lkml.org 
[lkml]   [2009]   [Oct]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH RFC] sched: add notifier for process migration

* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> @@ -1981,6 +1989,12 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
> #endif
> perf_swcounter_event(PERF_COUNT_SW_CPU_MIGRATIONS,
> 1, 1, NULL, 0);
> +
> + tmn.task = p;
> + tmn.from_cpu = old_cpu;
> + tmn.to_cpu = new_cpu;
> +
> + atomic_notifier_call_chain(&task_migration_notifier, 0, &tmn);

We already have one event notifier there - look at the
perf_swcounter_event() callback. Why add a second one for essentially
the same thing?

We should only put a single callback there - a tracepoint defined via
TRACE_EVENT() - and any secondary users can register a callback to the
tracepoint itself.

There's many similar places in the kernel - with notifier chains and
also with a need to get tracepoints there. The fastest (and most
consistent) solution is to add just a single event callback facility.

Ingo


\
 
 \ /
  Last update: 2009-10-14 09:15    [from the cache]
©2003-2011 Jasper Spaans