diff mbox series

[v2,01/10] perf: Fix wrong comment about default event_idx

Message ID 20230512085321.13259-2-alexghiti@rivosinc.com
State New
Headers
Series riscv: Allow userspace to directly access perf counters |

Commit Message

Alexandre Ghiti May 12, 2023, 8:53 a.m. UTC 
  event_idx default implementation returns 0, not idx + 1.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
 include/linux/perf_event.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Andrew Jones May 31, 2023, 1:54 p.m. UTC | #1 
On Fri, May 12, 2023 at 10:53:12AM +0200, Alexandre Ghiti wrote:
> event_idx default implementation returns 0, not idx + 1.

The comment was correct until commit c719f56092ad ("perf: Fix and clean
up initialization of pmu::event_idx"). I'm not sure that warrants a fixes
tag, but maybe a reference in the commit message.

> 
> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
> ---
>  include/linux/perf_event.h | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index d5628a7b5eaa..56fe43b20966 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -442,7 +442,8 @@ struct pmu {
>  
>  	/*
>  	 * Will return the value for perf_event_mmap_page::index for this event,
> -	 * if no implementation is provided it will default to: event->hw.idx + 1.
> +	 * if no implementation is provided it will default to 0 (see
> +	 * perf_event_idx_default).
>  	 */
>  	int (*event_idx)		(struct perf_event *event); /*optional */
>  
> -- 
> 2.37.2
>

Otherwise,

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Alexandre Ghiti June 15, 2023, 7:10 a.m. UTC | #2 
On 31/05/2023 15:54, Andrew Jones wrote:
> On Fri, May 12, 2023 at 10:53:12AM +0200, Alexandre Ghiti wrote:
>> event_idx default implementation returns 0, not idx + 1.
> The comment was correct until commit c719f56092ad ("perf: Fix and clean
> up initialization of pmu::event_idx"). I'm not sure that warrants a fixes
> tag, but maybe a reference in the commit message.


You're right, I'll add a reference, I don't think it deserves a 
backport, that's just a comment.


>> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
>> ---
>>   include/linux/perf_event.h | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
>> index d5628a7b5eaa..56fe43b20966 100644
>> --- a/include/linux/perf_event.h
>> +++ b/include/linux/perf_event.h
>> @@ -442,7 +442,8 @@ struct pmu {
>>   
>>   	/*
>>   	 * Will return the value for perf_event_mmap_page::index for this event,
>> -	 * if no implementation is provided it will default to: event->hw.idx + 1.
>> +	 * if no implementation is provided it will default to 0 (see
>> +	 * perf_event_idx_default).
>>   	 */
>>   	int (*event_idx)		(struct perf_event *event); /*optional */
>>   
>> -- 
>> 2.37.2
>>
> Otherwise,
>
> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>


Thanks!
Atish Patra June 15, 2023, 8:24 a.m. UTC | #3 
On Thu, Jun 15, 2023 at 12:10 AM Alexandre Ghiti <alex@ghiti.fr> wrote:
>
>
> On 31/05/2023 15:54, Andrew Jones wrote:
> > On Fri, May 12, 2023 at 10:53:12AM +0200, Alexandre Ghiti wrote:
> >> event_idx default implementation returns 0, not idx + 1.
> > The comment was correct until commit c719f56092ad ("perf: Fix and clean
> > up initialization of pmu::event_idx"). I'm not sure that warrants a fixes
> > tag, but maybe a reference in the commit message.
>
>
> You're right, I'll add a reference, I don't think it deserves a
> backport, that's just a comment.
>
>

With that done:

Reviewed-by: Atish Patra <atishp@rivosinc.com>

> >> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
> >> ---
> >>   include/linux/perf_event.h | 3 ++-
> >>   1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> >> index d5628a7b5eaa..56fe43b20966 100644
> >> --- a/include/linux/perf_event.h
> >> +++ b/include/linux/perf_event.h
> >> @@ -442,7 +442,8 @@ struct pmu {
> >>
> >>      /*
> >>       * Will return the value for perf_event_mmap_page::index for this event,
> >> -     * if no implementation is provided it will default to: event->hw.idx + 1.
> >> +     * if no implementation is provided it will default to 0 (see
> >> +     * perf_event_idx_default).
> >>       */
> >>      int (*event_idx)                (struct perf_event *event); /*optional */
> >>
> >> --
> >> 2.37.2
> >>
> > Otherwise,
> >
> > Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
>
>
> Thanks!
>
diff mbox series

Patch

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index d5628a7b5eaa..56fe43b20966 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -442,7 +442,8 @@  struct pmu {
 
 	/*
 	 * Will return the value for perf_event_mmap_page::index for this event,
-	 * if no implementation is provided it will default to: event->hw.idx + 1.
+	 * if no implementation is provided it will default to 0 (see
+	 * perf_event_idx_default).
 	 */
 	int (*event_idx)		(struct perf_event *event); /*optional */