prio-wake: enable using more than 95 threads prio-wake will currently spew pthread errors on systems with more than 95 CPUS, or if an -n value > 95 is specified on the command line. To avoid this, spread threads out equally over the priorities by calculated the number of threads per priority.
Tested with all pathological numbers (i.e. mod=0 mod=1, etc) of threads. Ran 10000 times in parallel. Confirmed failure continues to exist without requeue PI (as it should) and success is seen with requeue PI (as it should be). Signed-off-by: Darren Hart <[email protected]> Acked-By: Dinakar Guniguntala <[email protected]> Acked-by: Vernon Mauery <[email protected]> Acked-by: Gowrishankar <[email protected]> --- func/prio-wake/prio-wake.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) Index: realtime/func/prio-wake/prio-wake.c =================================================================== --- realtime.orig/func/prio-wake/prio-wake.c +++ realtime/func/prio-wake/prio-wake.c @@ -54,6 +54,8 @@ #include <errno.h> #include <sys/syscall.h> #include <librttest.h> +#include <libstats.h> + volatile int running_threads = 0; static int rt_threads = 0; static int locked_broadcast = 1; @@ -164,8 +166,10 @@ void *worker_thread(void* arg) int main(int argc, char* argv[]) { - int pri_boost; + int threads_per_prio; int numcpus; + int numprios; + int prio; int i; setup(); @@ -184,19 +188,29 @@ int main(int argc, char* argv[]) printf("Calling pthread_cond_broadcast() with mutex: %s\n\n", locked_broadcast ? "LOCKED" : "UNLOCKED"); - pri_boost = 3; - beginrun = rt_gettime(); init_pi_mutex(&mutex); + /* calculate the number of threads per priority */ + /* we get num numprios -1 for the workers, leaving one for the master */ + numprios = sched_get_priority_max(SCHED_FIFO) - + sched_get_priority_min(SCHED_FIFO); + + threads_per_prio = rt_threads / numprios; + if (rt_threads % numprios) + threads_per_prio++; + /* start the worker threads */ + prio = sched_get_priority_min(SCHED_FIFO); for (i = rt_threads; i > 0; i--) { - create_fifo_thread(worker_thread, (void*)(intptr_t)i, sched_get_priority_min(SCHED_FIFO) + pri_boost++); + if ((i != rt_threads && (i % threads_per_prio) == 0)) + prio++; + create_fifo_thread(worker_thread, (void*)(intptr_t)i, prio); } /* start the master thread */ - create_fifo_thread(master_thread, (void*)(intptr_t)i, sched_get_priority_min(SCHED_FIFO) + pri_boost); + create_fifo_thread(master_thread, (void*)(intptr_t)i, ++prio); /* wait for threads to complete */ join_threads(); -- Darren Hart IBM Linux Technology Center Real-Time Linux Team ------------------------------------------------------------------------------ The Planet: dedicated and managed hosting, cloud storage, colocation Stay online with enterprise data centers and the best network in the business Choose flexible plans and management services without long-term contracts Personal 24x7 support from experience hosting pros just a phone call away. http://p.sf.net/sfu/theplanet-com _______________________________________________ Ltp-list mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ltp-list
