Introduce KMP_DEVICE_THREAD_LIMIT

This change drops in KMP_DEVICE_THREAD_LIMIT to replace KMP_MAX_THREADS. It's
possible there will eventually be a OMP_DEVICE_THREAD_LIMIT, and we need
something to distinguish from OMP_THREAD_LIMIT, which is currently implemented
incorrectly (the fix for that will be added soon in a separate patch).
KMP_ALL_THREADS is deprecated here, but we can keep the "all" option on
KMP_DEVICE_THREAD_LIMIT to support that functionality. KMP_DEVICE_THREAD_LIMIT
now has priority over its deprecated rival KMP_ALL_THREADS. I also cleaned up
some comments that incorrectly referred to non-existent kmp_max_threads variable
instead of kmp_max_nth.

I've left the name of where this setting eventually ends up as
__kmp_max_nth, for now.

This change does not change much in the way of functionality. It does NOT change
OMP_THREAD_LIMIT. It's just cleaning up and setting up for that.

Patch by Terry Wilmarth

Differential Revision: https://reviews.llvm.org/D35860

llvm-svn: 309168
This commit is contained in:
Jonathan Peyton 2017-07-26 20:07:58 +00:00
parent 55038cd1d3
commit 09244f39dd
2 changed files with 28 additions and 29 deletions

View File

@ -881,7 +881,7 @@ static int __kmp_reserve_threads(kmp_root_t *root, kmp_team_t *parent_team,
KMP_ASSERT(0);
}
// Respect KMP_ALL_THREADS, KMP_MAX_THREADS, OMP_THREAD_LIMIT.
// Respect KMP_ALL_THREADS, KMP_DEVICE_THREAD_LIMIT, OMP_THREAD_LIMIT.
if (__kmp_nth + new_nthreads -
(root->r.r_active ? 1 : root->r.r_hot_team->t.t_nproc) >
__kmp_max_nth) {
@ -3513,7 +3513,7 @@ static int __kmp_expand_threads(int nWish, int nNeed) {
//
// 1) The initialization thread (gtid = 0) exits. __kmp_threads[0]
// may not be resused by another thread, so we may need to increase
// __kmp_threads_capacity to __kmp_max_threads + 1.
// __kmp_threads_capacity to __kmp_max_nth + 1.
//
// 2) New foreign root(s) are encountered. We always register new foreign
// roots. This may cause a smaller # of threads to be allocated at
@ -3521,7 +3521,7 @@ static int __kmp_expand_threads(int nWish, int nNeed) {
// eventually go to sleep) and need slots in the __kmp_threads[] array.
//
// Anyway, that is the reason for moving the check to see if
// __kmp_max_threads was exceeded into __kmp_reseerve_threads()
// __kmp_max_nth was exceeded into __kmp_reserve_threads()
// instead of having it performed here. -BB
old_tp_cached = __kmp_tp_cached;
__kmp_actual_max_nth =

View File

@ -569,13 +569,15 @@ static void __kmp_stg_print_size(kmp_str_buf_t *buffer, char const *name,
// Parse and print functions.
// -----------------------------------------------------------------------------
// KMP_ALL_THREADS, KMP_MAX_THREADS, OMP_THREAD_LIMIT
static void __kmp_stg_parse_all_threads(char const *name, char const *value,
void *data) {
// KMP_ALL_THREADS, KMP_DEVICE_THREAD_LIMIT, OMP_THREAD_LIMIT
static void __kmp_stg_parse_device_thread_limit(char const *name,
char const *value, void *data) {
kmp_setting_t **rivals = (kmp_setting_t **)data;
int rc;
if (strcmp(name, "KMP_ALL_THREADS") == 0) {
KMP_INFORM(EnvVarDeprecated, name, "KMP_DEVICE_THREAD_LIMIT");
}
rc = __kmp_stg_check_rivals(name, value, rivals);
if (rc) {
return;
@ -589,12 +591,12 @@ static void __kmp_stg_parse_all_threads(char const *name, char const *value,
}
K_DIAG(1, ("__kmp_max_nth == %d\n", __kmp_max_nth));
} // __kmp_stg_parse_all_threads
} // __kmp_stg_parse_device_thread_limit
static void __kmp_stg_print_all_threads(kmp_str_buf_t *buffer, char const *name,
void *data) {
static void __kmp_stg_print_device_thread_limit(kmp_str_buf_t *buffer,
char const *name, void *data) {
__kmp_stg_print_int(buffer, name, __kmp_max_nth);
} // __kmp_stg_print_all_threads
} // __kmp_stg_print_device_thread_limit
// -----------------------------------------------------------------------------
// KMP_BLOCKTIME
@ -4336,16 +4338,15 @@ static void __kmp_stg_print_omp_cancellation(kmp_str_buf_t *buffer,
static kmp_setting_t __kmp_stg_table[] = {
{"KMP_ALL_THREADS", __kmp_stg_parse_all_threads,
__kmp_stg_print_all_threads, NULL, 0, 0},
{"KMP_ALL_THREADS", __kmp_stg_parse_device_thread_limit, NULL, NULL, 0, 0},
{"KMP_BLOCKTIME", __kmp_stg_parse_blocktime, __kmp_stg_print_blocktime,
NULL, 0, 0},
{"KMP_DUPLICATE_LIB_OK", __kmp_stg_parse_duplicate_lib_ok,
__kmp_stg_print_duplicate_lib_ok, NULL, 0, 0},
{"KMP_LIBRARY", __kmp_stg_parse_wait_policy, __kmp_stg_print_wait_policy,
NULL, 0, 0},
{"KMP_MAX_THREADS", __kmp_stg_parse_all_threads, NULL, NULL, 0,
0}, // For backward compatibility
{"KMP_DEVICE_THREAD_LIMIT", __kmp_stg_parse_device_thread_limit,
__kmp_stg_print_device_thread_limit, NULL, 0, 0},
#if KMP_USE_MONITOR
{"KMP_MONITOR_STACKSIZE", __kmp_stg_parse_monitor_stacksize,
__kmp_stg_print_monitor_stacksize, NULL, 0, 0},
@ -4385,8 +4386,8 @@ static kmp_setting_t __kmp_stg_table[] = {
{"KMP_TASKLOOP_MIN_TASKS", __kmp_stg_parse_taskloop_min_tasks,
__kmp_stg_print_taskloop_min_tasks, NULL, 0, 0},
#endif
{"OMP_THREAD_LIMIT", __kmp_stg_parse_all_threads,
__kmp_stg_print_all_threads, NULL, 0, 0},
{"OMP_THREAD_LIMIT", __kmp_stg_parse_device_thread_limit,
__kmp_stg_print_device_thread_limit, NULL, 0, 0},
{"OMP_WAIT_POLICY", __kmp_stg_parse_wait_policy,
__kmp_stg_print_wait_policy, NULL, 0, 0},
{"KMP_DISP_NUM_BUFFERS", __kmp_stg_parse_disp_buffers,
@ -4686,11 +4687,12 @@ static void __kmp_stg_init(void) {
}; // if
}
{ // Initialize KMP_ALL_THREADS, KMP_MAX_THREADS, and OMP_THREAD_LIMIT data.
{ // Initialize KMP_DEVICE_THREAD_LIMIT, KMP_ALL_THREADS, and
// OMP_THREAD_LIMIT data.
kmp_setting_t *kmp_device_thread_limit =
__kmp_stg_find("KMP_DEVICE_THREAD_LIMIT"); // 1st priority.
kmp_setting_t *kmp_all_threads =
__kmp_stg_find("KMP_ALL_THREADS"); // 1st priority.
kmp_setting_t *kmp_max_threads =
__kmp_stg_find("KMP_MAX_THREADS"); // 2nd priority.
__kmp_stg_find("KMP_ALL_THREADS"); // 2nd priority.
kmp_setting_t *omp_thread_limit =
__kmp_stg_find("OMP_THREAD_LIMIT"); // 3rd priority.
@ -4698,17 +4700,14 @@ static void __kmp_stg_init(void) {
static kmp_setting_t *volatile rivals[4];
int i = 0;
rivals[i++] = kmp_device_thread_limit;
rivals[i++] = kmp_all_threads;
rivals[i++] = kmp_max_threads;
if (omp_thread_limit != NULL) {
rivals[i++] = omp_thread_limit;
}; // if
rivals[i++] = omp_thread_limit;
rivals[i++] = NULL;
kmp_device_thread_limit->data = CCAST(kmp_setting_t **, rivals);
kmp_all_threads->data = CCAST(kmp_setting_t **, rivals);
kmp_max_threads->data = CCAST(kmp_setting_t **, rivals);
if (omp_thread_limit != NULL) {
omp_thread_limit->data = CCAST(kmp_setting_t **, rivals);
}; // if
omp_thread_limit->data = CCAST(kmp_setting_t **, rivals);
}
#if KMP_AFFINITY_SUPPORTED