Em Sat, Sep 26, 2020 at 11:10:46PM +0900, Namhyung Kim escreveu: > Hi Joel, > > On Sat, Sep 26, 2020 at 8:56 AM Joel Fernandes (Google) > <j...@joelfernandes.org> wrote: > > > > perf sched latency is really useful at showing worst-case latencies that > > task > > encountered since wakeup. However it shows only the end of the latency. > > Often > > times the start of a latency is interesting as it can show what else was > > going > > on at the time to cause the latency. I certainly myself spending a lot of > > time > > backtracking to the start of the latency in "perf sched script" which > > wastes a > > lot of time. > > > > This patch therefore adds a new column "Max delay start". Considering this, > > also rename "Maximum delay at" to "Max delay end" as its easier to > > understand. > > Oh, I thought we print start time not the end time. I think it's better > to print start time but others may think differently. > > Actually we can calculate the start time from the end time and the > latency but it'd be convenient if the tool does that for us (as they are > printed in different units). Then the remaining concern is the screen > width (of 114 or 115?) but I think it should be fine for most of us. > > Acked-by: Namhyung Kim <namhy...@kernel.org>
Thanks, applied. - Arnaldo > > Thanks > Namhyung > > > > > Signed-off-by: Joel Fernandes (Google) <j...@joelfernandes.org> > > > > > > --- > > A sample output can be seen after applying patch: > > https://hastebin.com/raw/ivinimaler > > > > tools/perf/builtin-sched.c | 24 ++++++++++++++---------- > > 1 file changed, 14 insertions(+), 10 deletions(-) > > > > diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c > > index 459e4229945e..2791da1fe5f7 100644 > > --- a/tools/perf/builtin-sched.c > > +++ b/tools/perf/builtin-sched.c > > @@ -130,7 +130,8 @@ struct work_atoms { > > struct thread *thread; > > struct rb_node node; > > u64 max_lat; > > - u64 max_lat_at; > > + u64 max_lat_start; > > + u64 max_lat_end; > > u64 total_lat; > > u64 nb_atoms; > > u64 total_runtime; > > @@ -1096,7 +1097,8 @@ add_sched_in_event(struct work_atoms *atoms, u64 > > timestamp) > > atoms->total_lat += delta; > > if (delta > atoms->max_lat) { > > atoms->max_lat = delta; > > - atoms->max_lat_at = timestamp; > > + atoms->max_lat_start = atom->wake_up_time; > > + atoms->max_lat_end = timestamp; > > } > > atoms->nb_atoms++; > > } > > @@ -1322,7 +1324,7 @@ static void output_lat_thread(struct perf_sched > > *sched, struct work_atoms *work_ > > int i; > > int ret; > > u64 avg; > > - char max_lat_at[32]; > > + char max_lat_start[32], max_lat_end[32]; > > > > if (!work_list->nb_atoms) > > return; > > @@ -1344,13 +1346,14 @@ static void output_lat_thread(struct perf_sched > > *sched, struct work_atoms *work_ > > printf(" "); > > > > avg = work_list->total_lat / work_list->nb_atoms; > > - timestamp__scnprintf_usec(work_list->max_lat_at, max_lat_at, > > sizeof(max_lat_at)); > > + timestamp__scnprintf_usec(work_list->max_lat_start, max_lat_start, > > sizeof(max_lat_start)); > > + timestamp__scnprintf_usec(work_list->max_lat_end, max_lat_end, > > sizeof(max_lat_end)); > > > > - printf("|%11.3f ms |%9" PRIu64 " | avg:%9.3f ms | max:%9.3f ms | > > max at: %13s s\n", > > + printf("|%11.3f ms |%9" PRIu64 " | avg:%8.3f ms | max:%8.3f ms | > > max start: %12s s | max end: %12s s\n", > > (double)work_list->total_runtime / NSEC_PER_MSEC, > > work_list->nb_atoms, (double)avg / NSEC_PER_MSEC, > > (double)work_list->max_lat / NSEC_PER_MSEC, > > - max_lat_at); > > + max_lat_start, max_lat_end); > > } > > > > static int pid_cmp(struct work_atoms *l, struct work_atoms *r) > > @@ -3118,7 +3121,8 @@ static void __merge_work_atoms(struct rb_root_cached > > *root, struct work_atoms *d > > list_splice(&data->work_list, &this->work_list); > > if (this->max_lat < data->max_lat) { > > this->max_lat = data->max_lat; > > - this->max_lat_at = data->max_lat_at; > > + this->max_lat_start = data->max_lat_start; > > + this->max_lat_end = data->max_lat_end; > > } > > zfree(&data); > > return; > > @@ -3157,9 +3161,9 @@ static int perf_sched__lat(struct perf_sched *sched) > > perf_sched__merge_lat(sched); > > perf_sched__sort_lat(sched); > > > > - printf("\n > > -----------------------------------------------------------------------------------------------------------------\n"); > > - printf(" Task | Runtime ms | Switches | > > Average delay ms | Maximum delay ms | Maximum delay at |\n"); > > - printf(" > > -----------------------------------------------------------------------------------------------------------------\n"); > > + printf("\n > > -------------------------------------------------------------------------------------------------------------------------------------------\n"); > > + printf(" Task | Runtime ms | Switches | Avg > > delay ms | Max delay ms | Max delay start | Max delay end > > |\n"); > > + printf(" > > -------------------------------------------------------------------------------------------------------------------------------------------\n"); > > > > next = rb_first_cached(&sched->sorted_atom_root); > > > > -- > > 2.28.0.709.gb0816b6eb0-goog -- - Arnaldo
