[Intel-gfx] [PATCH] drm/i915/pmu: Do not use colon characters in PMU names

[Tvrtko Ursulin]

On 10/01/2020 11:21, Chris Wilson wrote:
> Quoting Tvrtko Ursulin (2020-01-10 11:11:26)
>> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>
>> We use PCI device path in the registered PMU name in order to distinguish
>> between multiple GPUs. But since tools/perf reserves a special meaning to
>> the colon character we need to transliterate them to something else. We
>> choose a dash.
>>
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>> Reported-by: Dmitry Rogozhkin <dmitry.v.rogozhkin at intel.com>
>> Fixes: 05488673a4d4 ("drm/i915/pmu: Support multiple GPUs")
>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
>> Cc: Andi Kleen <ak at linux.intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_pmu.c | 14 ++++++++++++--
>>   1 file changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
>> index f3ef6700a5f2..ecbd0e1f1a90 100644
>> --- a/drivers/gpu/drm/i915/i915_pmu.c
>> +++ b/drivers/gpu/drm/i915/i915_pmu.c
>> @@ -1117,12 +1117,22 @@ void i915_pmu_register(struct drm_i915_private *i915)
>>          hrtimer_init(&pmu->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
>>          pmu->timer.function = i915_sample;
>>   
>> -       if (!is_igp(i915))
>> +       if (!is_igp(i915)) {
>>                  pmu->name = kasprintf(GFP_KERNEL,
>>                                        "i915-%s",
>>                                        dev_name(i915->drm.dev));
>> -       else
>> +               if (pmu->name) {
> 
> /* tools/perf reserves colons as special. */
> strreplace(pmu->name, ':', '-');

I didn't know this exists, thanks.

> I worry because the err_idx pointed to the '-'. We may have to use _

What is err_idx? But yes.. it would had served me well to test before 
sending. :) I just find identifiers with a mix of underscores and dashes 
so visually unappealing. :(

Regards,

Tvrtko