[libvirt] [PATCH 7/9] perf: add page_faults_maj software perf event support
John Ferlan
jferlan at redhat.com
Thu Feb 9 21:52:39 UTC 2017
On 01/27/2017 06:01 AM, Nitesh Konkar wrote:
> This patch adds support and documentation
> for the page_faults_maj perf event.
>
> Signed-off-by: Nitesh Konkar <nitkon12 at linux.vnet.ibm.com>
> ---
> docs/formatdomain.html.in | 7 +++++++
> docs/news.xml | 4 ++--
> docs/schemas/domaincommon.rng | 1 +
> include/libvirt/libvirt-domain.h | 10 ++++++++++
> src/libvirt-domain.c | 3 +++
> 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 | 5 +++++
> 10 files changed, 35 insertions(+), 3 deletions(-)
>
NB: Similar comments from the page_faults_min...
> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
> index 1857168..50a6bdb 100644
> --- a/docs/formatdomain.html.in
> +++ b/docs/formatdomain.html.in
> @@ -1943,6 +1943,7 @@
> <event name='context_switches' enabled='no'/>
> <event name='cpu_migrations' enabled='no'/>
> <event name='page_faults_min' enabled='no'/>
> + <event name='page_faults_maj' enabled='no'/>
> </perf>
> ...
> </pre>
> @@ -2052,6 +2053,12 @@
> platform</td>
> <td><code>perf.page_faults_min</code></td>
> </tr>
> + <tr>
> + <td><code>page_faults_maj</code></td>
> + <td>the count of major page faults by applications running on the
> + platform</td>
> + <td><code>perf.page_faults_maj</code></td>
> + </tr>
As already noted in patch 3... is maj+min the same as what patch 3 provides?
Thus are all necessary?
> </table>
>
> <h3><a name="elementsDevices">Devices</a></h3>
> diff --git a/docs/news.xml b/docs/news.xml
> index 0e7c0d2..fe533f2 100644
> --- a/docs/news.xml
> +++ b/docs/news.xml
> @@ -138,8 +138,8 @@
> executed, branch misses, bus cycles, stalled frontend
> cpu cycles, stalled backend cpu cycles, ref cpu cycles,
> cpu clock, task clock, page faults, context switches,
> - cpu migrations and page faults min by applications
> - running on the platform.
> + cpu migrations, page faults min and page faults maj by
> + applications running on the platform.
Remove news.xml
> </description>
> </change>
> <change>
> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
> index f30ec0d..5f986d6 100644
> --- a/docs/schemas/domaincommon.rng
> +++ b/docs/schemas/domaincommon.rng
> @@ -439,6 +439,7 @@
> <value>context_switches</value>
> <value>cpu_migrations</value>
> <value>page_faults_min</value>
> + <value>page_faults_maj</value>
> </choice>
> </attribute>
> <attribute name="enabled">
> diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
> index 108591a..d16200f 100644
> --- a/include/libvirt/libvirt-domain.h
> +++ b/include/libvirt/libvirt-domain.h
> @@ -2248,6 +2248,16 @@ void virDomainStatsRecordListFree(virDomainStatsRecordPtr *stats);
> */
> # define VIR_PERF_PARAM_PAGE_FAULTS_MIN "page_faults_min"
>
> +/**
> + * VIR_PERF_PARAM_PAGE_FAULTS_MAJ:
> + *
> + * Macro for typed parameter name that represents page_faults_maj
> + * perf event which can be used to measure the count of major page
> + * faults by applications running on the platform. It corresponds
> + * to the "perf.page_faults_maj" field in the *Stats APIs.
> + */
> +# define VIR_PERF_PARAM_PAGE_FAULTS_MAJ "page_faults_maj"
> +
> int virDomainGetPerfEvents(virDomainPtr dom,
> virTypedParameterPtr *params,
> int *nparams,
> diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
> index 1be385e..1d7c181 100644
> --- a/src/libvirt-domain.c
> +++ b/src/libvirt-domain.c
> @@ -11265,6 +11265,9 @@ virConnectGetDomainCapabilities(virConnectPtr conn,
> * "perf.page_faults_min" - The count of minor page faults as unsigned long
> * long. It is produced by the page_faults_min
> * perf event.
> + * "perf.page_faults_maj" - The count of major page faults as unsigned long
> + * long. It is produced by the page_faults_maj
> + * 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 4f24fa6..c88bf5a 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -9555,6 +9555,7 @@ qemuDomainSetPerfEvents(virDomainPtr dom,
> VIR_PERF_PARAM_CONTEXT_SWITCHES, VIR_TYPED_PARAM_BOOLEAN,
> VIR_PERF_PARAM_CPU_MIGRATIONS, VIR_TYPED_PARAM_BOOLEAN,
> VIR_PERF_PARAM_PAGE_FAULTS_MIN, VIR_TYPED_PARAM_BOOLEAN,
> + VIR_PERF_PARAM_PAGE_FAULTS_MAJ, VIR_TYPED_PARAM_BOOLEAN,
> NULL) < 0)
> return -1;
>
> diff --git a/src/util/virperf.c b/src/util/virperf.c
> index c839b04..37f61e2 100644
> --- a/src/util/virperf.c
> +++ b/src/util/virperf.c
> @@ -46,7 +46,7 @@ VIR_ENUM_IMPL(virPerfEvent, VIR_PERF_EVENT_LAST,
> "stalled_cycles_backend", "ref_cpu_cycles",
> "cpu_clock", "task_clock", "page_faults",
> "context_switches", "cpu_migrations",
> - "page_faults_min");
> + "page_faults_min", "page_faults_maj");
>
> struct virPerfEvent {
> int type;
> @@ -133,6 +133,9 @@ static struct virPerfEventAttr attrs[] = {
> {.type = VIR_PERF_EVENT_PAGE_FAULTS_MIN,
> .attrType = PERF_TYPE_SOFTWARE,
> .attrConfig = PERF_COUNT_SW_PAGE_FAULTS_MIN},
> + {.type = VIR_PERF_EVENT_PAGE_FAULTS_MAJ,
> + .attrType = PERF_TYPE_SOFTWARE,
> + .attrConfig = PERF_COUNT_SW_PAGE_FAULTS_MAJ},
> };
> typedef struct virPerfEventAttr *virPerfEventAttrPtr;
>
> diff --git a/src/util/virperf.h b/src/util/virperf.h
> index aec352b..e99c870 100644
> --- a/src/util/virperf.h
> +++ b/src/util/virperf.h
> @@ -53,6 +53,7 @@ typedef enum {
> VIR_PERF_EVENT_CONTEXT_SWITCHES, /* Count of context switches */
> VIR_PERF_EVENT_CPU_MIGRATIONS, /* Count of cpu migrations */
> VIR_PERF_EVENT_PAGE_FAULTS_MIN, /* Count of minor page faults */
> + VIR_PERF_EVENT_PAGE_FAULTS_MAJ, /* Count of major page faults */
>
> VIR_PERF_EVENT_LAST
> } virPerfEventType;
> diff --git a/tests/genericxml2xmlindata/generic-perf.xml b/tests/genericxml2xmlindata/generic-perf.xml
> index 62ad973..a5b6dfb 100644
> --- a/tests/genericxml2xmlindata/generic-perf.xml
> +++ b/tests/genericxml2xmlindata/generic-perf.xml
> @@ -32,6 +32,7 @@
> <event name='context_switches' enabled='yes'/>
> <event name='cpu_migrations' enabled='yes'/>
> <event name='page_faults_min' enabled='yes'/>
> + <event name='page_faults_maj' enabled='yes'/>
> </perf>
> <devices>
> </devices>
> diff --git a/tools/virsh.pod b/tools/virsh.pod
> index 4eb689e..d6bec4d 100644
> --- a/tools/virsh.pod
> +++ b/tools/virsh.pod
> @@ -952,6 +952,7 @@ I<--perf> returns the statistics of all enabled perf events:
> "perf.context_switches" - the count of context switches
> "perf.cpu_migrations" - the count of cpu migrations
> "perf.page_faults_min" - the count of minor page faults
> +"perf.page_faults_maj" - the count of major page faults
>
> See the B<perf> command for more details about each event.
>
> @@ -2331,6 +2332,10 @@ B<Valid perf event names>
> the page was present in the page cache, and therefore the
> fault avoided loading it from storage, by applications
> running on the platform
> + page_faults_maj - Provides the count of major page faults, that is, where
> + the page was not present in the page cache, and therefore
> + had to be fetched from storage, by applications
> + running on the platform
The min/maj descriptions here are a bit more wordy. It does help, but I
wonder now is this the wrong place. That is should the longer
description be in the API so that the rendered API docs get a nice long
description and the virsh output remains somewhat terse.
It really is up to you to decide, but I'm leaning towards better API doc
descriptions...
John
>
> B<Note>: The statistics can be retrieved using the B<domstats> command using
> the I<--perf> flag.
>
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