[libvirt] [PATCH 1/2] node_memory: Do not fail if there is parameter unsupported

Osier Yang jyang at redhat.com
Thu Nov 22 03:14:39 UTC 2012


It makes no sense to fail the whole command if there is parameter
unsupported by the kernel. This patch fixes it by ignoring the
unsupported parameter for getMemoryParameters, and ignoring the
unsupported parameter for setMemoryParameters too if there are
more than one parameters to set, otherwise error out.
---
 src/libvirt.c  |   12 +++--
 src/nodeinfo.c |  119 ++++++++++++++++++++++++++++++++++----------------------
 2 files changed, 79 insertions(+), 52 deletions(-)

diff --git a/src/libvirt.c b/src/libvirt.c
index 4af6089..93ec068 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -6746,10 +6746,10 @@ error:
  * @nparams: pointer to number of memory parameters; input and output
  * @flags: extra flags; not used yet, so callers should always pass 0
  *
- * Get all node memory parameters.  On input, @nparams gives the size
- * of the @params array; on output, @nparams gives how many slots were
- * filled with parameter information, which might be less but will
- * not exceed the input value.
+ * Get all node memory parameters (parameter unsupported by OS will be
+ * ignored).  On input, @nparams gives the size of the @params array;
+ * on output, @nparams gives how many slots were filled with parameter
+ * information, which might be less but will not exceed the input value.
  *
  * As a special case, calling with @params as NULL and @nparams as 0 on
  * input will cause @nparams on output to contain the number of parameters
@@ -6811,7 +6811,9 @@ error:
  *           value nparams of virDomainGetSchedulerType)
  * @flags: extra flags; not used yet, so callers should always pass 0
  *
- * Change all or a subset of the node memory tunables.
+ * Change all or a subset of the node memory tunables. Tunable
+ * unsupported by OS wll be ignored if @nparams is not 1, otherwise
+ * the function fails.
  *
  * Note that it's not recommended to use this function while the
  * outside tuning program is running (such as ksmtuned under Linux),
diff --git a/src/nodeinfo.c b/src/nodeinfo.c
index 75d6524..718a3a4 100644
--- a/src/nodeinfo.c
+++ b/src/nodeinfo.c
@@ -1058,21 +1058,13 @@ nodeGetCPUBitmap(int *max_id ATTRIBUTE_UNUSED)
 
 #ifdef __linux__
 static int
-nodeSetMemoryParameterValue(const char *field,
+nodeSetMemoryParameterValue(const char *path,
                             virTypedParameterPtr param)
 {
-    char *path = NULL;
     char *strval = NULL;
     int ret = -1;
     int rc = -1;
 
-    if (virAsprintf(&path, "%s/%s",
-                    SYSFS_MEMORY_SHARED_PATH, field) < 0) {
-        virReportOOMError();
-        ret = -2;
-        goto cleanup;
-    }
-
     if (virAsprintf(&strval, "%u", param->value.ui) == -1) {
         virReportOOMError();
         ret = -2;
@@ -1080,13 +1072,12 @@ nodeSetMemoryParameterValue(const char *field,
     }
 
     if ((rc = virFileWriteStr(path, strval, 0)) < 0) {
-        virReportSystemError(-rc, _("failed to set %s"), field);
+        virReportSystemError(-rc, _("failed to set %s"), param->field);
         goto cleanup;
     }
 
     ret = 0;
 cleanup:
-    VIR_FREE(path);
     VIR_FREE(strval);
     return ret;
 }
@@ -1101,7 +1092,9 @@ nodeSetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
     virCheckFlags(0, -1);
 
 #ifdef __linux__
-    int ret = 0;
+    char *path = NULL;
+    int ret = -1;
+    int rc;
     int i;
 
     if (virTypedParameterArrayValidate(params, nparams,
@@ -1117,30 +1110,40 @@ nodeSetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
     for (i = 0; i < nparams; i++) {
         virTypedParameterPtr param = &params[i];
 
-        if (STREQ(param->field,
-                  VIR_NODE_MEMORY_SHARED_PAGES_TO_SCAN)) {
-            ret = nodeSetMemoryParameterValue("pages_to_scan", param);
+        char *field = strchr(param->field, '_');
+        field++;
+        if (virAsprintf(&path, "%s/%s",
+                        SYSFS_MEMORY_SHARED_PATH, field) < 0) {
+            virReportOOMError();
+            goto cleanup;
+        }
 
-            /* Out of memory */
-            if (ret == -2)
-                return -1;
-        } else if (STREQ(param->field,
-                         VIR_NODE_MEMORY_SHARED_SLEEP_MILLISECS)) {
-            ret = nodeSetMemoryParameterValue("sleep_millisecs", param);
+        /* Ignore the unsupported the param field if there is other
+         * parameter to set, otherwise error out.
+         */
+        if (!virFileExists(path)) {
+            if (nparams == 1) {
+                virReportError(VIR_ERR_OPERATION_INVALID,
+                               _("Parameter '%s' is not supported by "
+                                 "this kernel"), param->field);
+                goto cleanup;
+            } else {
+                VIR_WARN("Parameter '%s' is not supported by this kernel",
+                         param->field);
+                continue;
+            }
+        }
 
-            /* Out of memory */
-            if (ret == -2)
-                return -1;
-        } else if (STREQ(param->field,
-                         VIR_NODE_MEMORY_SHARED_MERGE_ACROSS_NODES)) {
-            ret = nodeSetMemoryParameterValue("merge_across_nodes", param);
+        rc = nodeSetMemoryParameterValue(path, param);
 
-            /* Out of memory */
-            if (ret == -2)
-                return -1;
-        }
+        /* Out of memory */
+        if (rc == -2)
+            goto cleanup;
     }
 
+    ret = 0;
+cleanup:
+    VIR_FREE(path);
     return ret;
 #else
     virReportError(VIR_ERR_NO_SUPPORT, "%s",
@@ -1167,6 +1170,11 @@ nodeGetMemoryParameterValue(const char *field,
         goto cleanup;
     }
 
+    if (!virFileExists(path)) {
+        ret = -2;
+        goto cleanup;
+    }
+
     if (virFileReadAll(path, 1024, &buf) < 0)
         goto cleanup;
 
@@ -1217,6 +1225,7 @@ nodeGetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
     unsigned long long pages_volatile;
     unsigned long long full_scans = 0;
     int i;
+    int ret;
 
     if ((*nparams) == 0) {
         *nparams = NODE_MEMORY_PARAMETERS_NUM;
@@ -1228,8 +1237,10 @@ nodeGetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
 
         switch (i) {
         case 0:
-            if (nodeGetMemoryParameterValue("pages_to_scan",
-                                            &pages_to_scan) < 0)
+            ret = nodeGetMemoryParameterValue("pages_to_scan", &pages_to_scan);
+            if (ret == -2)
+                continue;
+            else if (ret == -1)
                 return -1;
 
             if (virTypedParameterAssign(param, VIR_NODE_MEMORY_SHARED_PAGES_TO_SCAN,
@@ -1239,8 +1250,10 @@ nodeGetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
             break;
 
         case 1:
-            if (nodeGetMemoryParameterValue("sleep_millisecs",
-                                            &sleep_millisecs) < 0)
+            ret = nodeGetMemoryParameterValue("sleep_millisecs", &sleep_millisecs);
+            if (ret == -2)
+                continue;
+            else if (ret == -1)
                 return -1;
 
             if (virTypedParameterAssign(param, VIR_NODE_MEMORY_SHARED_SLEEP_MILLISECS,
@@ -1250,8 +1263,10 @@ nodeGetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
             break;
 
         case 2:
-            if (nodeGetMemoryParameterValue("pages_shared",
-                                            &pages_shared) < 0)
+            ret = nodeGetMemoryParameterValue("pages_shared", &pages_shared);
+            if (ret == -2)
+                continue;
+            else if (ret == -1)
                 return -1;
 
             if (virTypedParameterAssign(param, VIR_NODE_MEMORY_SHARED_PAGES_SHARED,
@@ -1261,8 +1276,10 @@ nodeGetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
             break;
 
         case 3:
-            if (nodeGetMemoryParameterValue("pages_sharing",
-                                            &pages_sharing) < 0)
+            ret = nodeGetMemoryParameterValue("pages_sharing", &pages_sharing);
+            if (ret == -2)
+                continue;
+            else if (ret == -1)
                 return -1;
 
             if (virTypedParameterAssign(param, VIR_NODE_MEMORY_SHARED_PAGES_SHARING,
@@ -1272,8 +1289,10 @@ nodeGetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
             break;
 
         case 4:
-            if (nodeGetMemoryParameterValue("pages_unshared",
-                                            &pages_unshared) < 0)
+            ret = nodeGetMemoryParameterValue("pages_unshared", &pages_unshared);
+            if (ret == -2)
+                continue;
+            else if (ret == -1)
                 return -1;
 
             if (virTypedParameterAssign(param, VIR_NODE_MEMORY_SHARED_PAGES_UNSHARED,
@@ -1283,8 +1302,10 @@ nodeGetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
             break;
 
         case 5:
-            if (nodeGetMemoryParameterValue("pages_volatile",
-                                            &pages_volatile) < 0)
+            ret = nodeGetMemoryParameterValue("pages_volatile", &pages_volatile);
+            if (ret == -2)
+                continue;
+            else if (ret == -1)
                 return -1;
 
             if (virTypedParameterAssign(param, VIR_NODE_MEMORY_SHARED_PAGES_VOLATILE,
@@ -1294,8 +1315,10 @@ nodeGetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
             break;
 
         case 6:
-            if (nodeGetMemoryParameterValue("full_scans",
-                                            &full_scans) < 0)
+            ret = nodeGetMemoryParameterValue("full_scans", &full_scans);
+            if (ret == -2)
+                continue;
+            else if (ret == -1)
                 return -1;
 
             if (virTypedParameterAssign(param, VIR_NODE_MEMORY_SHARED_FULL_SCANS,
@@ -1305,8 +1328,10 @@ nodeGetMemoryParameters(virConnectPtr conn ATTRIBUTE_UNUSED,
             break;
 
         case 7:
-            if (nodeGetMemoryParameterValue("merge_across_nodes",
-                                            &merge_across_nodes) < 0)
+            ret = nodeGetMemoryParameterValue("merge_across_nodes", &merge_across_nodes);
+            if (ret == -2)
+                continue;
+            else if (ret == -1)
                 return -1;
 
             if (virTypedParameterAssign(param, VIR_NODE_MEMORY_SHARED_MERGE_ACROSS_NODES,
-- 
1.7.7.6




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