Re: Q: perf_event && event->owner

[Oleg Nesterov]

On 11/09, Peter Zijlstra wrote:
>
> On Tue, 2010-11-09 at 16:57 +0100, Oleg Nesterov wrote:
> >
> > If the creator of perf_event dies, nobody can use its ->perf_event_list
> > anyway. What is the point to keep the reference to the dead task_struct
> > and preserve this ->perf_event_list?
>
> But when the owner dies it will close all its fds, which means it will
> clear its tsk->perf_event_list, no? (With exception of the case where
> the fd was passed through a unix-socket to another process).

fork(), pthread_create(). Only __fput() calls ->release, when the last
reference to file goes away.

And ptrace(), it doesn't use sys_perf_event_open() to create the event.

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/