X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libringbuffer%2Fshm.c;h=10b3bcef110a979ce2169ccf10417e470e122ba9;hb=ab12eb57cf3fdd2c25df16a3d1e770a2642b93e8;hp=135a2007b0e780221a0aa3cddeffe528a6e54733;hpb=4b68c31f1859175d2bd4e1b42f1b7d301e84760f;p=lttng-ust.git

diff --git a/libringbuffer/shm.c b/libringbuffer/shm.c
index 135a2007..10b3bcef 100644
--- a/libringbuffer/shm.c
+++ b/libringbuffer/shm.c
@@ -19,6 +19,7 @@
  */
 
 #define _LGPL_SOURCE
+#include <config.h>
 #include "shm.h"
 #include <unistd.h>
 #include <fcntl.h>
@@ -32,7 +33,11 @@
 #include <dirent.h>
 #include <lttng/align.h>
 #include <limits.h>
+#include <stdbool.h>
+#ifdef HAVE_LIBNUMA
 #include <numa.h>
+#include <numaif.h>
+#endif
 #include <helper.h>
 #include <ust-fd.h>
 
@@ -241,23 +246,47 @@ alloc_error:
 	return NULL;
 }
 
+/*
+ * libnuma prints errors on the console even for numa_available().
+ * Work-around this limitation by using get_mempolicy() directly to
+ * check whether the kernel supports mempolicy.
+ */
+#ifdef HAVE_LIBNUMA
+static bool lttng_is_numa_available(void)
+{
+	int ret;
+
+	ret = get_mempolicy(NULL, NULL, 0, NULL, 0);
+	if (ret && errno == ENOSYS) {
+		return false;
+	}
+	return numa_available() > 0;
+}
+#endif
+
 struct shm_object *shm_object_table_alloc(struct shm_object_table *table,
 			size_t memory_map_size,
 			enum shm_object_type type,
 			int stream_fd,
 			int cpu)
 {
-	int oldnode, node;
 	struct shm_object *shm_object;
-
-	oldnode = numa_preferred();
-	if (cpu >= 0) {
-		node = numa_node_of_cpu(cpu);
-		if (node >= 0)
-			numa_set_preferred(node);
+#ifdef HAVE_LIBNUMA
+	int oldnode = 0, node;
+	bool numa_avail;
+
+	numa_avail = lttng_is_numa_available();
+	if (numa_avail) {
+		oldnode = numa_preferred();
+		if (cpu >= 0) {
+			node = numa_node_of_cpu(cpu);
+			if (node >= 0)
+				numa_set_preferred(node);
+		}
+		if (cpu < 0 || node < 0)
+			numa_set_localalloc();
 	}
-	if (cpu < 0 || node < 0)
-		numa_set_localalloc();
+#endif /* HAVE_LIBNUMA */
 	switch (type) {
 	case SHM_OBJECT_SHM:
 		shm_object = _shm_object_table_alloc_shm(table, memory_map_size,
@@ -269,7 +298,10 @@ struct shm_object *shm_object_table_alloc(struct shm_object_table *table,
 	default:
 		assert(0);
 	}
-	numa_set_preferred(oldnode);
+#ifdef HAVE_LIBNUMA
+	if (numa_avail)
+		numa_set_preferred(oldnode);
+#endif /* HAVE_LIBNUMA */
 	return shm_object;
 }