Add support for reading the iothread poll-weight value from QEMU and exposing it via domain stats. Add poll_weight and set_poll_weight fields to qemuMonitorIOThreadInfo and parse the poll-weight property from the QMP query-iothreads response. The property is optional and only present on newer QEMU binaries. Expose the fetched value through the domain stats interface by adding VIR_DOMAIN_STATS_IOTHREAD_SUFFIX_POLL_WEIGHT and reporting it in qemuDomainGetStatsIOThread when the value is available. Signed-off-by: Jaehoon Kim <jhkim@linux.ibm.com> --- docs/manpages/virsh.rst | 2 ++ include/libvirt/libvirt-domain.h | 10 ++++++++++ src/qemu/qemu_driver.c | 5 +++++ src/qemu/qemu_monitor.h | 2 ++ src/qemu/qemu_monitor_json.c | 5 +++++ 5 files changed, 24 insertions(+) diff --git a/docs/manpages/virsh.rst b/docs/manpages/virsh.rst index a10d29e0ea..8465f19c12 100644 --- a/docs/manpages/virsh.rst +++ b/docs/manpages/virsh.rst @@ -2905,6 +2905,8 @@ not available for statistical purposes. growth is managed by the hypervisor. * ``iothread.<id>.poll-shrink`` - polling time shrink value. A value of (zero) indicates shrink is managed by hypervisor. +* ``iothread.<id>.poll-weight`` - polling weight shift value. A value of 0 + (zero) indicates the hypervisor's default weight is used. *--memory* returns: diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h index f4dfe9fb1a..bb524f41ee 100644 --- a/include/libvirt/libvirt-domain.h +++ b/include/libvirt/libvirt-domain.h @@ -4330,6 +4330,16 @@ struct _virDomainStatsRecord { */ # define VIR_DOMAIN_STATS_IOTHREAD_SUFFIX_POLL_SHRINK ".poll-shrink" +/** + * VIR_DOMAIN_STATS_IOTHREAD_SUFFIX_POLL_WEIGHT: + * + * Polling weight factor as an unsigned int. This shift value controls how + * much the most recent event interval affects adaptive polling calculations. + * A 0 (zero) indicates the hypervisor's default weight is used. + * + * Since: 12.7.0 + */ +# define VIR_DOMAIN_STATS_IOTHREAD_SUFFIX_POLL_WEIGHT ".poll-weight" /** * VIR_DOMAIN_STATS_MEMORY_BANDWIDTH_MONITOR_COUNT: diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 44b41726fb..842b56a2c2 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -18411,6 +18411,11 @@ qemuDomainGetStatsIOThread(virQEMUDriver *driver G_GNUC_UNUSED, VIR_DOMAIN_STATS_IOTHREAD_PREFIX "%u" VIR_DOMAIN_STATS_IOTHREAD_SUFFIX_POLL_SHRINK, iothreads[i]->iothread_id); } + if (iothreads[i]->set_poll_weight) { + virTypedParamListAddUInt(params, iothreads[i]->poll_weight, + VIR_DOMAIN_STATS_IOTHREAD_PREFIX "%u" VIR_DOMAIN_STATS_IOTHREAD_SUFFIX_POLL_WEIGHT, + iothreads[i]->iothread_id); + } } for (i = 0; i < niothreads; i++) diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index 3298095e9c..e560618bf4 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -1583,11 +1583,13 @@ struct _qemuMonitorIOThreadInfo { unsigned long long poll_max_ns; unsigned long long poll_grow; unsigned long long poll_shrink; + unsigned int poll_weight; int thread_pool_min; int thread_pool_max; bool set_poll_max_ns; bool set_poll_grow; bool set_poll_shrink; + bool set_poll_weight; bool set_thread_pool_min; bool set_thread_pool_max; }; diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index af9a77ed3b..b02c0722d9 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -7202,6 +7202,11 @@ qemuMonitorJSONGetIOThreads(qemuMonitor *mon, virJSONValueObjectGetNumberUlong(child, "poll-shrink", &info->poll_shrink) == 0) info->poll_valid = true; + + /* poll-weight is optional, only present on newer QEMU */ + if (virJSONValueObjectGetNumberUint(child, "poll-weight", + &info->poll_weight) == 0) + info->set_poll_weight = true; } *niothreads = n; -- 2.54.0