| Message ID | 20250123060443.31371-1-shichen@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | rt-tests: pip_stress: Add option --usleep | expand |
On Fri, Jan 24, 2025 at 9:06 AM Crystal Wood <crwood@redhat.com> wrote: > > On Thu, 2025-01-23 at 14:04 +0800, Shizhao Chen wrote: > > Different hardwares have different threasholds for usleep_val to > > reliably trigger an prio inversion, add option --usleep to allow > > specifying it at runtime, to facilitate testing of prio inheritance > > on different platforms. > > > > Signed-off-by: Shizhao Chen <shichen@redhat.com> > > --- > > src/pi_tests/pip_stress.8 | 6 +++++- > > src/pi_tests/pip_stress.c | 10 ++++++++-- > > 2 files changed, 13 insertions(+), 3 deletions(-) > > Hmm, looks like there was an earlier attempt (53956b6712fef1, > "pip_stress: parameterize usleep value to work-around platform issues") > that was missing the actual call to getopt... and then another commit > (1325cb7e9e3af08e, "Daniel Wagner <dwagner@suse.de>") that added getopt > but removed usleep -- while also adding a "-s" option that does nothing. > :-P Yeah I kinda stole the option from clark :) > > Some minor nits: > > > @@ -41,6 +42,9 @@ merely increase the time that the low priority process sleeps while > > holding the lock. (usleep); > > Also note that you have to run as a user with permission to change > > scheduling priorities. > > +.SH OPTIONS > > +.IP "\-u TIME,\-\-usleep=TIME" > > +Specify the sleep time of the low priority process. Defaults to 500(us). > > The unit should be part of the description, not the default: > > Specify the sleep time in usec of the low priority process. Defaults to > 500. I hesitated several times whether I should add the (us) at the end, your version looks much better, thanks! > > > - "-h --help Show this help menu.\n" > > + "-h --help Show this help menu.\n"\ > > + "-u TIME --usleep=TIME Specify the sleep time of the low priority process.\n"\ > > + " Defaults to 500(us).\n" > > ); > > Likewise here > > > + case 'u': > > + usleep_val = (useconds_t)strtoul(optarg, NULL, 10); > > + break; > > Why is this cast needed? It's not needed - just me being unfamiliar with C. :P I'll remove it. > > > -Crystal >
diff --git a/src/pi_tests/pip_stress.8 b/src/pi_tests/pip_stress.8 index 0d06dd2..f55e2d8 100644 --- a/src/pi_tests/pip_stress.8 +++ b/src/pi_tests/pip_stress.8 @@ -5,7 +5,8 @@ .B pip_stress \- Priority Inheritance with processes .SH SYNOPSIS .B pip_stress - +.RB [ \-u|\-\-usleep +.IR TIME ] .SH DESCRIPTION This program demonstrates the technique of using priority inheritance (PI) mutexes with processes instead of threads. @@ -41,6 +42,9 @@ merely increase the time that the low priority process sleeps while holding the lock. (usleep); Also note that you have to run as a user with permission to change scheduling priorities. +.SH OPTIONS +.IP "\-u TIME,\-\-usleep=TIME" +Specify the sleep time of the low priority process. Defaults to 500(us). .BR .SH AUTHOR pip_stress was written by John Kacur <jkacur at redhat.com> diff --git a/src/pi_tests/pip_stress.c b/src/pi_tests/pip_stress.c index fb0391b..782e5db 100644 --- a/src/pi_tests/pip_stress.c +++ b/src/pi_tests/pip_stress.c @@ -72,7 +72,9 @@ static void usage(int error) printf("pip_stress V %1.2f\n", VERSION); printf("Usage:\n" "pip_stress <options>\n"\ - "-h --help Show this help menu.\n" + "-h --help Show this help menu.\n"\ + "-u TIME --usleep=TIME Specify the sleep time of the low priority process.\n"\ + " Defaults to 500(us).\n" ); exit(error); } @@ -88,16 +90,20 @@ int main(int argc, char *argv[]) for (;;) { struct option long_options[] = { { "help", no_argument, NULL, 'h' }, + { "usleep", required_argument, NULL, 'u' }, { NULL, 0, NULL, 0 }, }; - int c = getopt_long(argc, argv, "s:h", long_options, NULL); + int c = getopt_long(argc, argv, "hu:", long_options, NULL); if (c == -1) break; switch (c) { case 'h': usage(0); break; + case 'u': + usleep_val = (useconds_t)strtoul(optarg, NULL, 10); + break; default: usage(1); break;
Different hardwares have different threasholds for usleep_val to reliably trigger an prio inversion, add option --usleep to allow specifying it at runtime, to facilitate testing of prio inheritance on different platforms. Signed-off-by: Shizhao Chen <shichen@redhat.com> --- src/pi_tests/pip_stress.8 | 6 +++++- src/pi_tests/pip_stress.c | 10 ++++++++-- 2 files changed, 13 insertions(+), 3 deletions(-)