Re: [PATCH] perf/x86/intel: Use rdmsrl_safe when initializing RAPL PMU.

Stephane Eranian
2014-04-23T15:44:33Z

On Wed, Apr 23, 2014 at 5:35 PM, Borislav Petkov <bp@alien8.de> wrote:
> On Wed, Apr 23, 2014 at 05:18:29PM +0200, Stephane Eranian wrote:
>> On Wed, Apr 23, 2014 at 5:16 PM, Borislav Petkov <bp@alien8.de> wrote:
>> > On Wed, Apr 23, 2014 at 05:14:33PM +0200, Stephane Eranian wrote:
>> >> Wouldn't rdmsrl_safe() return 0 on success?
>> >
>> > Yes.
>> >
>> then the if() test is wrong:
>> if (!rdmsrl_safe())
>> return -1;
>>
>> Should be:
>> if (rdmsrl_safe())
>> return -1;
>>
>> Or am I missing something?
>
> Yeah, that is wrong:
>
> if (!rdmsrl_safe(MSR_RAPL_POWER_UNIT, &msr_rapl_power_unit_bits))
> return -1;
>
> On error we return -EIO, on success 0. Just remove the "!".
>
Yeah, will post a patch ASAP. A comment describing return values
where rdmsrl_safe() is defined would maybe help avoid problems in the future.
Thanks.

>
> --
> Regards/Gruss,
> Boris.
>
> Sent from a fat crate under my desk. Formatting is fine.
> --