Messages in this thread | | | Date | Mon, 31 May 2010 10:00:49 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] tracing: Add task activate/deactivate tracepoints |
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* Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, 2010-05-28 at 16:26 +0200, Frederic Weisbecker wrote: > > We have various tracepoints that tell us when a task is going to > > be enqueued in a runqueue: fork, wakeup, migrate. > > > > But they don't always provide us the level of information necessary > > to know what is actually in which runqueue, precisely because the > > migrate event is only fired if the task is queued on another > > cpu than its previous one. So we don't always know where a waking up > > task goes. > > > > And moreover we don't have events that tells a task goes to sleep, > > and even that wouldn't cover every cases when a task is dequeued. > > > > So bring these two new tracepoints to get informations about the > > load of each runqueues. > > NAK, aside from a few corner cases wakeup and sleep are the important > points. > > The activate and deactivate functions are implementation details.
Frederic, can you show us a concrete example of where we dont know what is going on due to inadequate instrumentation? Can we fix that be extending the existing tracepoints?
Ingo
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