lkml.org 
[lkml]   [2011]   [Apr]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] perf: Allow set output buffer for tasks in the same thread group
From
Date
On Mon, 2011-04-25 at 01:05 +0800, Peter Zijlstra wrote:
> On Sun, 2011-04-24 at 22:57 +0800, Lin Ming wrote:
> > Currently, kernel only allows an event to redirect its output to other
> > events of the same task.
> >
> > This causes PERF_EVENT_IOC_SET_OUTPUT ioctl fails when an event is
> > trying to redirect its output to other events in the same thread group.
>
> Which is exactly what it should do, you should never be allowed to
> redirect your events to that of another task, since that other task
> might be running on another CPU.
>
> The buffer code strictly assumes no concurrency, therefore its either
> one task or one CPU.

Well, this is not the right fix, then the perf tool code need to be
fixed.




\
 
 \ /
  Last update: 2011-04-25 15:43    [W:0.078 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site