virnuma: Check for numa_bitmask_isbitset presence

On some systems, libnuma can be present but it's so ancient that
it misses some symbols that virNumaGetDistances() needs. To be
more precise: numa_bitmask_isbitset() and numa_nodes_ptr are the
symbols in question. Fortunately, they were both introduced in
the same release so it's sufficient for us to check for only one
of them. And the winner is numa_bitmask_isbitset().

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/m4/virt-numactl.m4 b/m4/virt-numactl.m4
index 1dcb029a48ed9497a165b1629c901460b2bc8071..fa66d246c1db3e92c22c00d96b9fa8f80c31ac8f 100644 (file)
--- a/m4/virt-numactl.m4
+++ b/m4/virt-numactl.m4
@@ -19,6 +19,10 @@ dnl
 
 AC_DEFUN([LIBVIRT_CHECK_NUMACTL],[
   LIBVIRT_CHECK_LIB([NUMACTL], [numa], [numa_available], [numa.h])
+  AC_CHECK_LIB([numa], [numa_bitmask_isbitset], [have_numa_bitmask_isbitset=yes])
+  if test "$have_numa_bitmask_isbitset" = "yes"; then
+    AC_DEFINE_UNQUOTED([HAVE_NUMA_BITMASK_ISBITSET], 1, [whether numa_bitmask_isbitset is available])
+  fi
 ])
 
 AC_DEFUN([LIBVIRT_RESULT_NUMACTL],[

diff --git a/src/util/virnuma.c b/src/util/virnuma.c
index 042844b0f3ee0fdfc225f0fbdc2bdc580d672eac..1676208b2b761d6ca6e48b3176dc243e7c2f9879 100644 (file)
--- a/src/util/virnuma.c
+++ b/src/util/virnuma.c
@@ -216,61 +216,6 @@ virNumaGetMaxNode(void)
 }
 
 
-/**
- * virNumaGetDistances:
- * @node: identifier of the requested NUMA node
- * @distances: array of distances to sibling nodes
- * @ndistances: size of @distances
- *
- * Get array of distances to sibling nodes from @node. If a
- * distances[x] equals to zero, the node x is not enabled or
- * doesn't exist. As a special case, if @node itself refers to
- * disabled or nonexistent NUMA node, then @distances and
- * @ndistances are set to NULL and zero respectively.
- *
- * The distances are a bit of magic. For a local node the value
- * is 10, for remote it's typically 20 meaning that time penalty
- * for accessing a remote node is two time bigger than when
- * accessing a local node.
- *
- * Returns 0 on success, -1 otherwise.
- */
-int
-virNumaGetDistances(int node,
-                    int **distances,
-                    int *ndistances)
-{
-    int ret = -1;
-    int max_node;
-    size_t i;
-
-    if (!numa_bitmask_isbitset(numa_nodes_ptr, node)) {
-        VIR_DEBUG("Node %d does not exist", node);
-        *distances = NULL;
-        *ndistances = 0;
-        return 0;
-    }
-
-    if ((max_node = virNumaGetMaxNode()) < 0)
-        goto cleanup;
-
-    if (VIR_ALLOC_N(*distances, max_node) < 0)
-        goto cleanup;
-
-    *ndistances = max_node + 1;
-
-    for (i = 0; i<= max_node; i++) {
-        if (!numa_bitmask_isbitset(numa_nodes_ptr, i))
-            continue;
-
-        (*distances)[i] = numa_distance(node, i);
-    }
-
-    ret = 0;
- cleanup:
-    return ret;
-}
-
 /**
  * virNumaGetNodeMemory:
  * @node: identifier of the requested NUMA node
@@ -443,17 +388,6 @@ virNumaGetNodeCPUs(int node ATTRIBUTE_UNUSED,
                    _("NUMA isn't available on this host"));
     return -1;
 }
-
-int
-virNumaGetDistances(int node ATTRIBUTE_UNUSED,
-                    int **distances,
-                    int *ndistances)
-{
-    *distances = NULL;
-    *ndistances = 0;
-    VIR_DEBUG("NUMA isn't available on this host");
-    return 0;
-}
 #endif
 
 
@@ -469,3 +403,72 @@ virNumaGetMaxCPUs(void)
 {
     return NUMA_MAX_N_CPUS;
 }
+
+
+#ifdef HAVE_NUMA_BITMASK_ISBITSET
+/**
+ * virNumaGetDistances:
+ * @node: identifier of the requested NUMA node
+ * @distances: array of distances to sibling nodes
+ * @ndistances: size of @distances
+ *
+ * Get array of distances to sibling nodes from @node. If a
+ * distances[x] equals to zero, the node x is not enabled or
+ * doesn't exist. As a special case, if @node itself refers to
+ * disabled or nonexistent NUMA node, then @distances and
+ * @ndistances are set to NULL and zero respectively.
+ *
+ * The distances are a bit of magic. For a local node the value
+ * is 10, for remote it's typically 20 meaning that time penalty
+ * for accessing a remote node is two time bigger than when
+ * accessing a local node.
+ *
+ * Returns 0 on success, -1 otherwise.
+ */
+int
+virNumaGetDistances(int node,
+                    int **distances,
+                    int *ndistances)
+{
+    int ret = -1;
+    int max_node;
+    size_t i;
+
+    if (!numa_bitmask_isbitset(numa_nodes_ptr, node)) {
+        VIR_DEBUG("Node %d does not exist", node);
+        *distances = NULL;
+        *ndistances = 0;
+        return 0;
+    }
+
+    if ((max_node = virNumaGetMaxNode()) < 0)
+        goto cleanup;
+
+    if (VIR_ALLOC_N(*distances, max_node) < 0)
+        goto cleanup;
+
+    *ndistances = max_node + 1;
+
+    for (i = 0; i<= max_node; i++) {
+        if (!numa_bitmask_isbitset(numa_nodes_ptr, i))
+            continue;
+
+        (*distances)[i] = numa_distance(node, i);
+    }
+
+    ret = 0;
+ cleanup:
+    return ret;
+}
+#else
+int
+virNumaGetDistances(int node ATTRIBUTE_UNUSED,
+                    int **distances,
+                    int *ndistances)
+{
+    *distances = NULL;
+    *ndistances = 0;
+    VIR_DEBUG("NUMA distance information isn't availble on this host");
+    return 0;
+}
+#endif