[libvirt] [PATCH 5/9] perf: add cpu_migrations software perf event support
John Ferlan
jferlan at redhat.com
Thu Feb 9 21:49:08 UTC 2017
On 01/27/2017 06:01 AM, Nitesh Konkar wrote:
> This patch adds support and documentation
> for the cpu_migrations perf event.
>
> Signed-off-by: Nitesh Konkar <nitkon12 at linux.vnet.ibm.com>
> ---
> docs/formatdomain.html.in | 6 ++++++
> docs/news.xml | 4 ++--
> docs/schemas/domaincommon.rng | 1 +
> include/libvirt/libvirt-domain.h | 9 +++++++++
> src/libvirt-domain.c | 5 ++++-
> src/qemu/qemu_driver.c | 1 +
> src/util/virperf.c | 5 ++++-
> src/util/virperf.h | 1 +
> tests/genericxml2xmlindata/generic-perf.xml | 1 +
> tools/virsh.pod | 4 ++++
> 10 files changed, 33 insertions(+), 4 deletions(-)
>
> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
> index 4ed6e02..f0efab1 100644
> --- a/docs/formatdomain.html.in
> +++ b/docs/formatdomain.html.in
> @@ -1941,6 +1941,7 @@
> <event name='task_clock' enabled='no'/>
> <event name='page_faults' enabled='no'/>
> <event name='context_switches' enabled='no'/>
> + <event name='cpu_migrations' enabled='no'/>
> </perf>
> ...
> </pre>
> @@ -2039,6 +2040,11 @@
> <td>the count of context switches by applications running on the platform</td>
> <td><code>perf.context_switches</code></td>
> </tr>
> + <tr>
> + <td><code>cpu_migrations</code></td>
> + <td>the count of cpu migrations by applications running on the platform</td>
> + <td><code>perf.cpu_migrations</code></td>
> + </tr>
Not sure "count of cpu migrations by applictions" conveys enough
meaning. Is this something applications can control? Is this one of
those things where applications may want to "pin" to [a] specific cpu[s]?
> </table>
>
> <h3><a name="elementsDevices">Devices</a></h3>
> diff --git a/docs/news.xml b/docs/news.xml
> index fb872f5..0489c42 100644
> --- a/docs/news.xml
> +++ b/docs/news.xml
> @@ -137,8 +137,8 @@
> Add support to get the count of branch instructions
> executed, branch misses, bus cycles, stalled frontend
> cpu cycles, stalled backend cpu cycles, ref cpu cycles,
> - cpu clock, task clock, page faults and context switches
> - by applications running on the platform.
> + cpu clock, task clock, page faults, context switches and
> + cpu migrations by applications running on the platform.
Remove news.xml from here.
> </description>
> </change>
> <change>
> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
> index e4e1358..5bd06cb 100644
> --- a/docs/schemas/domaincommon.rng
> +++ b/docs/schemas/domaincommon.rng
> @@ -437,6 +437,7 @@
> <value>task_clock</value>
> <value>page_faults</value>
> <value>context_switches</value>
> + <value>cpu_migrations</value>
> </choice>
> </attribute>
> <attribute name="enabled">
> diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
> index e71bfa7..b4abdb0 100644
> --- a/include/libvirt/libvirt-domain.h
> +++ b/include/libvirt/libvirt-domain.h
> @@ -2228,6 +2228,15 @@ void virDomainStatsRecordListFree(virDomainStatsRecordPtr *stats);
> */
> # define VIR_PERF_PARAM_CONTEXT_SWITCHES "context_switches"
>
> +/**
> + * VIR_PERF_PARAM_CPU_MIGRATIONS:
> + *
> + * Macro for typed parameter name that represents cpu_migrations
> + * perf event which can be used to measure the count of cpu
> + * migrations by applications running on the platform. It corresponds
> + * to the "perf.cpu_migrations" field in the *Stats APIs.
> + */
> +# define VIR_PERF_PARAM_CPU_MIGRATIONS "cpu_migrations"
>
> int virDomainGetPerfEvents(virDomainPtr dom,
> virTypedParameterPtr *params,
> diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
> index 42720f1..d063414 100644
> --- a/src/libvirt-domain.c
> +++ b/src/libvirt-domain.c
> @@ -11255,10 +11255,13 @@ virConnectGetDomainCapabilities(virConnectPtr conn,
> * "perf.task_clock" - The count of task clock as unsigned long long. It is
> * produced by the task_clock perf event.
> * "perf.page_faults" - The count of page faults as unsigned long long. It is
> - * produced by the page_faults perf event.
> + * produced by the page_faults perf event.
> * "perf.context_switches" - The count of context switches as unsigned long
> * long. It is produced by the context_switches
> * perf event.
> + * "perf.cpu_migrations" - The count of cpu migrations as unsigned long
> + * long. It is produced by the cpu_migrations
> + * perf event.
> *
> * Note that entire stats groups or individual stat fields may be missing from
> * the output in case they are not supported by the given hypervisor, are not
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index c579b61..3fb7032 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -9553,6 +9553,7 @@ qemuDomainSetPerfEvents(virDomainPtr dom,
> VIR_PERF_PARAM_TASK_CLOCK, VIR_TYPED_PARAM_BOOLEAN,
> VIR_PERF_PARAM_PAGE_FAULTS, VIR_TYPED_PARAM_BOOLEAN,
> VIR_PERF_PARAM_CONTEXT_SWITCHES, VIR_TYPED_PARAM_BOOLEAN,
> + VIR_PERF_PARAM_CPU_MIGRATIONS, VIR_TYPED_PARAM_BOOLEAN,
> NULL) < 0)
> return -1;
>
> diff --git a/src/util/virperf.c b/src/util/virperf.c
> index c004061..4559845 100644
> --- a/src/util/virperf.c
> +++ b/src/util/virperf.c
> @@ -45,7 +45,7 @@ VIR_ENUM_IMPL(virPerfEvent, VIR_PERF_EVENT_LAST,
> "bus_cycles", "stalled_cycles_frontend",
> "stalled_cycles_backend", "ref_cpu_cycles",
> "cpu_clock", "task_clock", "page_faults",
> - "context_switches");
> + "context_switches", "cpu_migrations");
>
> struct virPerfEvent {
> int type;
> @@ -126,6 +126,9 @@ static struct virPerfEventAttr attrs[] = {
> {.type = VIR_PERF_EVENT_CONTEXT_SWITCHES,
> .attrType = PERF_TYPE_SOFTWARE,
> .attrConfig = PERF_COUNT_SW_CONTEXT_SWITCHES},
> + {.type = VIR_PERF_EVENT_CPU_MIGRATIONS,
> + .attrType = PERF_TYPE_SOFTWARE,
> + .attrConfig = PERF_COUNT_SW_CPU_MIGRATIONS},
> };
> typedef struct virPerfEventAttr *virPerfEventAttrPtr;
>
> diff --git a/src/util/virperf.h b/src/util/virperf.h
> index b937d9a..b769ebc 100644
> --- a/src/util/virperf.h
> +++ b/src/util/virperf.h
> @@ -51,6 +51,7 @@ typedef enum {
> VIR_PERF_EVENT_TASK_CLOCK, /* Count of task clock */
> VIR_PERF_EVENT_PAGE_FAULTS, /* Count of page faults */
> VIR_PERF_EVENT_CONTEXT_SWITCHES, /* Count of context switches */
> + VIR_PERF_EVENT_CPU_MIGRATIONS, /* Count of cpu migrations */
>
> VIR_PERF_EVENT_LAST
> } virPerfEventType;
> diff --git a/tests/genericxml2xmlindata/generic-perf.xml b/tests/genericxml2xmlindata/generic-perf.xml
> index 29a2273..f856318 100644
> --- a/tests/genericxml2xmlindata/generic-perf.xml
> +++ b/tests/genericxml2xmlindata/generic-perf.xml
> @@ -30,6 +30,7 @@
> <event name='task_clock' enabled='yes'/>
> <event name='page_faults' enabled='yes'/>
> <event name='context_switches' enabled='yes'/>
> + <event name='cpu_migrations' enabled='yes'/>
> </perf>
> <devices>
> </devices>
> diff --git a/tools/virsh.pod b/tools/virsh.pod
> index d0bf016..a5e8ccd 100644
> --- a/tools/virsh.pod
> +++ b/tools/virsh.pod
> @@ -950,6 +950,7 @@ I<--perf> returns the statistics of all enabled perf events:
> "perf.task_clock" - the count of task clock
> "perf.page_faults" - the count of page faults
> "perf.context_switches" - the count of context switches
> +"perf.cpu_migrations" - the count of cpu migrations
>
> See the B<perf> command for more details about each event.
>
> @@ -2322,6 +2323,9 @@ B<Valid perf event names>
> running on the platform
> context_switches - Provides the count of context switches by applications
> running on the platform
> + cpu_migrations - Provides the count of cpu migrations, that is, where the
> + process moved from one logical processor to another, by
> + applications running on the platform
and this too goes beyond the 80 column...
John
>
> B<Note>: The statistics can be retrieved using the B<domstats> command using
> the I<--perf> flag.
>
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