[patch] perf_event_open.2: Exclude_hv clarification

[patch] perf_event_open.2: Exclude_hv clarification

[Vince Weaver]

This manpage patch relates to the exclude_hv bit added to the kernel
in the following commit:

    exclude_hv; Linux 2.6.31
        commit 0475f9ea8e2cc030298908949e0d5da9f2fc2cfe
        Author: Paul Mackerras <paulus-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>

            perf_counters: allow users to count user, kernel and/or hypervisor events

            Signed-off-by: Paul Mackerras <paulus-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>

The updated manpage text points out that the exclude_hv 
"exclude hypervisor" bit only applies on hardware that 
supports this  feature (such as PowerPC)
and is silently ignored on other platforms such as x86.

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..665aa31 100644
--- a/man2/perf_event_open.2
+++ b/man2/perf_event_open.2
@@ -856,10 +856,9 @@ 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.
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Re: [patch] perf_event_open.2: Exclude_hv clarification

[Michael Kerrisk (man-pages)]

Hi Paul Mackerass,

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

Cheers,

Michael

On 02/11/2015 08:04 PM, Vince Weaver wrote:
> 
> This manpage patch relates to the exclude_hv bit added to the kernel
> in the following commit:
> 
>     exclude_hv; Linux 2.6.31
>         commit 0475f9ea8e2cc030298908949e0d5da9f2fc2cfe
>         Author: Paul Mackerras <paulus-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>
> 
>             perf_counters: allow users to count user, kernel and/or hypervisor events
> 
>             Signed-off-by: Paul Mackerras <paulus-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>
> 
> The updated manpage text points out that the exclude_hv 
> "exclude hypervisor" bit only applies on hardware that 
> supports this  feature (such as PowerPC)
> and is silently ignored on other platforms such as x86.
> 
> 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..665aa31 100644
> --- a/man2/perf_event_open.2
> +++ b/man2/perf_event_open.2
> @@ -856,10 +856,9 @@ 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.
> 


-- 
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_hv clarification

[Michael Kerrisk (man-pages)]

Hello Paul,

Ping!

Cheers,

Michael


On 02/17/2015 06:32 AM, Michael Kerrisk (man-pages) wrote:
> Hi Paul Mackerass,
> 
> Would you be willing to review/comment on Vince's patch, please.
> 
> Cheers,
> 
> Michael
> 
> On 02/11/2015 08:04 PM, Vince Weaver wrote:
>>
>> This manpage patch relates to the exclude_hv bit added to the kernel
>> in the following commit:
>>
>>     exclude_hv; Linux 2.6.31
>>         commit 0475f9ea8e2cc030298908949e0d5da9f2fc2cfe
>>         Author: Paul Mackerras <paulus@samba.org>
>>
>>             perf_counters: allow users to count user, kernel and/or hypervisor events
>>
>>             Signed-off-by: Paul Mackerras <paulus@samba.org>
>>
>> The updated manpage text points out that the exclude_hv 
>> "exclude hypervisor" bit only applies on hardware that 
>> supports this  feature (such as PowerPC)
>> and is silently ignored on other platforms such as x86.
>>
>> 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@maine.edu>
>>
>> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
>> index 39c8d8c..665aa31 100644
>> --- a/man2/perf_event_open.2
>> +++ b/man2/perf_event_open.2
>> @@ -856,10 +856,9 @@ 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.
>>
> 
> 


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