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| author | Ivan Maidanski <ivmai@mail.ru> | 2023-04-25 09:42:58 +0300 |
|---|---|---|
| committer | Ivan Maidanski <ivmai@mail.ru> | 2023-04-25 11:13:42 +0300 |
| commit | 11dc704f55251f5c53b3dc6f79bec148659bdd88 (patch) | |
| tree | c5940305692f9d544e8e67065fb1130bd9aa5154 | |
| parent | 4bdf9b9c327673b71344a63e368d8b2386bae6af (diff) | |
| download | bdwgc-11dc704f55251f5c53b3dc6f79bec148659bdd88.tar.gz | |
Allow to randomly choose a CPU core if AO ops are emulated with locks
This is needed for test purpose to have all test processes to run on
different CPU cores (even if each process occupies just one core).
* pthread_support.c [!GC_WIN32_THREADS && BASE_ATOMIC_OPS_EMULATED
&& SIGNAL_BASED_STOP_WORLD && RANDOM_ONE_CPU_CORE] (GC_thr_init):
Define and set cpu_highest_set variable; update cpu_lowest_set based
getpid() and cpu_highest_set values (so that to have cpu_lowest_set
randomly set between lowest and highest set bits in the mask); add
comment.
| -rw-r--r-- | pthread_support.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/pthread_support.c b/pthread_support.c index 6430f60b..c1232cef 100644 --- a/pthread_support.c +++ b/pthread_support.c @@ -1648,6 +1648,9 @@ GC_INNER void GC_thr_init(void) cpu_set_t mask; int cpu_set_cnt = 0; int cpu_lowest_set = 0; +# ifdef RANDOM_ONE_CPU_CORE + int cpu_highest_set = 0; +# endif int i = GC_nprocs > 1 ? GC_nprocs : 2; /* check at least 2 cores */ if (sched_getaffinity(0 /* current process */, @@ -1655,12 +1658,22 @@ GC_INNER void GC_thr_init(void) ABORT_ARG1("sched_getaffinity failed", ": errno= %d", errno); while (i-- > 0) if (CPU_ISSET(i, &mask)) { +# ifdef RANDOM_ONE_CPU_CORE + if (i + 1 != cpu_lowest_set) cpu_highest_set = i; +# endif cpu_lowest_set = i; cpu_set_cnt++; } if (0 == cpu_set_cnt) ABORT("sched_getaffinity returned empty mask"); if (cpu_set_cnt > 1) { +# ifdef RANDOM_ONE_CPU_CORE + if (cpu_lowest_set < cpu_highest_set) { + /* Pseudo-randomly adjust the bit to set among valid ones. */ + cpu_lowest_set += (unsigned)getpid() % + (cpu_highest_set - cpu_lowest_set + 1); + } +# endif CPU_ZERO(&mask); CPU_SET(cpu_lowest_set, &mask); /* select just one CPU */ if (sched_setaffinity(0, sizeof(mask), &mask) == -1) |