[libvirt] [PATCH v2 2/2] qemu: expand domain memory statistics with 'last-update' timestamp

[Derbyshev Dmitriy]

From: Derbyshev Dmitry <dderbyshev at virtuozzo.com>

QEMU reports timestamp along with other memory statistics, but this information is not saved into domain statistics.
It could be useful to determine if the data reported is fresh or not.
Balloon statistics are not reported in hrf, so no modifications are made in qemu_monitor_text.c.

Signed-off-by: Derbyshev Dmitry <dderbyshev at virtuozzo.com>
---
 include/libvirt/libvirt-domain.h |  5 ++++-
 src/libvirt-domain.c             |  2 ++
 src/qemu/qemu_monitor_json.c     | 23 ++++++++++++-----------
 tools/virsh-domain-monitor.c     |  2 ++
 4 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
index b65dd33..8f99516 100644
--- a/include/libvirt/libvirt-domain.h
+++ b/include/libvirt/libvirt-domain.h
@@ -609,11 +609,14 @@ typedef enum {
      */
     VIR_DOMAIN_MEMORY_STAT_USABLE          = 8,
 
+    /* Timestamp of the last update of statistics */
+    VIR_DOMAIN_MEMORY_STAT_LAST_UPDATE     = 9,
+
     /*
      * The number of statistics supported by this version of the interface.
      * To add new statistics, add them to the enum and increase this value.
      */
-    VIR_DOMAIN_MEMORY_STAT_NR              = 9,
+    VIR_DOMAIN_MEMORY_STAT_NR              = 10,
 
 # ifdef VIR_ENUM_SENTINELS
     VIR_DOMAIN_MEMORY_STAT_LAST = VIR_DOMAIN_MEMORY_STAT_NR
diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
index 6ef53a6..be35173 100644
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -5991,6 +5991,8 @@ virDomainGetInterfaceParameters(virDomainPtr domain,
  *     to swap, corresponds to 'Available' in /proc/meminfo
  * VIR_DOMAIN_MEMORY_STAT_ACTUAL_BALLOON:
  *     Current balloon value (in kb).
+ * VIR_DOMAIN_MEMORY_STAT_LAST_UPDATE
+ *     Timestamp of the last statistic
  *
  * Returns: The number of stats provided or -1 in case of failure.
  */
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index aa9762f..ebeb725 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -1602,10 +1602,10 @@ qemuMonitorJSONGetBalloonInfo(qemuMonitorPtr mon,
  * rates and/or whether data has been collected since a previous cycle.
  * It's currently unused.
  */
-#define GET_BALLOON_STATS(FIELD, TAG, DIVISOR)                                \
-    if (virJSONValueObjectHasKey(statsdata, FIELD) &&                         \
+#define GET_BALLOON_STATS(OBJECT, FIELD, TAG, DIVISOR)                        \
+    if (virJSONValueObjectHasKey(OBJECT, FIELD) &&                            \
        (got < nr_stats)) {                                                    \
-        if (virJSONValueObjectGetNumberUlong(statsdata, FIELD, &mem) < 0) {   \
+        if (virJSONValueObjectGetNumberUlong(OBJECT, FIELD, &mem) < 0) {      \
             VIR_DEBUG("Failed to get '%s' value", FIELD);                     \
         } else {                                                              \
             /* Not being collected? No point in providing bad data */         \
@@ -1676,21 +1676,22 @@ int qemuMonitorJSONGetMemoryStats(qemuMonitorPtr mon,
         goto cleanup;
     }
 
-    GET_BALLOON_STATS("stat-swap-in",
+    GET_BALLOON_STATS(statsdata, "stat-swap-in",
                       VIR_DOMAIN_MEMORY_STAT_SWAP_IN, 1024);
-    GET_BALLOON_STATS("stat-swap-out",
+    GET_BALLOON_STATS(statsdata, "stat-swap-out",
                       VIR_DOMAIN_MEMORY_STAT_SWAP_OUT, 1024);
-    GET_BALLOON_STATS("stat-major-faults",
+    GET_BALLOON_STATS(statsdata, "stat-major-faults",
                       VIR_DOMAIN_MEMORY_STAT_MAJOR_FAULT, 1);
-    GET_BALLOON_STATS("stat-minor-faults",
+    GET_BALLOON_STATS(statsdata, "stat-minor-faults",
                       VIR_DOMAIN_MEMORY_STAT_MINOR_FAULT, 1);
-    GET_BALLOON_STATS("stat-free-memory",
+    GET_BALLOON_STATS(statsdata, "stat-free-memory",
                       VIR_DOMAIN_MEMORY_STAT_UNUSED, 1024);
-    GET_BALLOON_STATS("stat-total-memory",
+    GET_BALLOON_STATS(statsdata, "stat-total-memory",
                       VIR_DOMAIN_MEMORY_STAT_AVAILABLE, 1024);
-    GET_BALLOON_STATS("available",
+    GET_BALLOON_STATS(statsdata, "available",
                       VIR_DOMAIN_MEMORY_STAT_USABLE, 1024);
-
+    GET_BALLOON_STATS(data, "last-update",
+                      VIR_DOMAIN_MEMORY_STAT_LAST_UPDATE, 1);
 
  cleanup:
     virJSONValueFree(cmd);
diff --git a/tools/virsh-domain-monitor.c b/tools/virsh-domain-monitor.c
index 1921ff5..b4ccbf6 100644
--- a/tools/virsh-domain-monitor.c
+++ b/tools/virsh-domain-monitor.c
@@ -375,6 +375,8 @@ cmdDomMemStat(vshControl *ctl, const vshCmd *cmd)
             vshPrint(ctl, "actual %llu\n", stats[i].val);
         if (stats[i].tag == VIR_DOMAIN_MEMORY_STAT_RSS)
             vshPrint(ctl, "rss %llu\n", stats[i].val);
+        if (stats[i].tag == VIR_DOMAIN_MEMORY_STAT_LAST_UPDATE)
+            vshPrint(ctl, "last_update %llu\n", stats[i].val);
     }
 
     ret = true;
-- 
1.9.5.msysgit.0