[libvirt] [PATCH 3/9] perf: add page_faults software perf event support
John Ferlan
jferlan at redhat.com
Thu Feb 9 21:45:48 UTC 2017
On 01/27/2017 06:01 AM, Nitesh Konkar wrote:
> This patch adds support and documentation
> for the page_faults 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 | 11 +++++++++++
> src/libvirt-domain.c | 2 ++
> src/qemu/qemu_driver.c | 1 +
> src/util/virperf.c | 7 +++++--
> src/util/virperf.h | 1 +
> tests/genericxml2xmlindata/generic-perf.xml | 1 +
> tools/virsh.pod | 3 +++
> 10 files changed, 33 insertions(+), 4 deletions(-)
>
> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
> index 1ed5db7..2071eea 100644
> --- a/docs/formatdomain.html.in
> +++ b/docs/formatdomain.html.in
> @@ -1939,6 +1939,7 @@
> <event name='ref_cpu_cycles' enabled='no'/>
> <event name='cpu_clock' enabled='no'/>
> <event name='task_clock' enabled='no'/>
> + <event name='page_faults' enabled='no'/>
> </perf>
> ...
> </pre>
> @@ -2027,6 +2028,11 @@
> <td>the count of task clock by applications running on the platform</td>
> <td><code>perf.task_clock</code></td>
> </tr>
> + <tr>
> + <td><code>page_faults</code></td>
> + <td>the count of page faults by applications running on the platform</td>
> + <td><code>perf.page_faults</code></td>
> + </tr>
Curious why "page_faults" and "page_faults_min" & "page_faults_maj" is
"min+maj" equal to this value?
A nit, I've seen wording like "page faults incurred" used too.. Just a
bit more descriptive
> </table>
>
> <h3><a name="elementsDevices">Devices</a></h3>
> diff --git a/docs/news.xml b/docs/news.xml
> index 38373c0..14beed6 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 and task clock by applications running on the
> - platform.
> + cpu clock, task clock and page faults by applications
> + running on the platform.
Similar with the news.xml to previous...
> </description>
> </change>
> <change>
> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
> index 6ee2c6f..a7727e7 100644
> --- a/docs/schemas/domaincommon.rng
> +++ b/docs/schemas/domaincommon.rng
> @@ -435,6 +435,7 @@
> <value>ref_cpu_cycles</value>
> <value>cpu_clock</value>
> <value>task_clock</value>
> + <value>page_faults</value>
> </choice>
> </attribute>
> <attribute name="enabled">
> diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
> index f4f1c74..36619b5 100644
> --- a/include/libvirt/libvirt-domain.h
> +++ b/include/libvirt/libvirt-domain.h
> @@ -2208,6 +2208,17 @@ void virDomainStatsRecordListFree(virDomainStatsRecordPtr *stats);
> */
> # define VIR_PERF_PARAM_TASK_CLOCK "task_clock"
>
> +/**
> +* VIR_PERF_PARAM_PAGE_FAULTS:
> +*
> +* Macro for typed parameter name that represents page_faults
> +* perf event which can be used to measure the count of page
> +* faults by applications running on the platform. It corresponds
> +* to the "perf.page_faults" field in the *Stats APIs.
> +*/
> +# define VIR_PERF_PARAM_PAGE_FAULTS "page_faults"
> +
> +
> int virDomainGetPerfEvents(virDomainPtr dom,
> virTypedParameterPtr *params,
> int *nparams,
> diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
> index 6875848..a923acc 100644
> --- a/src/libvirt-domain.c
> +++ b/src/libvirt-domain.c
> @@ -11254,6 +11254,8 @@ virConnectGetDomainCapabilities(virConnectPtr conn,
> * produced by the cpu_clock perf event.
> * "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.
> *
> * 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 285156d..88f649e 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -9551,6 +9551,7 @@ qemuDomainSetPerfEvents(virDomainPtr dom,
> VIR_PERF_PARAM_REF_CPU_CYCLES, VIR_TYPED_PARAM_BOOLEAN,
> VIR_PERF_PARAM_CPU_CLOCK, VIR_TYPED_PARAM_BOOLEAN,
> VIR_PERF_PARAM_TASK_CLOCK, VIR_TYPED_PARAM_BOOLEAN,
> + VIR_PERF_PARAM_PAGE_FAULTS, VIR_TYPED_PARAM_BOOLEAN,
> NULL) < 0)
> return -1;
>
> diff --git a/src/util/virperf.c b/src/util/virperf.c
> index e19cfea..3282aca 100644
> --- a/src/util/virperf.c
> +++ b/src/util/virperf.c
> @@ -44,7 +44,7 @@ VIR_ENUM_IMPL(virPerfEvent, VIR_PERF_EVENT_LAST,
> "branch_instructions", "branch_misses",
> "bus_cycles", "stalled_cycles_frontend",
> "stalled_cycles_backend", "ref_cpu_cycles",
> - "cpu_clock", "task_clock");
> + "cpu_clock", "task_clock", "page_faults");
>
> struct virPerfEvent {
> int type;
> @@ -118,7 +118,10 @@ static struct virPerfEventAttr attrs[] = {
> .attrConfig = PERF_COUNT_SW_CPU_CLOCK},
> {.type = VIR_PERF_EVENT_TASK_CLOCK,
> .attrType = PERF_TYPE_SOFTWARE,
> - .attrConfig = PERF_COUNT_SW_TASK_CLOCK}
> + .attrConfig = PERF_COUNT_SW_TASK_CLOCK},
> + {.type = VIR_PERF_EVENT_PAGE_FAULTS,
> + .attrType = PERF_TYPE_SOFTWARE,
> + .attrConfig = PERF_COUNT_SW_PAGE_FAULTS},
> };
> typedef struct virPerfEventAttr *virPerfEventAttrPtr;
>
> diff --git a/src/util/virperf.h b/src/util/virperf.h
> index b9e8a75..fbc5ae3 100644
> --- a/src/util/virperf.h
> +++ b/src/util/virperf.h
> @@ -49,6 +49,7 @@ typedef enum {
> VIR_PERF_EVENT_REF_CPU_CYCLES, /* Count of ref cpu cycles */
> VIR_PERF_EVENT_CPU_CLOCK, /* Count of cpu clock */
> VIR_PERF_EVENT_TASK_CLOCK, /* Count of task clock */
> + VIR_PERF_EVENT_PAGE_FAULTS, /* Count of page faults */
>
> VIR_PERF_EVENT_LAST
> } virPerfEventType;
> diff --git a/tests/genericxml2xmlindata/generic-perf.xml b/tests/genericxml2xmlindata/generic-perf.xml
> index 5ebc0a2..3f27887 100644
> --- a/tests/genericxml2xmlindata/generic-perf.xml
> +++ b/tests/genericxml2xmlindata/generic-perf.xml
> @@ -28,6 +28,7 @@
> <event name='ref_cpu_cycles' enabled='yes'/>
> <event name='cpu_clock' enabled='yes'/>
> <event name='task_clock' enabled='yes'/>
> + <event name='page_faults' enabled='yes'/>
> </perf>
> <devices>
> </devices>
> diff --git a/tools/virsh.pod b/tools/virsh.pod
> index 958e473..f7be74e 100644
> --- a/tools/virsh.pod
> +++ b/tools/virsh.pod
> @@ -948,6 +948,7 @@ I<--perf> returns the statistics of all enabled perf events:
> "perf.ref_cpu_cycles" - the count of ref cpu cycles
> "perf.cpu_clock" - the count of cpu clock
> "perf.task_clock" - the count of task clock
> +"perf.page_faults" - the count of page faults
>
> See the B<perf> command for more details about each event.
>
> @@ -2316,6 +2317,8 @@ B<Valid perf event names>
> running on the platform.
> task_clock - Provides the task clock time consumed by applications
> running on the platform
> + page_faults - Provides the count of page faults by applications
> + running on the platform
Interesting that the maj and min descriptions are quite wordy, but this
one isn't... I'm assuming to a degree the count the same thing, right?
John
>
> B<Note>: The statistics can be retrieved using the B<domstats> command using
> the I<--perf> flag.
>
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