[patch] perf_event_open.2: Exclude_host/exclude_guest clarification

[patch] perf_event_open.2: Exclude_host/exclude_guest clarification

[Vince Weaver]

This patch relates to the exclude_host and exclude_guest bits added 
by the  following commit:

   exclude_host, exclude_guest; Linux 3.2
        commit a240f76165e6255384d4bdb8139895fac7988799
        Author: Joerg Roedel <joerg.roedel-5C7GfCeVMHo@public.gmane.org>
        Date:   Wed Oct 5 14:01:16 2011 +0200

            perf, core: Introduce attrs to count in either host or guest mode

            Signed-off-by: Joerg Roedel <joerg.roedel-5C7GfCeVMHo@public.gmane.org>
            Signed-off-by: Gleb Natapov <gleb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
            Signed-off-by: Peter Zijlstra <a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org>
            Link: http://lkml.kernel.org/r/1317816084-18026-2-git-send-email-gleb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
            Signed-off-by: Ingo Molnar <mingo-X9Un+BFzKDI@public.gmane.org>

The updated manpage text clarifies that the "exclude_host" and
"exclude_guest" perf_event_open() attr bits only apply in the 
context of a KVM environment and are currently x86 only.

This is a resend of the patch; the previous time I sent it
(http://thread.gmane.org/gmane.linux.man/7500) it did not
receive any comments.

Signed-off-by: Vince Weaver <vincent.weaver-e7X0jjDqjFGHXe+LvDLADg@public.gmane.org>

diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
index 39c8d8c..1ea56c9 100644
--- a/man2/perf_event_open.2
+++ b/man2/perf_event_open.2
@@ -1006,11 +1006,25 @@ struct sample_id {
 .TP
 .IR "exclude_host" " (since Linux 3.2)"
 .\" commit a240f76165e6255384d4bdb8139895fac7988799
-Do not measure time spent in VM host.
+When conducting measurements that include processes running
+VM instances (i.e. have executed a
+.I KVM_RUN
+.BR ioctl (2)
+) only measure events happening inside a guest instance.
+This is only meaningful outside the guests; this setting does
+not change counts gathered inside of a guest.
+Currently this functionality is x86 only.
 .TP
 .IR "exclude_guest" " (since Linux 3.2)"
 .\" commit a240f76165e6255384d4bdb8139895fac7988799
-Do not measure time spent in VM guest.
+When conducting measurements that include processes running
+VM instances (i.e. have executed a
+.I KVM_RUN
+.BR ioctl (2)
+) do not measure events happening inside guest instances.
+This is only meaningful outside the guests; this setting does
+not change counts gathered inside of a guest.
+Currently this functionality is x86 only.
 .TP
 .IR "exclude_callchain_kernel" " (since Linux 3.7)"
 .\" commit d077526485d5c9b12fe85d0b2b3b7041e6bc5f91
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Re: [patch] perf_event_open.2: Exclude_host/exclude_guest clarification

[Michael Kerrisk (man-pages)]

Hi Joerg,

Would you be willing to review/comment on Vince's patch, please.

Cheers,

Michael

On 02/11/2015 08:06 PM, Vince Weaver wrote:
> 
> This patch relates to the exclude_host and exclude_guest bits added 
> by the  following commit:
> 
>    exclude_host, exclude_guest; Linux 3.2
>         commit a240f76165e6255384d4bdb8139895fac7988799
>         Author: Joerg Roedel <joerg.roedel-5C7GfCeVMHo@public.gmane.org>
>         Date:   Wed Oct 5 14:01:16 2011 +0200
> 
>             perf, core: Introduce attrs to count in either host or guest mode
> 
>             Signed-off-by: Joerg Roedel <joerg.roedel-5C7GfCeVMHo@public.gmane.org>
>             Signed-off-by: Gleb Natapov <gleb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>             Signed-off-by: Peter Zijlstra <a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org>
>             Link: http://lkml.kernel.org/r/1317816084-18026-2-git-send-email-gleb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
>             Signed-off-by: Ingo Molnar <mingo-X9Un+BFzKDI@public.gmane.org>
> 
> The updated manpage text clarifies that the "exclude_host" and
> "exclude_guest" perf_event_open() attr bits only apply in the 
> context of a KVM environment and are currently x86 only.
> 
> This is a resend of the patch; the previous time I sent it
> (http://thread.gmane.org/gmane.linux.man/7500) it did not
> receive any comments.
> 
> Signed-off-by: Vince Weaver <vincent.weaver-e7X0jjDqjFGHXe+LvDLADg@public.gmane.org>
> 
> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
> index 39c8d8c..1ea56c9 100644
> --- a/man2/perf_event_open.2
> +++ b/man2/perf_event_open.2
> @@ -1006,11 +1006,25 @@ struct sample_id {
>  .TP
>  .IR "exclude_host" " (since Linux 3.2)"
>  .\" commit a240f76165e6255384d4bdb8139895fac7988799
> -Do not measure time spent in VM host.
> +When conducting measurements that include processes running
> +VM instances (i.e. have executed a
> +.I KVM_RUN
> +.BR ioctl (2)
> +) only measure events happening inside a guest instance.
> +This is only meaningful outside the guests; this setting does
> +not change counts gathered inside of a guest.
> +Currently this functionality is x86 only.
>  .TP
>  .IR "exclude_guest" " (since Linux 3.2)"
>  .\" commit a240f76165e6255384d4bdb8139895fac7988799
> -Do not measure time spent in VM guest.
> +When conducting measurements that include processes running
> +VM instances (i.e. have executed a
> +.I KVM_RUN
> +.BR ioctl (2)
> +) do not measure events happening inside guest instances.
> +This is only meaningful outside the guests; this setting does
> +not change counts gathered inside of a guest.
> +Currently this functionality is x86 only.
>  .TP
>  .IR "exclude_callchain_kernel" " (since Linux 3.7)"
>  .\" commit d077526485d5c9b12fe85d0b2b3b7041e6bc5f91
> 


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
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Re: [patch] perf_event_open.2: Exclude_host/exclude_guest clarification

[Michael Kerrisk (man-pages)]

Hello Joerg,

Ping!

Cheers,

Michael

On 02/17/2015 06:32 AM, Michael Kerrisk (man-pages) wrote:
> Hi Joerg,
> 
> Would you be willing to review/comment on Vince's patch, please.
> 
> Cheers,
> 
> Michael
> 
> On 02/11/2015 08:06 PM, Vince Weaver wrote:
>>
>> This patch relates to the exclude_host and exclude_guest bits added 
>> by the  following commit:
>>
>>    exclude_host, exclude_guest; Linux 3.2
>>         commit a240f76165e6255384d4bdb8139895fac7988799
>>         Author: Joerg Roedel <joerg.roedel-5C7GfCeVMHo@public.gmane.org>
>>         Date:   Wed Oct 5 14:01:16 2011 +0200
>>
>>             perf, core: Introduce attrs to count in either host or guest mode
>>
>>             Signed-off-by: Joerg Roedel <joerg.roedel-5C7GfCeVMHo@public.gmane.org>
>>             Signed-off-by: Gleb Natapov <gleb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>>             Signed-off-by: Peter Zijlstra <a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org>
>>             Link: http://lkml.kernel.org/r/1317816084-18026-2-git-send-email-gleb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
>>             Signed-off-by: Ingo Molnar <mingo-X9Un+BFzKDI@public.gmane.org>
>>
>> The updated manpage text clarifies that the "exclude_host" and
>> "exclude_guest" perf_event_open() attr bits only apply in the 
>> context of a KVM environment and are currently x86 only.
>>
>> This is a resend of the patch; the previous time I sent it
>> (http://thread.gmane.org/gmane.linux.man/7500) it did not
>> receive any comments.
>>
>> Signed-off-by: Vince Weaver <vincent.weaver-e7X0jjDqjFGHXe+LvDLADg@public.gmane.org>
>>
>> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
>> index 39c8d8c..1ea56c9 100644
>> --- a/man2/perf_event_open.2
>> +++ b/man2/perf_event_open.2
>> @@ -1006,11 +1006,25 @@ struct sample_id {
>>  .TP
>>  .IR "exclude_host" " (since Linux 3.2)"
>>  .\" commit a240f76165e6255384d4bdb8139895fac7988799
>> -Do not measure time spent in VM host.
>> +When conducting measurements that include processes running
>> +VM instances (i.e. have executed a
>> +.I KVM_RUN
>> +.BR ioctl (2)
>> +) only measure events happening inside a guest instance.
>> +This is only meaningful outside the guests; this setting does
>> +not change counts gathered inside of a guest.
>> +Currently this functionality is x86 only.
>>  .TP
>>  .IR "exclude_guest" " (since Linux 3.2)"
>>  .\" commit a240f76165e6255384d4bdb8139895fac7988799
>> -Do not measure time spent in VM guest.
>> +When conducting measurements that include processes running
>> +VM instances (i.e. have executed a
>> +.I KVM_RUN
>> +.BR ioctl (2)
>> +) do not measure events happening inside guest instances.
>> +This is only meaningful outside the guests; this setting does
>> +not change counts gathered inside of a guest.
>> +Currently this functionality is x86 only.
>>  .TP
>>  .IR "exclude_callchain_kernel" " (since Linux 3.7)"
>>  .\" commit d077526485d5c9b12fe85d0b2b3b7041e6bc5f91
>>
> 
> 


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
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Re: [patch] perf_event_open.2: Exclude_host/exclude_guest clarification

[Joerg Roedel]

Sorry for the delay, I was (and still am) busy with house moving.

On Thu, Feb 26, 2015 at 08:50:51AM +0100, Michael Kerrisk (man-pages) wrote:
> On 02/17/2015 06:32 AM, Michael Kerrisk (man-pages) wrote:
> > Hi Joerg,
> > 
> > Would you be willing to review/comment on Vince's patch, please.

The updated description looks good to me.


Acked-by: Joerg Roedel <jroedel@suse.de>

[patch] perf_event_open.2 exclude_host/exclude_guest clarification

[Vince Weaver]

Hello

The PAPI developers recently ran into some issues with the various virtual 
machine related settings in the perf_event_open() system call.

What follows is what my proposed updated manpage sections look like; I'm 
hoping to get some sort of feedback about the correctness of these statements.


	exclude_hv
		If this bit is set, the count excludes events that happen in 
		the hypervisor.  This is mainly for PMUs that have 
		built-in hardware support for this feature (such as POWER;
		this setting is silently ignored on x86). 

...

	exclude_host (since Linux 3.2)
		When  conducting  measurements that include processes 
		running VM instances (i.e. have executed a KVM_RUN 
		ioctl(2) ) only  measure events happening inside a guest 
		instance.  This is only meaningful outside the guests; 
		this setting does not change counts gathered inside of a 
		guest.  Currently this functionality is x86 only.

	exclude_guest (since Linux 3.2)
		When conducting measurements that include processes 
		running VM instances  (i.e.  have executed a KVM_RUN 
		ioctl(2) ) do not measure events happening inside guest
		instances.  This is only meaningful outside the guests;  
		this setting does not change counts gathered inside of a 
		guest.  Currently this functionality is x86 only.



Signed-off-by: Vince Weaver <vincent.weaver-e7X0jjDqjFGHXe+LvDLADg@public.gmane.org>

diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
index 638124c..a413c13 100644
--- a/man2/perf_event_open.2
+++ b/man2/perf_event_open.2
@@ -833,10 +833,9 @@ If this bit is set, the count excludes events that happen in kernel-space.
 .IR "exclude_hv"
 If this bit is set, the count excludes events that happen in the
 hypervisor.
-This is mainly for PMUs that have built-in support for handling this
-(such as POWER).
-Extra support is needed for handling hypervisor measurements on most
-machines.
+This is mainly for PMUs that have built-in hardware support
+for this feature (such as POWER; this setting is silently
+ignored on x86).
 .TP
 .IR "exclude_idle"
 If set, don't count when the CPU is idle.
@@ -978,10 +977,24 @@ struct sample_id {
 .fi
 .TP
 .IR "exclude_host" " (since Linux 3.2)"
-Do not measure time spent in VM host.
+When conducting measurements that include processes running
+VM instances (i.e. have executed a
+.I KVM_RUN
+.BR ioctl (2)
+) only measure events happening inside a guest instance.
+This is only meaningful outside the guests; this setting does
+not change counts gathered inside of a guest.
+Currently this functionality is x86 only.
 .TP
 .IR "exclude_guest" " (since Linux 3.2)"
-Do not measure time spent in VM guest.
+When conducting measurements that include processes running
+VM instances (i.e. have executed a
+.I KVM_RUN
+.BR ioctl (2)
+) do not measure events happening inside guest instances.
+This is only meaningful outside the guests; this setting does
+not change counts gathered inside of a guest.
+Currently this functionality is x86 only.
 .TP
 .IR "exclude_callchain_kernel" " (since Linux 3.7)"
 Do not include kernel callchains.
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Re: [patch] perf_event_open.2 exclude_host/exclude_guest clarification

[Michael Kerrisk (man-pages)]

Hi Vince et al,

On 12/05/2014 04:41 PM, Vince Weaver wrote:
> Hello
> 
> The PAPI developers recently ran into some issues with the various virtual 
> machine related settings in the perf_event_open() system call.
> 
> What follows is what my proposed updated manpage sections look like; I'm 
> hoping to get some sort of feedback about the correctness of these statements.

Vince, thanks for the proposed patches.

Does anyone have feedback about the correctness of Vince's proposed patches?

> 
> 	exclude_hv
> 		If this bit is set, the count excludes events that happen in 
> 		the hypervisor.  This is mainly for PMUs that have 
> 		built-in hardware support for this feature (such as POWER;
> 		this setting is silently ignored on x86). 
> 
> ...
> 
> 	exclude_host (since Linux 3.2)
> 		When  conducting  measurements that include processes 
> 		running VM instances (i.e. have executed a KVM_RUN 
> 		ioctl(2) ) only  measure events happening inside a guest 
> 		instance.  This is only meaningful outside the guests; 
> 		this setting does not change counts gathered inside of a 
> 		guest.  Currently this functionality is x86 only.
> 
> 	exclude_guest (since Linux 3.2)
> 		When conducting measurements that include processes 
> 		running VM instances  (i.e.  have executed a KVM_RUN 
> 		ioctl(2) ) do not measure events happening inside guest
> 		instances.  This is only meaningful outside the guests;  
> 		this setting does not change counts gathered inside of a 
> 		guest.  Currently this functionality is x86 only.
> 
> 
> 
> Signed-off-by: Vince Weaver <vincent.weaver-e7X0jjDqjFGHXe+LvDLADg@public.gmane.org>
> 
> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
> index 638124c..a413c13 100644
> --- a/man2/perf_event_open.2
> +++ b/man2/perf_event_open.2
> @@ -833,10 +833,9 @@ If this bit is set, the count excludes events that happen in kernel-space.
>  .IR "exclude_hv"
>  If this bit is set, the count excludes events that happen in the
>  hypervisor.
> -This is mainly for PMUs that have built-in support for handling this
> -(such as POWER).
> -Extra support is needed for handling hypervisor measurements on most
> -machines.
> +This is mainly for PMUs that have built-in hardware support
> +for this feature (such as POWER; this setting is silently
> +ignored on x86).
>  .TP
>  .IR "exclude_idle"
>  If set, don't count when the CPU is idle.
> @@ -978,10 +977,24 @@ struct sample_id {
>  .fi
>  .TP
>  .IR "exclude_host" " (since Linux 3.2)"
> -Do not measure time spent in VM host.
> +When conducting measurements that include processes running
> +VM instances (i.e. have executed a
> +.I KVM_RUN
> +.BR ioctl (2)
> +) only measure events happening inside a guest instance.
> +This is only meaningful outside the guests; this setting does
> +not change counts gathered inside of a guest.
> +Currently this functionality is x86 only.
>  .TP
>  .IR "exclude_guest" " (since Linux 3.2)"
> -Do not measure time spent in VM guest.
> +When conducting measurements that include processes running
> +VM instances (i.e. have executed a
> +.I KVM_RUN
> +.BR ioctl (2)
> +) do not measure events happening inside guest instances.
> +This is only meaningful outside the guests; this setting does
> +not change counts gathered inside of a guest.
> +Currently this functionality is x86 only.
>  .TP
>  .IR "exclude_callchain_kernel" " (since Linux 3.7)"
>  Do not include kernel callchains.

Thanks,

Michael


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
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