Em Tue, Sep 17, 2013 at 02:54:22PM +0900, Namhyung Kim escreveu: > Hi Ingo, > > On Sat, 14 Sep 2013 08:11:49 +0200, Ingo Molnar wrote: > > * Frederic Weisbecker <fweis...@gmail.com> wrote: > >> My patches and Namhyung's should improve the comm situation a lot but we > >> can't do much miracle. The only way would be perhaps to be able to limit > >> the deepness of the callchain branches. > >> > >> Now may be we can find other big contention point in perf. It's possible > >> we also have some endless loop somewhere. > > > > Well, it was the 100,000+ step linear list walk that was causing 90% of > > the slowness here. Namhyung's patch should dramatically improve that. I > > guess time for someone to post a combined tree so that it can be tested > > all together? > > I pushed combined tree to 'perf/callchain-v2' branch in my tree > > git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git
But you did it for some old tree, as I tried running it now and since my big perf.data file has PERF_RECORD_MMAP2 records, I can't try it with your branch, working on cherry picking those changesets, since a plain rebase didn't work. - Arnaldo > > Please note that I also pushed other versions (v[1-3]). The v1 is my > previous rbtree conversion patch, v2 adds Frederic's new comm > infrastructure series on top and v3 adds my revised patch to refer > current comm [1] on top of v2. > > I did my own test again among them. Test data is 400MB perf.data file > created by parallel kernel build. > > $ ls -lh perf.data.big > -rw-------. 1 namhyung namhyung 400M Sep 9 10:21 perf.data.big > > For more precise result, I changed cpufreq governor to 'performance' > > # echo performance > /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor > > and run perf report on the cpu. > > $ taskset -c 3 time -p perf --no-pager report --stdio -i perf.data.big > > /dev/null > > I ran it multiple times for each case and the results did not vary much. > > baseline v1 v2 v3 > ---------------------------------------------------------- > real 380.17 12.63 10.02 9.03 > user 378.86 11.95 9.66 8.69 > sys 0.70 0.65 0.33 0.34 > > > I also tried to cache latest result and reuse it when adding a callchain > (in callchain_append() function) but it only hits ~5% and did not help > the performance. > > Thanks, > Namhyung > > > [1] https://lkml.org/lkml/2013/9/16/565 -- 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/
