Re: [PATCH 14/26] trace: Convert various locks to raw_spinlock

Frederic Weisbecker
2010-01-17T13:00:52Z

On Wed, Jan 13, 2010 at 07:09:22PM +0100, John Kacur wrote:
>
>
> On Wed, 13 Jan 2010, Steven Rostedt wrote:
>
> > On Wed, 2010-01-13 at 16:36 +0100, John Kacur wrote:
> > >
> > > On Wed, 13 Jan 2010, Steven Rostedt wrote:
> >
> > > >
> > > Thanks for the review Steve and Frederic - I'll spin a new patch that
> > > doesn't convert tracing_start_lock.
> > >
> > > However, let's give it some good testing in preempt-rt, because we may
> > > have forgotten over time, why we converted these locks.
> >
> > Well, I think we just never unconverted them :-) I think we took the
> > paranoid approach and converted all locks in the trace directory to raw.
> > In fact, I think I even had a script to do it.
> >
> > -- Steve
>
> Okay, here is the new version of the patch.
> Frederic and Steve, can I have Acked-bys before I push to git?
>
> Thanks
>
> From ee03cc607493e58f34bf93afa2b8a23da5510927 Mon Sep 17 00:00:00 2001
> From: John Kacur <jkacur@redhat.com>
> Date: Sun, 10 Jan 2010 03:09:48 +0100
> Subject: [PATCH] trace: Convert reader_lock and max_trace_lock to raw_spinlocks
>
> Convert reader_lock and max_trace_lock to raw_spinlock.
> These locks cannot sleep in preempt-rt because they are called with
> interrupts disabled. This should have zero-impact on mainline.
>
> See also: 87654a70523a8c5baadcbbc07d80cbae8f912837
>
> Signed-off-by: John Kacur <jkacur@redhat.com>

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>