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

Avi Kivity
2009-09-22T14:46:24Z

On 09/22/2009 05:32 PM, Ingo Molnar wrote:
> * Avi Kivity<avi@redhat.com> wrote:
>
>
>> On 09/19/2009 09:40 AM, Avi Kivity wrote:
>>
>>> Add a general per-cpu notifier that is called whenever the kernel is
>>> about to return to userspace. The notifier uses a thread_info flag
>>> and existing checks, so there is no impact on user return or context
>>> switch fast paths.
>>>
>>>
>> Ingo/Peter?
>>
> Would be nice to convert some existing open-coded return-to-user-space
> logic to this facility. One such candidate would be lockdep_sys_exit?
>

I only implemented this for x86, while lockdep is arch independent. If
arch support is added, it should be trivial.

I think perf counters could use preempt notifiers though, these are arch
independent.

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