X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=libust%2Fbuffers.c;h=7d2dd47336ecfda237a6d6564b99f2bca38f3000;hb=a0243ab12a9cdab191c624ef23e035d97f08d60e;hp=13660a8910402ad45e163c524aa845d37025a6df;hpb=204141ee9da22a244c9095287f4f1c513784b171;p=ust.git

diff --git a/libust/buffers.c b/libust/buffers.c
index 13660a8..7d2dd47 100644
--- a/libust/buffers.c
+++ b/libust/buffers.c
@@ -45,7 +45,15 @@ static int get_n_cpus(void)
 		return n_cpus;
 	}
 
-	result = sysconf(_SC_NPROCESSORS_ONLN);
+	/* On Linux, when some processors are offline
+	 * _SC_NPROCESSORS_CONF counts the offline
+	 * processors, whereas _SC_NPROCESSORS_ONLN
+	 * does not. If we used _SC_NPROCESSORS_ONLN,
+	 * getcpu() could return a value greater than
+	 * this sysconf, in which case the arrays
+	 * indexed by processor would overflow.
+	 */
+	result = sysconf(_SC_NPROCESSORS_CONF);
 	if(result == -1) {
 		return -1;
 	}