On 27/11/2020 10:36, Chris Wilson wrote:
Quoting Tvrtko Ursulin (2020-11-27 10:01:09)
From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Adding any kinds of "last" abi markers is usually a mistake which I
repeated when implementing the PMU because it felt convenient at the time.
This patch marks I915_PMU_LAST as deprecated and stops the internal
implementation using it for sizing the event status bitmask and array.
New way of sizing the fields is a bit less elegant, but it omits reserving
slots for tracking events we are not interested in, and as such saves some
runtime space. Adding sampling events is likely to be a special event and
the new plumbing needed will be easily detected in testing. Existing
asserts against the bitfield and array sizes are keeping the code safe.
First event which gets the new treatment in this new scheme are the
interrupts - which neither needs any tracking in i915 pmu nor needs
waking up the GPU to read it.
v2:
* Streamline helper names. (Chris)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_pmu.c | 80 ++++++++++++++++++++++++---------
drivers/gpu/drm/i915/i915_pmu.h | 35 ++++++++++-----
include/uapi/drm/i915_drm.h | 2 +-
3 files changed, 83 insertions(+), 34 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
index cd786ad12be7..06dc63bf84d7 100644
--- a/drivers/gpu/drm/i915/i915_pmu.c
+++ b/drivers/gpu/drm/i915/i915_pmu.c
@@ -27,8 +27,6 @@
BIT(I915_SAMPLE_WAIT) | \
BIT(I915_SAMPLE_SEMA))
-#define ENGINE_SAMPLE_BITS (1 << I915_PMU_SAMPLE_BITS)
-
static cpumask_t i915_pmu_cpumask;
static unsigned int i915_pmu_target_cpu = -1;
@@ -57,17 +55,38 @@ static bool is_engine_config(u64 config)
return config < __I915_PMU_OTHER(0);
}
-static unsigned int config_enabled_bit(u64 config)
+static unsigned int other_bit(const u64 config)
+{
+ unsigned int val;
+
+ switch (config) {
+ case I915_PMU_ACTUAL_FREQUENCY:
+ val = __I915_PMU_ACTUAL_FREQUENCY_ENABLED;
+ break;
+ case I915_PMU_REQUESTED_FREQUENCY:
+ val = __I915_PMU_REQUESTED_FREQUENCY_ENABLED;
+ break;
+ case I915_PMU_RC6_RESIDENCY:
+ val = __I915_PMU_RC6_RESIDENCY_ENABLED;
+ break;
+ default:
Should we explicitly list the untracked events?
At least we should put a comment here to remind ourselves what takes
the default path.
/* Anything that doesn't require event tracking can be ignored */
Comment is I think enough, I wouldn't want to list all events because
that partially defeats the purpose of the simplification. If something
will be forgotten here IGTs would tell us.
+ return -1;
+ }
+
+ return I915_ENGINE_SAMPLE_COUNT + val;
+}
+
+static unsigned int config_bit(const u64 config)
{
if (is_engine_config(config))
return engine_config_sample(config);
else
- return ENGINE_SAMPLE_BITS + (config - __I915_PMU_OTHER(0));
+ return other_bit(config);
}
Thanks, that reads so much more clearly to me, and complements it use
well.
Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Thanks!
Regards,
Tvrtko
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
