Messages in this thread | | | Date | Thu, 17 Jul 2014 10:09:43 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH] perf stat: Pass PERF_STAT_RUN environment variable for each run |
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Em Thu, Jul 17, 2014 at 10:40:11AM +0200, Peter Zijlstra escreveu: > On Thu, Jul 17, 2014 at 05:31:14PM +0900, Namhyung Kim wrote: > > On Thu, Jul 17, 2014 at 5:26 PM, Peter Zijlstra <peterz@infradead.org> wrote: > > > On Thu, Jul 17, 2014 at 05:21:06PM +0900, Namhyung Kim wrote: > > >> When perf stat runs multiple times via -r option, it's sometimes > > >> useful for a workload to know which run it executing. So pass new > > >> PERF_STAT_RUN environment variable to the workload for each run > > >> (starting from 1).
> > > This seems counter intuitive, runs should be _identical_ otherwise > > > there's no point. That means the workload should very much _not_ know > > > these things.
> > But I think it can be useful if a workload wants to save logfiles > > based on the iteration number for example. If it doesn't want, it can > > just ignore. :)
> That's the wrong way around. Also, there's --pre and --post hooks to > preserve logfiles if you really have to do that kind of thing.
Agreed, one can script this using --pre or --post if needed.
- Arnaldo
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