Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 27 Jun 2024 20:11:14 -0700 | From | Namhyung Kim <> | Subject | Re: [PATCH v2] perf sched replay: Fix -r/--repeat command line option for infinity |
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On Fri, Jun 28, 2024 at 08:00:14AM +0530, Madadi Vineeth Reddy wrote: > On 21/06/24 22:49, Madadi Vineeth Reddy wrote: > > Currently, the -r/--repeat option accepts values from 0 and complains > > for -1. The help section specifies: > > -r, --repeat <n> repeat the workload replay N times (-1: infinite) > > > > The -r -1 option raises an error because replay_repeat is defined as > > an unsigned int. > > > > In the current implementation, the workload is repeated n times when > > -r <n> is used, except when n is 0. > > > > When -r is set to 0, the workload is also repeated once. This happens > > because when -r=0, the run_one_test function is not called. (Note that > > mutex unlocking, which is essential for child threads spawned to emulate > > the workload, happens in run_one_test.) However, mutex unlocking is > > still performed in the destroy_tasks function. Thus, -r=0 results in the > > workload running once coincidentally. > > > > To clarify and maintain the existing logic for -r >= 1 (which runs the > > workload the specified number of times) and to fix the issue with infinite > > runs, make -r=0 perform an infinite run. > > > > Signed-off-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com> > > Reviewed-by: James Clark <james.clark@arm.com> > > > > Hi all, > Any suggestions/comments on this patch?
I think the original intention was to set replay_repeat to UINT_MAX using -1. But it seems to refuse the negative number now.
Maybe you can simply set it to UNIT_MAX for -r 0.
Thanks, Namhyung
> > --- > > Changes in v2: > > - Kept the existing 'for' loop and added a condition for infinite > > looping. (James Clark) > > - This change also ensures that integer overflow doesn't occur when > > 'replay_repeat' is zero. > > - Add Reviewed-by tag from James Clark. > > - Rebase against perf-tools-next commit 788c5160526a ("perf vendor > > events: Add westmereex counter information") > > - Link to v1: https://lore.kernel.org/all/20240618112907.15131-1-vineethr@linux.ibm.com/ > > > > tools/perf/Documentation/perf-sched.txt | 7 +++++++ > > tools/perf/builtin-sched.c | 11 ++++++++--- > > 2 files changed, 15 insertions(+), 3 deletions(-) > > > > diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt > > index a216d2991b19..f1be8f0b249e 100644 > > --- a/tools/perf/Documentation/perf-sched.txt > > +++ b/tools/perf/Documentation/perf-sched.txt > > @@ -202,6 +202,13 @@ OPTIONS for 'perf sched timehist' > > --state:: > > Show task state when it switched out. > > > > +OPTIONS for 'perf sched replay' > > +------------------------------ > > + > > +-r:: > > +--repeat <n>:: > > + repeat the workload n times (0: infinite). Default is 10. > > + > > SEE ALSO > > -------- > > linkperf:perf-record[1] > > diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c > > index 8cdf18139a7e..51b3dea404bc 100644 > > --- a/tools/perf/builtin-sched.c > > +++ b/tools/perf/builtin-sched.c > > @@ -3383,8 +3383,13 @@ static int perf_sched__replay(struct perf_sched *sched) > > sched->thread_funcs_exit = false; > > create_tasks(sched); > > printf("------------------------------------------------------------\n"); > > - for (i = 0; i < sched->replay_repeat; i++) > > - run_one_test(sched); > > + if (sched->replay_repeat == 0) { > > + while (1) > > + run_one_test(sched); > > + } else { > > + for (i = 0; i < sched->replay_repeat; i++) > > + run_one_test(sched); > > + } > > > > sched->thread_funcs_exit = true; > > destroy_tasks(sched); > > @@ -3548,7 +3553,7 @@ int cmd_sched(int argc, const char **argv) > > }; > > const struct option replay_options[] = { > > OPT_UINTEGER('r', "repeat", &sched.replay_repeat, > > - "repeat the workload replay N times (-1: infinite)"), > > + "repeat the workload replay N times (0: infinite)"), > > OPT_PARENT(sched_options) > > }; > > const struct option map_options[] = { >
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