| Message ID | 20210709155414.610308-1-nsaenzju@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/2] rt-utils: Add option to avoid stopping tracing in tracemark() | expand |
On Fri, Jul 09, 2021 at 05:54:14PM +0200, Nicolas Saenz Julienne wrote: > After a long tracing session it's sometimes hard to find the moment > oslat started. So leave a message in the trace buffer just before the > main thread starts. > > Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> > --- > src/oslat/oslat.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/src/oslat/oslat.c b/src/oslat/oslat.c > index d35be57..20bf02b 100644 > --- a/src/oslat/oslat.c > +++ b/src/oslat/oslat.c > @@ -400,6 +400,10 @@ static void *thread_main(void *arg) > while (g.n_threads_running != g.n_threads) > relax(); > > + if (!g.preheat) > + tracemark(false, "%s: Starting thread on CPU %d.\n", > + g.app_name, t->core_i); > + > frc(&t->frc_start); > doit(t); > frc(&t->frc_stop); > -- > 2.31.1 > Not sure how it would help.. but no objection either. :) Acked-by: Peter Xu <peterx@redhat.com>
Hi Peter, On Fri, 2021-07-09 at 14:39 -0400, Peter Xu wrote: > On Fri, Jul 09, 2021 at 05:54:14PM +0200, Nicolas Saenz Julienne wrote: > > After a long tracing session it's sometimes hard to find the moment > > oslat started. So leave a message in the trace buffer just before the > > main thread starts. > > > > Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> > > --- > > src/oslat/oslat.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/src/oslat/oslat.c b/src/oslat/oslat.c > > index d35be57..20bf02b 100644 > > --- a/src/oslat/oslat.c > > +++ b/src/oslat/oslat.c > > @@ -400,6 +400,10 @@ static void *thread_main(void *arg) > > while (g.n_threads_running != g.n_threads) > > relax(); > > > > + if (!g.preheat) > > + tracemark(false, "%s: Starting thread on CPU %d.\n", > > + g.app_name, t->core_i); > > + > > frc(&t->frc_start); > > doit(t); > > frc(&t->frc_stop); > > -- > > 2.31.1 > > > > Not sure how it would help.. but no objection either. :) For example, I tend to enable all trace points on Isolated CPUs. It's manageable, since once oslat runs you shouldn't be getting much action. But you get 10s/100s MBs of noise generated while oslat is being initialized. This makes finding the beginning of the test very annoying and time consuming. > Acked-by: Peter Xu <peterx@redhat.com> Thanks!
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c index a08c91d..1f3c5a2 100644 --- a/src/cyclictest/cyclictest.c +++ b/src/cyclictest/cyclictest.c @@ -12,6 +12,7 @@ #include <stdlib.h> #include <stdint.h> #include <stdarg.h> +#include <stdbool.h> #include <unistd.h> #include <fcntl.h> #include <getopt.h> @@ -722,7 +723,7 @@ static void *timerthread(void *param) pthread_mutex_lock(&break_thread_id_lock); if (break_thread_id == 0) { break_thread_id = stat->tid; - tracemark("hit latency threshold (%llu > %d)", + tracemark(true, "hit latency threshold (%llu > %d)", (unsigned long long) diff, tracelimit); break_thread_value = diff; } diff --git a/src/include/rt-utils.h b/src/include/rt-utils.h index f6b3fed..88d285b 100644 --- a/src/include/rt-utils.h +++ b/src/include/rt-utils.h @@ -31,7 +31,7 @@ int parse_time_string(char *val); int parse_mem_string(char *str, uint64_t *val); void enable_trace_mark(void); -void tracemark(char *fmt, ...) __attribute__((format(printf, 1, 2))); +void tracemark(bool stop, char *fmt, ...) __attribute__((format(printf, 2, 3))); void disable_trace_mark(void); #define MSEC_PER_SEC 1000 diff --git a/src/lib/rt-utils.c b/src/lib/rt-utils.c index 6c0235d..d8d1325 100644 --- a/src/lib/rt-utils.c +++ b/src/lib/rt-utils.c @@ -23,6 +23,7 @@ #include <sys/utsname.h> #include <time.h> #include <sys/time.h> +#include <stdbool.h> #include "rt-utils.h" #include "rt-sched.h" @@ -458,7 +459,7 @@ static void debugfs_prepare(void) "debug fs not mounted"); } -void tracemark(char *fmt, ...) +void tracemark(bool stop, char *fmt, ...) { va_list ap; int len; @@ -476,7 +477,8 @@ void tracemark(char *fmt, ...) write(tracemark_fd, tracebuf, len); /* now stop any trace */ - write(trace_fd, "0\n", 2); + if (stop) + write(trace_fd, "0\n", 2); } void enable_trace_mark(void) diff --git a/src/oslat/oslat.c b/src/oslat/oslat.c index 6ff5ba8..d35be57 100644 --- a/src/oslat/oslat.c +++ b/src/oslat/oslat.c @@ -304,7 +304,7 @@ static void insert_bucket(struct thread *t, stamp_t value) if (!g.preheat && g.trace_threshold && us >= g.trace_threshold) { char *line = "%s: Trace threshold (%d us) triggered with %u us!\n" "Stopping the test.\n"; - tracemark(line, g.app_name, g.trace_threshold, us); + tracemark(true, line, g.app_name, g.trace_threshold, us); err_quit(line, g.app_name, g.trace_threshold, us); }
Not all users of tracemark() might want to stop tracing after printing a mark. For example, if leaving a mark during a test. So add an extra argument to tracemark() which avoid the stop. Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> --- src/cyclictest/cyclictest.c | 3 ++- src/include/rt-utils.h | 2 +- src/lib/rt-utils.c | 6 ++++-- src/oslat/oslat.c | 2 +- 4 files changed, 8 insertions(+), 5 deletions(-)