Re: [PATCH] kprobes,x86: disable irq durinr optimized callback

From: Jiri Olsa
Date: Tue May 10 2011 - 07:39:49 EST


On Tue, May 10, 2011 at 12:40:19PM +0200, Ingo Molnar wrote:
>
> * Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> > + local_irq_save(flags);
> > preempt_disable();
> > if (kprobe_running()) {
> > kprobes_inc_nmissed_count(&op->kp);
> > @@ -1208,6 +1210,7 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op,
> > __this_cpu_write(current_kprobe, NULL);
> > }
> > preempt_enable_no_resched();
> > + local_irq_restore(flags);
>
> irq-disable is synonymous to preempt disable so the preempt_disable()/enable()
> pair looks like superfluous overhead.

yes, there's correct patch already in the list here:
http://marc.info/?l=linux-kernel&m=130382756829695&w=2

thanks,
jirka

>
> Thanks,
>
> Ingo
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