| Message ID | d66dd64f84d9e34ed19f5a0f6643ad4cdc94b4dc.1543844172.git.jstancek@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v3] fzsync: limit sampling time | expand |
Hello, Jan Stancek <jstancek@redhat.com> writes: > Fixes: #429 > > Sampling can take considerably longer time on single CPU > and very slow systems. This patch limits sampling time to > 1/2 of fuzzing runtime. If we don't have enough samples by > that time, stop sampling and use stats we gathered so far. > > Signed-off-by: Jan Stancek <jstancek@redhat.com> > --- > include/tst_fuzzy_sync.h | 21 ++++++++++++++------- > 1 file changed, 14 insertions(+), 7 deletions(-) > > Changes in v3: > - base sampling time directly on exec time > > diff --git a/include/tst_fuzzy_sync.h b/include/tst_fuzzy_sync.h > index 03f69b78bc82..18b9d265bbb4 100644 > --- a/include/tst_fuzzy_sync.h > +++ b/include/tst_fuzzy_sync.h > @@ -70,6 +70,9 @@ > #ifndef TST_FUZZY_SYNC_H__ > #define TST_FUZZY_SYNC_H__ > > +/* how much of exec time is sampling allowed to take */ > +#define SAMPLING_SLICE 0.5f > + > /** Some statistics for a variable */ > struct tst_fzsync_stat { > float avg; > @@ -582,17 +585,21 @@ static inline void tst_fzsync_wait_b(struct tst_fzsync_pair *pair) > static inline int tst_fzsync_run_a(struct tst_fzsync_pair *pair) > { > int exit = 0; > + float rem_p = 1 - tst_timeout_remaining() / pair->exec_time_start; > + > + /* Limit amount of time spent on sampling */ I think this comment is redundant as you have documented the variable and there is also the tst_res message. You could maybe add more info in the message though. Like "Stopped sampling at %d (out of %d) samples because sampling time reached 50% of the total time limit". > + if ((pair->exec_time_p * SAMPLING_SLICE < rem_p) > + && (pair->sampling > 0)) { > + tst_res(TINFO, "stopping sampling at %d samples", > + pair->exec_loop); > + pair->sampling = 0; > + tst_fzsync_pair_info(pair); > + } > > - if (pair->exec_time_p > - < 1 - tst_timeout_remaining() / pair->exec_time_start) { > + if (pair->exec_time_p < rem_p) { > tst_res(TINFO, > "Exceeded execution time, requesting exit"); > exit = 1; > - > - if (pair->sampling > 0) { > - tst_res(TWARN, > - "Still sampling, consider increasing LTP_TIMEOUT_MUL"); > - } > } > > if (++pair->exec_loop > pair->exec_loops) { -- Thank you, Richard.
diff --git a/include/tst_fuzzy_sync.h b/include/tst_fuzzy_sync.h index 03f69b78bc82..18b9d265bbb4 100644 --- a/include/tst_fuzzy_sync.h +++ b/include/tst_fuzzy_sync.h @@ -70,6 +70,9 @@ #ifndef TST_FUZZY_SYNC_H__ #define TST_FUZZY_SYNC_H__ +/* how much of exec time is sampling allowed to take */ +#define SAMPLING_SLICE 0.5f + /** Some statistics for a variable */ struct tst_fzsync_stat { float avg; @@ -582,17 +585,21 @@ static inline void tst_fzsync_wait_b(struct tst_fzsync_pair *pair) static inline int tst_fzsync_run_a(struct tst_fzsync_pair *pair) { int exit = 0; + float rem_p = 1 - tst_timeout_remaining() / pair->exec_time_start; + + /* Limit amount of time spent on sampling */ + if ((pair->exec_time_p * SAMPLING_SLICE < rem_p) + && (pair->sampling > 0)) { + tst_res(TINFO, "stopping sampling at %d samples", + pair->exec_loop); + pair->sampling = 0; + tst_fzsync_pair_info(pair); + } - if (pair->exec_time_p - < 1 - tst_timeout_remaining() / pair->exec_time_start) { + if (pair->exec_time_p < rem_p) { tst_res(TINFO, "Exceeded execution time, requesting exit"); exit = 1; - - if (pair->sampling > 0) { - tst_res(TWARN, - "Still sampling, consider increasing LTP_TIMEOUT_MUL"); - } } if (++pair->exec_loop > pair->exec_loops) {
Fixes: #429 Sampling can take considerably longer time on single CPU and very slow systems. This patch limits sampling time to 1/2 of fuzzing runtime. If we don't have enough samples by that time, stop sampling and use stats we gathered so far. Signed-off-by: Jan Stancek <jstancek@redhat.com> --- include/tst_fuzzy_sync.h | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) Changes in v3: - base sampling time directly on exec time