lkml.org 
[lkml]   [2015]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH V2 1/6] perf,core: allow invalid context events to be part of sw/hw groups
> Even if you ignore the fundamental semantics of groups, there are other
> problems with allowing shared contexts:
>
> * The *_txn functions only get called on the group leader's PMU. If your
> system PMU has these functions, they are not called.
>
> * Event rotation is per ctx, but now you could have some events in a CPU
> PMU's context, and some in the uncore PMU's context. So those can race
> with each other.
>
> * Throttling is also per-context. So those can race with each other too.

There's also a break down of behaviour: events in the uncore context
will get migrated to another CPU in the event of a hot unplug, while
events that are grouped with CPU events (and hence live in the CPU
context) will be destroyed.

Mark.


\
 
 \ /
  Last update: 2015-04-16 19:21    [W:0.161 / U:30.780 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site