On Wed, 24 May 2023 10:53:20 -0700, Tvrtko Ursulin wrote:
>
Hi Tvrtko,
> On 24/05/2023 18:38, Dixit, Ashutosh wrote:
> > On Wed, 24 May 2023 04:38:18 -0700, Tvrtko Ursulin wrote:
> >> On 23/05/2023 16:19, Ashutosh Dixit wrote:
> >>> No functional changes but we can remove some unsightly index computation
> >>> and read/write functions if we convert the PMU sample array from a
> >>> one-dimensional to a two-dimensional array.
> >>>
> >>> Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
> >>> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>
> >>> ---
> >>> drivers/gpu/drm/i915/i915_pmu.c | 60 ++++++++++-----------------------
> >>> drivers/gpu/drm/i915/i915_pmu.h | 2 +-
> >>> 2 files changed, 19 insertions(+), 43 deletions(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
> >>> index b47d890d4ada1..137e0df9573ee 100644
> >>> --- a/drivers/gpu/drm/i915/i915_pmu.c
> >>> +++ b/drivers/gpu/drm/i915/i915_pmu.c
> >>> @@ -195,33 +195,6 @@ static inline s64 ktime_since_raw(const ktime_t kt)
> >>> return ktime_to_ns(ktime_sub(ktime_get_raw(), kt));
> >>> }
> >>> -static unsigned int
> >>> -__sample_idx(struct i915_pmu *pmu, unsigned int gt_id, int sample)
> >>> -{
> >>> - unsigned int idx = gt_id * __I915_NUM_PMU_SAMPLERS + sample;
> >>> -
> >>> - GEM_BUG_ON(idx >= ARRAY_SIZE(pmu->sample));
> >>> -
> >>> - return idx;
> >>> -}
> >>> -
> >>> -static u64 read_sample(struct i915_pmu *pmu, unsigned int gt_id, int sample)
> >>> -{
> >>> - return pmu->sample[__sample_idx(pmu, gt_id, sample)].cur;
> >>> -}
> >>> -
> >>> -static void
> >>> -store_sample(struct i915_pmu *pmu, unsigned int gt_id, int sample, u64 val)
> >>> -{
> >>> - pmu->sample[__sample_idx(pmu, gt_id, sample)].cur = val;
> >>> -}
> >>> -
> >>> -static void
> >>> -add_sample_mult(struct i915_pmu *pmu, unsigned int gt_id, int sample, u32 val, u32 mul)
> >>> -{
> >>> - pmu->sample[__sample_idx(pmu, gt_id, sample)].cur += mul_u32_u32(val, mul);
> >>> -}
> >>
> >> IMO read and store helpers could have stayed and just changed the
> >> implementation. Like add_sample_mult which you just moved. I would have
> >> been a smaller patch. So dunno.. a bit of a reluctant r-b.
> >
> > Are you referring just to add_sample_mult or to all the other functions
> > too? add_sample_mult I moved it to where it was before bc4be0a38b63
>
> Read and store helpers.
>
> > ("drm/i915/pmu: Prepare for multi-tile non-engine counters"), could have
> > left it here I guess.
> >
> > The other read and store helpers are not needed with the 2-d array at all
> > since the compiler itself will do that, so I thought it was better to get
> > rid of them completely.
>
> Yes I get it, just that I didn't see the benefit of removing them.
>
> For example:
>
> - store_sample(pmu, gt_id, __I915_SAMPLE_RC6, val);
> + pmu->sample[gt_id][__I915_SAMPLE_RC6].cur = val;
>
> It's a meh for me. Either flavour looks fine to me so I would have erred on
> the side of keeping the patch small. If anything I probably slightly prefer
> that the struct pmu_sample implementation was able to be changed with less
> churn before. For example. But a very minor argument really.
OK, I finally understood and have made this change in Patch v2. Please take
a look.
>
> Or maybe next step is get rid of the struct i915_pmu_sample. It is a struct
> because originally previous value was tracked too. Then I removed that and
> it was easier to keep the struct. I guess it can go now and then the
> removal of helpers here will look somewhat nicer without the trailing .cur
> on every affected line.
I have left this as is for now in case the i915_pmu_sample need to be
expanded again. Should be ok with the read/store helpers.
>
> > Let me know if you want any changes, otherwise I will leave as is.
>
> You can leave it as is, I dont' mind much.
I went ahead and changed it anyway since you seemed to want it.
Thanks.
--
Ashutosh
>
> >> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
> >
> > Thanks for the review. Thanks Andrzej too :)
> > --
> > Ashutosh
> >
> >>> -
> >>> static u64 get_rc6(struct intel_gt *gt)
> >>> {
> >>> struct drm_i915_private *i915 = gt->i915;
> >>> @@ -240,7 +213,7 @@ static u64 get_rc6(struct intel_gt *gt)
> >>> spin_lock_irqsave(&pmu->lock, flags);
> >>> if (awake) {
> >>> - store_sample(pmu, gt_id, __I915_SAMPLE_RC6, val);
> >>> + pmu->sample[gt_id][__I915_SAMPLE_RC6].cur = val;
> >>> } else {
> >>> /*
> >>> * We think we are runtime suspended.
> >>> @@ -250,13 +223,13 @@ static u64 get_rc6(struct intel_gt *gt)
> >>> * counter value.
> >>> */
> >>> val = ktime_since_raw(pmu->sleep_last[gt_id]);
> >>> - val += read_sample(pmu, gt_id, __I915_SAMPLE_RC6);
> >>> + val += pmu->sample[gt_id][__I915_SAMPLE_RC6].cur;
> >>> }
> >>> - if (val < read_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED))
> >>> - val = read_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED);
> >>> + if (val < pmu->sample[gt_id][__I915_SAMPLE_RC6_LAST_REPORTED].cur)
> >>> + val = pmu->sample[gt_id][__I915_SAMPLE_RC6_LAST_REPORTED].cur;
> >>> else
> >>> - store_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED, val);
> >>> + pmu->sample[gt_id][__I915_SAMPLE_RC6_LAST_REPORTED].cur = val;
> >>> spin_unlock_irqrestore(&pmu->lock, flags);
> >>> @@ -275,9 +248,8 @@ static void init_rc6(struct i915_pmu *pmu)
> >>> with_intel_runtime_pm(gt->uncore->rpm, wakeref) {
> >>> u64 val = __get_rc6(gt);
> >>> - store_sample(pmu, i, __I915_SAMPLE_RC6, val);
> >>> - store_sample(pmu, i, __I915_SAMPLE_RC6_LAST_REPORTED,
> >>> - val);
> >>> + pmu->sample[i][__I915_SAMPLE_RC6].cur = val;
> >>> + pmu->sample[i][__I915_SAMPLE_RC6_LAST_REPORTED].cur = val;
> >>> pmu->sleep_last[i] = ktime_get_raw();
> >>> }
> >>> }
> >>> @@ -287,7 +259,7 @@ static void park_rc6(struct intel_gt *gt)
> >>> {
> >>> struct i915_pmu *pmu = >->i915->pmu;
> >>> - store_sample(pmu, gt->info.id, __I915_SAMPLE_RC6, __get_rc6(gt));
> >>> + pmu->sample[gt->info.id][__I915_SAMPLE_RC6].cur = __get_rc6(gt);
> >>> pmu->sleep_last[gt->info.id] = ktime_get_raw();
> >>> }
> >>> @@ -428,6 +400,12 @@ engines_sample(struct intel_gt *gt, unsigned int
> >>> period_ns)
> >>> }
> >>> }
> >>> +static void
> >>> +add_sample_mult(struct i915_pmu_sample *sample, u32 val, u32 mul)
> >>> +{
> >>> + sample->cur += mul_u32_u32(val, mul);
> >>> +}
> >>> +
> >>> static bool
> >>> frequency_sampling_enabled(struct i915_pmu *pmu, unsigned int gt)
> >>> {
> >>> @@ -467,12 +445,12 @@ frequency_sample(struct intel_gt *gt, unsigned int period_ns)
> >>> if (!val)
> >>> val = intel_gpu_freq(rps, rps->cur_freq);
> >>> - add_sample_mult(pmu, gt_id, __I915_SAMPLE_FREQ_ACT,
> >>> + add_sample_mult(&pmu->sample[gt_id][__I915_SAMPLE_FREQ_ACT],
> >>> val, period_ns / 1000);
> >>> }
> >>> if (pmu->enable &
> >>> config_mask(__I915_PMU_REQUESTED_FREQUENCY(gt_id))) {
> >>> - add_sample_mult(pmu, gt_id, __I915_SAMPLE_FREQ_REQ,
> >>> + add_sample_mult(&pmu->sample[gt_id][__I915_SAMPLE_FREQ_REQ],
> >>> intel_rps_get_requested_frequency(rps),
> >>> period_ns / 1000);
> >>> }
> >>> @@ -673,14 +651,12 @@ static u64 __i915_pmu_event_read(struct perf_event *event)
> >>> switch (config) {
> >>> case I915_PMU_ACTUAL_FREQUENCY:
> >>> val =
> >>> - div_u64(read_sample(pmu, gt_id,
> >>> - __I915_SAMPLE_FREQ_ACT),
> >>> + div_u64(pmu->sample[gt_id][__I915_SAMPLE_FREQ_ACT].cur,
> >>> USEC_PER_SEC /* to MHz */);
> >>> break;
> >>> case I915_PMU_REQUESTED_FREQUENCY:
> >>> val =
> >>> - div_u64(read_sample(pmu, gt_id,
> >>> - __I915_SAMPLE_FREQ_REQ),
> >>> + div_u64(pmu->sample[gt_id][__I915_SAMPLE_FREQ_REQ].cur,
> >>> USEC_PER_SEC /* to MHz */);
> >>> break;
> >>> case I915_PMU_INTERRUPTS:
> >>> diff --git a/drivers/gpu/drm/i915/i915_pmu.h b/drivers/gpu/drm/i915/i915_pmu.h
> >>> index 33d80fbaab8bc..d20592e7db999 100644
> >>> --- a/drivers/gpu/drm/i915/i915_pmu.h
> >>> +++ b/drivers/gpu/drm/i915/i915_pmu.h
> >>> @@ -127,7 +127,7 @@ struct i915_pmu {
> >>> * Only global counters are held here, while the per-engine ones are in
> >>> * struct intel_engine_cs.
> >>> */
> >>> - struct i915_pmu_sample sample[I915_PMU_MAX_GTS * __I915_NUM_PMU_SAMPLERS];
> >>> + struct i915_pmu_sample sample[I915_PMU_MAX_GTS][__I915_NUM_PMU_SAMPLERS];
> >>> /**
> >>> * @sleep_last: Last time GT parked for RC6 estimation.
> >>> */
