2012-05-24 16:32:17

by Borislav Petkov

Subject: Re: [PATCH] ftrace: Remove a superfluous check

Yo Steve,

want to pick this one up? It still applies cleanly to current linus.

Thanks.

On Thu, Mar 29, 2012 at 07:11:40PM +0200, Borislav Petkov wrote:
> On Thu, Mar 29, 2012 at 07:03:23PM +0200, John Kacur wrote:
> > If you're going to do this, then you can drop the label too.
>
> Jahaa... thanks.
>
> Here's an updated patch:
>
> --
> From 135c25a609739bbdf1c33e62119517b47f0e1d07 Mon Sep 17 00:00:00 2001
> From: Borislav Petkov <[email protected]>
> Date: Thu, 29 Mar 2012 18:41:15 +0200
> Subject: [PATCH] ftrace: Remove a superfluous check
>
> register_ftrace_function() checks ftrace_disabled and calls
> __register_ftrace_function which does it again.
>
> Drop the first check and add the unlikely hint to the second one. Also,
> drop the label as John correctly notices.
>
> No functional change.
>
> Cc: John Kacur <[email protected]>
> Signed-off-by: Borislav Petkov <[email protected]>
> ---
> kernel/trace/ftrace.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 867bd1dd2dd0..0df8f8088ffe 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -311,7 +311,7 @@ static int remove_ftrace_list_ops(struct ftrace_ops **list,
>
> static int __register_ftrace_function(struct ftrace_ops *ops)
> {
> - if (ftrace_disabled)
> + if (unlikely(ftrace_disabled))
> return -ENODEV;
>
> if (FTRACE_WARN_ON(ops == &global_ops))
> @@ -4304,16 +4304,12 @@ int register_ftrace_function(struct ftrace_ops *ops)
>
> mutex_lock(&ftrace_lock);
>
> - if (unlikely(ftrace_disabled))
> - goto out_unlock;
> -
> ret = __register_ftrace_function(ops);
> if (!ret)
> ret = ftrace_startup(ops, 0);
>
> -
> - out_unlock:
> mutex_unlock(&ftrace_lock);
> +
> return ret;
> }
> EXPORT_SYMBOL_GPL(register_ftrace_function);
> --
> 1.7.9.3.362.g71319

--
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
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2012-05-24 16:42:41

by Steven Rostedt

Subject: Re: [PATCH] ftrace: Remove a superfluous check

On Thu, 2012-05-24 at 18:32 +0200, Borislav Petkov wrote:
> Yo Steve,
>
> want to pick this one up? It still applies cleanly to current linus.

I actually have it in my 3.6 queue. It didn't look like it was urgent
for 3.5. Is it?

-- Steve

>
> Thanks.
>
> On Thu, Mar 29, 2012 at 07:11:40PM +0200, Borislav Petkov wrote:
> > On Thu, Mar 29, 2012 at 07:03:23PM +0200, John Kacur wrote:
> > > If you're going to do this, then you can drop the label too.
> >
> > Jahaa... thanks.
> >
> > Here's an updated patch:
> >
> > --
> >

2012-05-24 17:05:10

by Borislav Petkov

Subject: Re: [PATCH] ftrace: Remove a superfluous check

On Thu, May 24, 2012 at 12:41:50PM -0400, Steven Rostedt wrote:
> On Thu, 2012-05-24 at 18:32 +0200, Borislav Petkov wrote:
> > Yo Steve,
> >
> > want to pick this one up? It still applies cleanly to current linus.
>
> I actually have it in my 3.6 queue. It didn't look like it was urgent
> for 3.5. Is it?

Nah, I was just cleaning up my mbox and saw it.

Thanks.

--
Regards/Gruss,
Boris.