On 03/04/18 19:20, Kenneth Graunke wrote:
diff --git a/src/mesa/drivers/dri/i965/brw_performance_query.c
b/src/mesa/drivers/dri/i965/brw_performance_query.c
index 98666759d75..7d5b44cf61d 100644
--- a/src/mesa/drivers/dri/i965/brw_performance_query.c
+++ b/src/mesa/drivers/dri/i965/brw_performance_query.c
@@ -227,6 +227,8 @@ brw_perf_query(struct gl_perf_query_object *o)
#define MI_RPC_BO_SIZE 4096
#define MI_RPC_BO_END_OFFSET_BYTES (MI_RPC_BO_SIZE / 2)
+#define MI_FREQ_START_OFFSET_BYTES (3072)
+#define MI_FREQ_END_OFFSET_BYTES (3076)
Why these?
That's where I store the RPSTAT copy (before/after the workload).
Yeah, but I mean...why 3072? Is it some arbtirary number?
Hmm.... I don't remember exactly how I arrived to that number :)
I'll use something more sensible (like BO_SIZE - 4).
/******************************************************************************/
@@ -1150,6 +1152,9 @@ brw_begin_perf_query(struct gl_context *ctx,
/* Take a starting OA counter snapshot. */
brw->vtbl.emit_mi_report_perf_count(brw, obj->oa.bo, 0,
obj->oa.begin_report_id);
+ brw_store_register_mem32(brw, obj->oa.bo, GEN6_RPSTAT1,
+ MI_FREQ_START_OFFSET_BYTES);
+
++brw->perfquery.n_active_oa_queries;
/* No already-buffered samples can possibly be associated with this query
@@ -1233,6 +1238,8 @@ brw_end_perf_query(struct gl_context *ctx,
*/
if (!obj->oa.results_accumulated) {
/* Take an ending OA counter snapshot. */
+ brw_store_register_mem32(brw, obj->oa.bo, GEN6_RPSTAT1,
+ MI_FREQ_END_OFFSET_BYTES);
brw->vtbl.emit_mi_report_perf_count(brw, obj->oa.bo,
MI_RPC_BO_END_OFFSET_BYTES,
obj->oa.begin_report_id + 1);
@@ -1333,6 +1340,43 @@ brw_is_perf_query_ready(struct gl_context *ctx,
return false;
}
+static void
+read_gt_frequency(struct brw_context *brw,
+ struct brw_perf_query_object *obj)
+{
+ const struct gen_device_info *devinfo = &brw->screen->devinfo;
+ uint32_t *start_reg = obj->oa.map + MI_FREQ_START_OFFSET_BYTES,
+ *end_reg = obj->oa.map + MI_FREQ_END_OFFSET_BYTES;
+
+ switch (devinfo->gen) {
+ case 7:
+ case 8:
+ obj->oa.gt_frequency[0] =
+ ((start_reg[0] & GEN6_RPSTAT1_CURR_GT_FREQ_MASK) >>
+ GEN6_RPSTAT1_CURR_GT_FREQ_SHIFT) * 50ULL;
You can just do:
GET_FIELD(start_reg[0], GEN6_RPSTAT1_CURR_GT_FREQ)
instead of shifting and masking.
I think your conversions may be wrong. In particular, you don't handle
Gen9LP and Gen9 differently, while in the kernel, GT_PM_INTERVAL_TO_US
does:
Gen9 LP: 0.833 -> usec
Gen9+ non-LP: 1.33 -> usec
other: 1.28 -> usec
#define INTERVAL_1_28_TO_US(interval) (((interval) << 7) / 100)
#define INTERVAL_1_33_TO_US(interval) (((interval) << 2) / 3)
#define INTERVAL_0_833_TO_US(interval) (((interval) * 5) / 6)
#define GT_PM_INTERVAL_TO_US(dev_priv, interval) (INTEL_GEN(dev_priv) >= 9 ? \
(IS_GEN9_LP(dev_priv) ? \
INTERVAL_0_833_TO_US(interval) : \
INTERVAL_1_33_TO_US(interval)) : \
INTERVAL_1_28_TO_US(interval))
I could be mistaken, though.
Actually the kernel reads rpstat1 already and computes the frequency value.
I think the current code is equivalent to what the kernel does on big
cores & small cores >= gen9.
So...we need to multiply by 50, but don't need to convert to usec?
Otherwise I'm struggling to see how this is equivalent.
I think we read a number in frequency, not time interval :
https://cgit.freedesktop.org/drm-tip/tree/drivers/gpu/drm/i915/i915_debugfs.c#n1157
https://cgit.freedesktop.org/drm-tip/tree/drivers/gpu/drm/i915/intel_pm.c#n9395
On cherryview/valleyview, we need to read another register to figure out
the multipliers...
So I'll just leave it out for those small cores gens for now.
That seems reasonable...
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