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

Joerg Roedel
2011-07-12T09:48:24Z

On Tue, Jul 12, 2011 at 12:44:17PM +0300, Avi Kivity wrote:
> On 07/12/2011 12:41 PM, Joerg Roedel wrote:
>> > 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.
>>
>> I would rather vote for Avi's solution too. Such a functionality is very
>> helpful for LWP-perf integration as well (because we need a way to call
>> do_mmap for a task != current).
>>
>
> It's not needed for that. See use_mm() (caller must be a kernel thread).

But in our case the caller would be the process that wants to count, not
a kernel thread.

Joerg