From: Pierre-Marc Fournier <pierre-marc.fournier@polymtl.ca>
Date: Tue, 2 Feb 2010 02:43:03 +0000 (-0500)
Subject: _SC_NPROCESSORS_ONLN -> _SC_NPROCESSORS_CONF
X-Git-Tag: v1.9.1~759
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=a0243ab12a9cdab191c624ef23e035d97f08d60e;p=lttng-ust.git

_SC_NPROCESSORS_ONLN -> _SC_NPROCESSORS_CONF
---

diff --git a/libust/buffers.c b/libust/buffers.c
index 13660a89..7d2dd473 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;
 	}