[libvirt] [PATCH v2 1/1] qemu: add entry for balloon stat stat-disk-caches

[Tomáš Golembiovský]

Signed-off-by: Tomáš Golembiovský <tgolembi at redhat.com>
---
 include/libvirt/libvirt-domain.h | 9 ++++++++-
 src/libvirt-domain.c             | 3 +++
 src/qemu/qemu_monitor_json.c     | 2 ++
 tools/virsh-domain-monitor.c     | 2 ++
 4 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
index da773b76cb..b96c018a90 100644
--- a/include/libvirt/libvirt-domain.h
+++ b/include/libvirt/libvirt-domain.h
@@ -628,11 +628,18 @@ typedef enum {
     /* Timestamp of the last update of statistics, in seconds. */
     VIR_DOMAIN_MEMORY_STAT_LAST_UPDATE     = 9,
 
+    /*
+     * The amount of memory, in bytes, that can be quickly reclaimed without
+     * additional I/O. Typically these pages are used for caching files from
+     * disk.
+     */
+    VIR_DOMAIN_MEMORY_STAT_DISK_CACHES     = 10,
+
     /*
      * 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              = 10,
+    VIR_DOMAIN_MEMORY_STAT_NR              = 11,
 
 # 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 d44b553c74..ca22d13568 100644
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -5732,6 +5732,9 @@ virDomainGetInterfaceParameters(virDomainPtr domain,
  *     Current balloon value (in kb).
  * VIR_DOMAIN_MEMORY_STAT_LAST_UPDATE
  *     Timestamp of the last statistic
+ * VIR_DOMAIN_MEMORY_STAT_DISK_CACHES
+ *     Memory that can be reclaimed without additional I/O, typically disk
+ *     caches (in kb).
  *
  * 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 e8a46d2ec3..d62d979b5a 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -2071,6 +2071,8 @@ int qemuMonitorJSONGetMemoryStats(qemuMonitorPtr mon,
                       VIR_DOMAIN_MEMORY_STAT_USABLE, 1024);
     GET_BALLOON_STATS(data, "last-update",
                       VIR_DOMAIN_MEMORY_STAT_LAST_UPDATE, 1);
+    GET_BALLOON_STATS(statsdata, "stat-disk-caches",
+                      VIR_DOMAIN_MEMORY_STAT_DISK_CACHES, 1024);
     ret = got;
  cleanup:
     virJSONValueFree(cmd);
diff --git a/tools/virsh-domain-monitor.c b/tools/virsh-domain-monitor.c
index 8cbb3db37c..bad882e87c 100644
--- a/tools/virsh-domain-monitor.c
+++ b/tools/virsh-domain-monitor.c
@@ -362,6 +362,8 @@ 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_DISK_CACHES)
+            vshPrint(ctl, "disk_caches %llu\n", stats[i].val);
         if (stats[i].tag == VIR_DOMAIN_MEMORY_STAT_LAST_UPDATE)
             vshPrint(ctl, "last_update %llu\n", stats[i].val);
     }
-- 
2.17.0