Changeset: e901a749aa57 for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=e901a749aa57
Modified Files:
gdk/gdk_system.c
Branch: default
Log Message:
If we can't easily determine the number of cores, just use 1.
Easily means using a system call. All our testing systems use one of
the forms that remain.
diffs (62 lines):
diff --git a/gdk/gdk_system.c b/gdk/gdk_system.c
--- a/gdk/gdk_system.c
+++ b/gdk/gdk_system.c
@@ -714,49 +714,6 @@ MT_getpid(void)
#endif
}
-#define SMP_TOLERANCE 0.40
-#define SMP_ROUNDS 1024*1024*128
-
-static void
-smp_thread(void *data)
-{
- unsigned int s = 1, r;
-
- (void) data;
- for (r = 0; r < SMP_ROUNDS; r++)
- s = s * r + r;
- (void) s;
-}
-
-static int
-MT_check_nr_cores_(void)
-{
- int i, curr = 1, cores = 1;
- double lasttime = 0, thistime;
- while (1) {
- lng t0, t1;
- MT_Id *threads = malloc(sizeof(MT_Id) * curr);
-
- if (threads == NULL)
- break;
-
- t0 = GDKusec();
- for (i = 0; i < curr; i++)
- MT_create_thread(threads + i, smp_thread, NULL,
MT_THR_JOINABLE);
- for (i = 0; i < curr; i++)
- MT_join_thread(threads[i]);
- t1 = GDKusec();
- free(threads);
- thistime = (double) (t1 - t0) / 1000000;
- if (lasttime > 0 && thistime / lasttime > 1 + SMP_TOLERANCE)
- break;
- lasttime = thistime;
- cores = curr;
- curr *= 2; /* only check for powers of 2 */
- }
- return cores;
-}
-
int
MT_check_nr_cores(void)
{
@@ -786,7 +743,7 @@ MT_check_nr_cores(void)
* http://ndevilla.free.fr/threads/ */
if (ncpus <= 0)
- ncpus = MT_check_nr_cores_();
+ ncpus = 1;
#if SIZEOF_SIZE_T == SIZEOF_INT
/* On 32-bits systems with large amounts of cpus/cores, we quickly
* run out of space due to the amount of threads in use. Since it
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