util: Add more interfaces for resctrl monitor

Add interfaces monitor group to support operations such
as GetID, SetID, Remove, SetAlloc, etc.

Implement the internal virResctrlMonitorGetStats to fetch all
the statistical data and the virResctrlMonitorGetCacheOccupancy
in order to fetch the cache specific "llc_occupancy" value.

Signed-off-by: Wang Huaqiang <huaqiang.wang@intel.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 85633bd116c863c505c57f830cfb187ec7201144..1f8c3d04c19c5df712a21bf357d63fc0649a620f 100644 (file)
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2684,7 +2684,12 @@ virResctrlInfoNew;
 virResctrlMonitorAddPID;
 virResctrlMonitorCreate;
 virResctrlMonitorDeterminePath;
+virResctrlMonitorGetCacheOccupancy;
+virResctrlMonitorGetID;
 virResctrlMonitorNew;
+virResctrlMonitorRemove;
+virResctrlMonitorSetAlloc;
+virResctrlMonitorSetID;
 
 
 # util/virrotatingfile.h

diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c
index 90eda726f87c84706fd7dbc51e0167d1fdcfb998..f7481a10360f7980b04711db774bdcb3fdc498e7 100644 (file)
--- a/src/util/virresctrl.c
+++ b/src/util/virresctrl.c
@@ -2585,3 +2585,179 @@ virResctrlMonitorCreate(virResctrlMonitorPtr monitor,
     virResctrlUnlock(lockfd);
     return ret;
 }
+
+
+int
+virResctrlMonitorSetID(virResctrlMonitorPtr monitor,
+                       const char *id)
+
+{
+    return virResctrlSetID(&monitor->id, id);
+}
+
+
+const char *
+virResctrlMonitorGetID(virResctrlMonitorPtr monitor)
+{
+    return monitor->id;
+}
+
+
+void
+virResctrlMonitorSetAlloc(virResctrlMonitorPtr monitor,
+                          virResctrlAllocPtr alloc)
+{
+    monitor->alloc = virObjectRef(alloc);
+}
+
+
+int
+virResctrlMonitorRemove(virResctrlMonitorPtr monitor)
+{
+    int ret = 0;
+
+    if (!monitor->path)
+        return 0;
+
+    if (STREQ(monitor->path, monitor->alloc->path))
+        return 0;
+
+    VIR_DEBUG("Removing resctrl monitor path=%s", monitor->path);
+    if (rmdir(monitor->path) != 0 && errno != ENOENT) {
+        ret = -errno;
+        VIR_ERROR(_("Unable to remove %s (%d)"), monitor->path, errno);
+    }
+
+    return ret;
+}
+
+
+static int
+virResctrlMonitorStatsSorter(const void *a,
+                             const void *b)
+{
+    return ((virResctrlMonitorStatsPtr)a)->id
+        - ((virResctrlMonitorStatsPtr)b)->id;
+}
+
+
+/*
+ * virResctrlMonitorGetStats
+ *
+ * @monitor: The monitor that the statistic data will be retrieved from.
+ * @resource: The name for resource name. 'llc_occupancy' for cache resource.
+ * "mbm_total_bytes" and "mbm_local_bytes" for memory bandwidth resource.
+ * @stats: Array of virResctrlMonitorStatsPtr for holding cache or memory
+ * bandwidth usage data.
+ * @nstats: A size_t pointer to hold the returned array length of @stats
+ *
+ * Get cache or memory bandwidth utilization information.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int
+virResctrlMonitorGetStats(virResctrlMonitorPtr monitor,
+                          const char *resource,
+                          virResctrlMonitorStatsPtr *stats,
+                          size_t *nstats)
+{
+    int rv = -1;
+    int ret = -1;
+    DIR *dirp = NULL;
+    char *datapath = NULL;
+    struct dirent *ent = NULL;
+    virResctrlMonitorStatsPtr stat = NULL;
+
+    if (!monitor) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Invalid resctrl monitor"));
+        return -1;
+    }
+
+    if (virAsprintf(&datapath, "%s/mon_data", monitor->path) < 0)
+        return -1;
+
+    if (virDirOpen(&dirp, datapath) < 0)
+        goto cleanup;
+
+    *nstats = 0;
+    while (virDirRead(dirp, &ent, datapath) > 0) {
+        char *node_id = NULL;
+
+        if (VIR_ALLOC(stat) < 0)
+            goto cleanup;
+
+        /* Looking for directory that contains resource utilization
+         * information file. The directory name is arranged in format
+         * "mon_<node_name>_<node_id>". For example, "mon_L3_00" and
+         * "mon_L3_01" are two target directories for a two nodes system
+         * with resource utilization data file for each node respectively.
+         */
+        if (ent->d_type != DT_DIR)
+            continue;
+
+        /* Looking for directory has a prefix 'mon_L' */
+        if (!(node_id = STRSKIP(ent->d_name, "mon_L")))
+            continue;
+
+        /* Looking for directory has another '_' */
+        node_id = strchr(node_id, '_');
+        if (!node_id)
+            continue;
+
+        /* Skip the character '_' */
+        if (!(node_id = STRSKIP(node_id, "_")))
+            continue;
+
+        /* The node ID number should be here, parsing it. */
+        if (virStrToLong_uip(node_id, NULL, 0, &stat->id) < 0)
+            goto cleanup;
+
+        rv = virFileReadValueUint(&stat->val, "%s/%s/%s", datapath,
+                                  ent->d_name, resource);
+        if (rv == -2) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("File '%s/%s/%s' does not exist."),
+                           datapath, ent->d_name, resource);
+        }
+        if (rv < 0)
+            goto cleanup;
+
+        if (VIR_APPEND_ELEMENT(*stats, *nstats, *stat) < 0)
+            goto cleanup;
+    }
+
+    /* Sort in id's ascending order */
+    if (*nstats)
+        qsort(*stats, *nstats, sizeof(*stat), virResctrlMonitorStatsSorter);
+
+    ret = 0;
+ cleanup:
+    VIR_FREE(datapath);
+    VIR_FREE(stat);
+    VIR_DIR_CLOSE(dirp);
+    return ret;
+}
+
+
+/*
+ * virResctrlMonitorGetCacheOccupancy
+ *
+ * @monitor: The monitor that the statistic data will be retrieved from.
+ * @stats: Array of virResctrlMonitorStatsPtr for receiving cache occupancy
+ * data. Caller is responsible to free this array.
+ * @nstats: A size_t pointer to hold the returned array length of @caches
+ *
+ * Get cache or memory bandwidth utilization information.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+
+int
+virResctrlMonitorGetCacheOccupancy(virResctrlMonitorPtr monitor,
+                                   virResctrlMonitorStatsPtr *stats,
+                                   size_t *nstats)
+{
+    return virResctrlMonitorGetStats(monitor, "llc_occupancy",
+                                     stats, nstats);
+}

diff --git a/src/util/virresctrl.h b/src/util/virresctrl.h
index 76e40a243dec1b68d7dd61a4ad143fb93b32113e..45ec9676304e02dab6d9fae7db8ed1688adb36df 100644 (file)
--- a/src/util/virresctrl.h
+++ b/src/util/virresctrl.h
@@ -191,6 +191,13 @@ virResctrlInfoGetMonitorPrefix(virResctrlInfoPtr resctrl,
 typedef struct _virResctrlMonitor virResctrlMonitor;
 typedef virResctrlMonitor *virResctrlMonitorPtr;
 
+typedef struct _virResctrlMonitorStats virResctrlMonitorStats;
+typedef virResctrlMonitorStats *virResctrlMonitorStatsPtr;
+struct _virResctrlMonitorStats {
+    unsigned int id;
+    unsigned int val;
+};
+
 virResctrlMonitorPtr
 virResctrlMonitorNew(void);
 
@@ -205,4 +212,23 @@ virResctrlMonitorAddPID(virResctrlMonitorPtr monitor,
 int
 virResctrlMonitorCreate(virResctrlMonitorPtr monitor,
                         const char *machinename);
+
+int
+virResctrlMonitorSetID(virResctrlMonitorPtr monitor,
+                       const char *id);
+
+const char *
+virResctrlMonitorGetID(virResctrlMonitorPtr monitor);
+
+void
+virResctrlMonitorSetAlloc(virResctrlMonitorPtr monitor,
+                          virResctrlAllocPtr alloc);
+
+int
+virResctrlMonitorRemove(virResctrlMonitorPtr monitor);
+
+int
+virResctrlMonitorGetCacheOccupancy(virResctrlMonitorPtr monitor,
+                                   virResctrlMonitorStatsPtr *caches,
+                                   size_t *ncaches);
 #endif /*  __VIR_RESCTRL_H__ */