Re: [PATCH v2] core, x86: Add user return notifiers

Avi Kivity
2009-09-22T17:06:01Z

On 09/22/2009 07:55 PM, Peter Zijlstra wrote:
>> If you're using lockdep, surely that's not your biggest worry?
>>
> No, but that's all under #ifdef and fully disappears when not enabled.
> Generic return-tu-user notifiers don't sound like they will though.
>

They will if not selected. If selected and not armed, they will have
zero runtime impact since they piggyback on existing branches
(_TIF_DO_NOTIFY_MASK and near relatives). If selected and armed they'll
cause __switch_to_xtra() on every context switch and do_notity_resume()
on syscall exit until disarmed, but then you've asked for it.

--
error compiling committee.c: too many arguments to function