Re: [PATCH 1/3] perf: add context field to perf_event

Avi Kivity
2011-07-12T09:36:25Z

On 07/12/2011 12:31 PM, Peter Zijlstra wrote:
> >
> > But it means that 'current' is not set to the right value. If the
> > function depends on it, then it will misbehave. And in fact
> > preempt_notifier_register(), which is the function we want to call here,
> > does depend on current.
> >
> > Of course we need to find more users for this, but I have a feeling this
> > will be generally useful. The alternative is to keep adding bits to
> > thread_info::flags.
>
> Using TIF_bits sounds like a much better solution for this, wakeups are
> really rather expensive and its best to avoid extra if at all possible.
>

We do need a way to make the task look at them.

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.