On 03/12/2013 04:48 PM, Ingo Molnar wrote: [snip] >>> >>> Instrumentation/stats/profiling will also double check the correctness of >>> this data: if developers/users start relying on the work metric as a >>> substitute benchmark number, then app writers will have an additional >>> incentive to make them correct. >> >> I see, I could not figure out how to wisely using the info currently, >> but I have the feeling that it will make scheduler very different ;-) >> >> May be we could implement the API and get those info ready firstly >> (along with the new sched-pipe which provide work tick info), then think >> about the way to use them in scheduler, is there any patches on the way? > > Absolutely. > > Beyond the new prctl no new API is needed: a perf soft event could be > added, and/or a tracepoint. Then perf stat and perf record could be used > with it. 'perf bench' could be extended to generate the work tick in its > 'perf bench sched ...' workloads - and for 'perf bench mem numa' as well.
Nice :) > > vsyscall-accelerating it could be a separate, more complex step: it needs > a per thread writable vsyscall data area to make the overhead to > applications near zero. Performance critical apps won't call an extra > syscall. If it's really bring benefit, I think they will consider about it, whatever, that's the developer/users decision, what we need to do is just make the stuff attractively. Regards, Michael Wang > > Thanks, > > Ingo > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
