rt-tests: cyclictest: Add option to specify main pid affinity
v2 cover rt-tests: cyclictest: Add option to specify main pid affinity
Hi John,
Changes in v2:
I moved the wrapper around numa_sched_setaffinity to lib/rt-numa.c and added the pid as a parameter. I called it try_numa_sched_setaffinity since it's basically just a wrapper, that warns if an error occurs.
I'm not sure if this is what you had in mind, when you suggested moving that section to rt-numa.c
The code-style should also be consistent now.
This patch adds the option --mainaffinity to specify the affinity of the main pid.
This is mainly useful if you want to bind the main thread to a different (e.g. housekeeping ) CPU than the measurement threads.
Regards
Jonathan
Jonathan Schwender (2):
cyclictest: Move main pid setaffinity handling into a function
cyclictest: Add --mainaffinity=[CPUSET] option.
src/cyclictest/cyclictest.c | 28 +++++++++++++++++++--------- src/include/rt-numa.h | 2 ++ src/lib/rt-numa.c | 11 +++++++++++ 3 files changed, 32 insertions(+), 9 deletions(-)
Signature · 1 line
2.29.2
PATCH v2 1/2 cyclictest: Move main pid setaffinity handling into a function
Move error handling for setting the affinity of the main pid into a separate function.
This prevents duplicating the code in the next commit, where the main thread pid can be restricted to one of two bitmasks depending on the passed parameters.
After feedback from John Kacur, the function is now located in src/lib/rt-numa.c.
This allows other tests to reuse this, if they also prefer to warn if numa_sched_setaffinity fails.
--- src/cyclictest/cyclictest.c | 8 +------- src/include/rt-numa.h | 2 ++ src/lib/rt-numa.c | 11 +++++++++++ 3 files changed, 14 insertions(+), 7 deletions(-)
src/cyclictest/cyclictest.c +1 -7
@@ -1778,13 +1778,7 @@ int main(int argc, char **argv)/* Restrict the main pid to the affinity specified by the user */ if (affinity_mask) { -int res; - - errno =0 ; - res =numa_sched_setaffinity (getpid (), affinity_mask); -if (res !=0 ) -warn ("Couldn't setaffinity in main thread: %s\n" ,strerror (errno)); - +try_numa_sched_setaffinity (getpid (), affinity_mask);if (verbose)printf ("Using %u cpus.\n" ,numa_bitmask_weight (affinity_mask));
src/include/rt-numa.h +2 -0
@@ -18,4 +18,6 @@ int cpu_for_thread_ua(int thread_num, int max_cpus);int parse_cpumask (char *str,int max_cpus,struct bitmask **cpumask); +void try_numa_sched_setaffinity (__pid_t pid,struct bitmask *cpumask); +#endif
src/lib/rt-numa.c +11 -0
@@ -133,3 +133,14 @@ int parse_cpumask(char *str, int max_cpus, struct bitmask **cpumask)return 0 ; } + +void try_numa_sched_setaffinity (__pid_t pid,struct bitmask *cpumask) +{ +int res; + + errno =0 ; + res =numa_sched_setaffinity (pid, cpumask); +if (res !=0 ) +warn ("Couldn't setaffinity for thread %d: %s\n" , pid, +strerror (errno)); +}
Signature · 1 line
2.29.2
PATCH v2 2/2 cyclictest: Add --mainaffinity=[CPUSET] option.
In reply to Jonathan SchwenderThis allows the user to specify a separate cpuset for the main pid, e.g. on a housekeeping CPU.
If --mainaffinity is not specified, but --affinity is, then the current behaviour is preserved and the main pid is bound to the cpuset specified by --affinity
--- src/cyclictest/cyclictest.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)
src/cyclictest/cyclictest.c +18 -2
@@ -836,6 +836,8 @@ static void display_help(int error)" --laptop Save battery when running cyclictest\n" " This will give you poorer realtime results\n" " but will not drain your battery so quickly\n" +" --mainaffinity=[CPUSET] Run the main thread on CPU #N. This only affects\n" +" the main thread and not the measurement threads\n" "-m --mlockall lock current and future memory allocations\n" "-M --refresh_on_max delay updating the screen until a new max\n" " latency is hit. Useful for low bandwidth.\n"
@@ -891,6 +893,7 @@ static int quiet;static int interval =DEFAULT_INTERVAL ;static int distance =-1 ;static struct bitmask *affinity_mask =NULL ; +static struct bitmask *main_affinity_mask =NULL ;static int smp =0 ;static int clocksources[] = {
@@ -943,7 +946,7 @@ enum option_values {OPT_AFFINITY =1 ,OPT_BREAKTRACE ,OPT_CLOCK ,OPT_DISTANCE ,OPT_DURATION ,OPT_LATENCY ,OPT_FIFO ,OPT_HISTOGRAM ,OPT_HISTOFALL ,OPT_HISTFILE , -OPT_INTERVAL ,OPT_LOOPS ,OPT_MLOCKALL ,OPT_REFRESH , +OPT_INTERVAL ,OPT_LOOPS ,OPT_MAINAFFINITY ,OPT_MLOCKALL ,OPT_REFRESH ,OPT_NANOSLEEP ,OPT_NSECS ,OPT_OSCOPE ,OPT_PRIORITY ,OPT_QUIET ,OPT_PRIOSPREAD ,OPT_RELATIVE ,OPT_RESOLUTION , OPT_SYSTEM, OPT_SMP, OPT_THREADS, OPT_TRIGGER,
@@ -980,6 +983,7 @@ static void process_options(int argc, char *argv[], int max_cpus) {"interval", required_argument, NULL, OPT_INTERVAL }, {"laptop", no_argument, NULL, OPT_LAPTOP }, {"loops", required_argument, NULL, OPT_LOOPS }, + {"mainaffinity", required_argument, NULL, OPT_MAINAFFINITY}, {"mlockall", no_argument, NULL, OPT_MLOCKALL }, {"refresh_on_max", no_argument, NULL, OPT_REFRESH }, {"nsecs", no_argument, NULL, OPT_NSECS },
@@ -1071,6 +1075,16 @@ static void process_options(int argc, char *argv[], int max_cpus)case 'l' :case OPT_LOOPS : max_cycles =atoi (optarg);break ; +case OPT_MAINAFFINITY : +if (optarg) { +parse_cpumask (optarg, max_cpus, &main_affinity_mask); + }else if (optind < argc && + (atoi (argv[optind]) || + argv[optind][0 ] =='0' || + argv[optind][0 ] =='!' )) { +parse_cpumask (argv[optind], max_cpus, &main_affinity_mask); + } +break ;case 'm' :case OPT_MLOCKALL : lockall =1 ;break ;
@@ -1777,7 +1791,9 @@ int main(int argc, char **argv) }/* Restrict the main pid to the affinity specified by the user */ -if (affinity_mask) { +if (main_affinity_mask) { +try_numa_sched_setaffinity (getpid (), main_affinity_mask); + }else if (affinity_mask) {try_numa_sched_setaffinity (getpid (), affinity_mask);if (verbose) printf("Using %u cpus.\n",
Signature · 1 line
2.29.2