Re: [libvirt] [PATCH v7 2/7] qemu: expand domain memory statistics with 'usable'

From: Derbyshev Dmitry <dderbyshev(a)virtuozzo.com&gt; Currently 'memtotal' in virtio drivers and qemu corresponds to 'available' in libvirt. Because of that we introduce libvirt 'usable' parameter, which maps to 'stat-available-memory' balloon statistics. As balloon statistics isn't reported in hmp, so no modification is made in qemu_monitor_text.c. Signed-off-by: Derbyshev Dmitry <dderbyshev(a)virtuozzo.com&gt; --- include/libvirt/libvirt-domain.h | 8 +++++++- src/libvirt-domain.c | 3 +++ src/qemu/qemu_monitor_json.c | 4 ++++ tools/virsh-domain-monitor.c | 2 ++ tools/virsh.pod | 2 ++ 5 files changed, 18 insertions(+), 1 deletion(-) diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h index 7ea93aa..3fb482b 100644 --- a/include/libvirt/libvirt-domain.h +++ b/include/libvirt/libvirt-domain.h @@ -604,10 +604,16 @@ typedef enum { VIR_DOMAIN_MEMORY_STAT_RSS = 7, /* + * How big the balloon can be inflated without pushing the guest system

+ * to swap, corresponds to 'Available' in /proc/meminfo + */ + VIR_DOMAIN_MEMORY_STAT_USABLE = 8, + + /* * 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 = 8, + VIR_DOMAIN_MEMORY_STAT_NR = 9, # 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 4e71a94..1467030 100644 --- a/src/libvirt-domain.c +++ b/src/libvirt-domain.c @@ -5986,6 +5986,9 @@ virDomainGetInterfaceParameters(virDomainPtr domain, * The amount of memory which is not being used for any purpose (in kb). * VIR_DOMAIN_MEMORY_STAT_AVAILABLE: * The total amount of memory available to the domain's OS (in kb). + * VIR_DOMAIN_MEMORY_STAT_USABLE: + * How big the balloon can be inflated without pushing the guest system

+ * to swap, corresponds to 'Available' in /proc/meminfo * VIR_DOMAIN_MEMORY_STAT_ACTUAL_BALLOON: * Current balloon value (in kb). * diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index bb426dc..c83e0cc 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -1719,7 +1719,11 @@ int qemuMonitorJSONGetMemoryStats(qemuMonitorPtr mon, VIR_DOMAIN_MEMORY_STAT_UNUSED, 1024); GET_BALLOON_STATS("stat-total-memory", VIR_DOMAIN_MEMORY_STAT_AVAILABLE, 1024); + GET_BALLOON_STATS("stat-available-memory", + VIR_DOMAIN_MEMORY_STAT_USABLE, 1024); + ret = got; + cleanup: virJSONValueFree(cmd); virJSONValueFree(reply); diff --git a/tools/virsh-domain-monitor.c b/tools/virsh-domain-monitor.c index c712fa5..7f30da2 100644 --- a/tools/virsh-domain-monitor.c +++ b/tools/virsh-domain-monitor.c @@ -369,6 +369,8 @@ cmdDomMemStat(vshControl *ctl, const vshCmd *cmd) vshPrint(ctl, "unused %llu\n", stats[i].val); if (stats[i].tag == VIR_DOMAIN_MEMORY_STAT_AVAILABLE) vshPrint(ctl, "available %llu\n", stats[i].val); + if (stats[i].tag == VIR_DOMAIN_MEMORY_STAT_USABLE) + vshPrint(ctl, "usable %llu\n", stats[i].val); if (stats[i].tag == VIR_DOMAIN_MEMORY_STAT_ACTUAL_BALLOON) vshPrint(ctl, "actual %llu\n", stats[i].val); if (stats[i].tag == VIR_DOMAIN_MEMORY_STAT_RSS) diff --git a/tools/virsh.pod b/tools/virsh.pod index 4ebf7ad..5444f91 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -819,6 +819,8 @@ B<Explanation of fields>: available - The amount of usable memory as seen by the domain (in kB) actual - Current balloon value (in KB) rss - Resident Set Size of the running domain's process (in kB) + usable - The amount of memory which can be reclaimed by balloon

+without causing host swapping (in KB) For QEMU/KVM with a memory balloon, setting the optional I<--period> to a value larger than 0 in seconds will allow the balloon driver to return