Re: [PATCH] perf tools: Do not fail on processing out of order event

From: Jiri Olsa
Date: Thu Nov 27 2014 - 09:23:58 EST


On Thu, Nov 27, 2014 at 12:16:26PM -0200, Arnaldo Carvalho de Melo wrote:
> Em Thu, Nov 27, 2014 at 03:07:07PM +0100, Jiri Olsa escreveu:
> > On Thu, Nov 27, 2014 at 11:53:00AM -0200, Arnaldo Carvalho de Melo wrote:
> > > Em Thu, Nov 27, 2014 at 11:56:03AM +0100, Ingo Molnar escreveu:
> > > > Arnaldo, I suppose the fix will go upstream via your tree, as a
> > > > pull request for v3.18 fixes?
>
> > > Right, I can do that.
>
> > > And I agree with the "expected" for events that are out of the current
> > > reordering window, i.e. we can't insert something into previous windows,
> > > so those are, humm, what would be a good name:
> > > stats->out_of_reordering_window, while stats->reordered, would be for
> > > events that were found out of order, but were successfully sorted as
> > > part of a flush operation, right?
>
> > the forced flush is when we find out we crossed the allowed allocation
> > space for the samples queue.. so we take the half of the sorted queue
> > and flush it.. for this case we break the flushing logic and we might
>
> Well, we make it more likely than without a forced flush to find out of
> order events, because the window suddenly became smaller, its like we
> found a FLUSH event right there, no?

yep, still I dont see the need to count those 2 cases separately,
both these types (of out of order event) have same implications
for the report

jirka

>
> > (probably just in theory) get out of order events
>
> > but IMO both cases of out of order event are equal.. we dont do
> > anything special for forced flushed AFAIK
>
> - Arnaldo
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