Em Fri, Mar 19, 2021 at 04:14:42PM +0000, Song Liu escreveu: > > On Mar 19, 2021, at 8:58 AM, Namhyung Kim <namhy...@kernel.org> wrote: > > On Sat, Mar 20, 2021 at 12:35 AM Arnaldo Carvalho de Melo <a...@kernel.org> > > wrote: > >> Em Fri, Mar 19, 2021 at 09:54:59AM +0900, Namhyung Kim escreveu: > >>> On Fri, Mar 19, 2021 at 9:22 AM Song Liu <songliubrav...@fb.com> wrote: > >>>>> On Mar 18, 2021, at 5:09 PM, Arnaldo <arnaldo.m...@gmail.com> wrote: > >>>>> On March 18, 2021 6:14:34 PM GMT-03:00, Jiri Olsa <jo...@redhat.com> > >>>>> wrote: > >>>>>> On Thu, Mar 18, 2021 at 03:52:51AM +0000, Song Liu wrote: > >>>>>>> perf stat -C 1,3,5 107.063 [sec] > >>>>>>> perf stat -C 1,3,5 --bpf-counters 106.406 [sec]
> >>>>>> I can't see why it's actualy faster than normal perf ;-) > >>>>>> would be worth to find out > >>>>> Isn't this all about contended cases? > >>>> Yeah, the normal perf is doing time multiplexing; while --bpf-counters > >>>> doesn't need it. > >>> Yep, so for uncontended cases, normal perf should be the same as the > >>> baseline (faster than the bperf). But for contended cases, the bperf > >>> works faster. > >> The difference should be small enough that for people that use this in a > >> machine where contention happens most of the time, setting a > >> ~/.perfconfig to use it by default should be advantageous, i.e. no need > >> to use --bpf-counters on the command line all the time. > >> So, Namhyung, can I take that as an Acked-by or a Reviewed-by? I'll take > >> a look again now but I want to have this merged on perf/core so that I > >> can work on a new BPF SKEL to use this: > > I have a concern for the per cpu target, but it can be done later, so > > Acked-by: Namhyung Kim <namhy...@kernel.org> > >> https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/log/?h=tmp.bpf/bpf_perf_enable > > Interesting! Actually I was thinking about the similar too. :) > > Hi Namhyung, Jiri, and Arnaldo, > > Thanks a lot for your kind review. > > Here is updated 3/3, where we use perf-bench instead of stressapptest. I had to apply this updated 3/3 manually, as there was some munging, its all now at: https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/log/?h=tmp.perf/core Please take a look at the "Committer testing" section I added to the main patch, introducing bperf: https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/commit/?h=tmp.perf/core&id=7fac83aaf2eecc9e7e7b72da694c49bb4ce7fdfc And check if I made any mistake or if something else could be added. It'll move to perf/core after my set of automated tests finishes. - Arnaldo
