch: devel
> > 
> > 
> > Lai Jiangshan (1):
> >       ring-buffer: prevent recursion
> > 
> > ----
> >  kernel/trace/ring_buffer.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> Is there something about git that causes (or forces) the use of
> patch 0/1 followed by patch 1/1?  I find it terribly unwanted.
> 

It's my scripts that post. I should probably modify it so that if there is 
only one patch, that I append it to the prolog instead, and mail it out 
the old way. My scripts pull the patches out of my git tree and use quilt 
top post. I know git has a way to do that too, but I have not set that up.

-- Steve

Re: [PATCH 0/1] ring-buffer fix for 2.6.28

[Ingo Molnar]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> The following patch needs to go into 2.6.28. It protects against a 
> recursion race that can happen when the scheduler is traced.

thanks, i've applied Lai's patch from email to tip/tracing/urgent.

	Ingo