Mesa (master): intel/perf: fix raw query kernel metric selection

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Module: Mesa
Branch: master
Commit: ec1fa1d51ff614c19d08c949482b40c060de48c9
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=ec1fa1d51ff614c19d08c949482b40c060de48c9

Author: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
Date:   Mon Aug 24 13:52:59 2020 +0300

intel/perf: fix raw query kernel metric selection

The raw query is meant to be used with MDAPI [1]. When using this
metric without this library, we usually selected the TestOa metric to
provide some default sensible values (instead of undefined).
Historically this TestOa metric lived in the kernel at ID=1. We
removed all metrics from the kernel in kernel commit 9aba9c188da136
("drm/i915/perf: remove generated code").

This fixes the Mesa code to use a valid metric set ID (1 could work
some of the time, but not guaranteed).

[1] : https://github.com/intel/metrics-discovery

v2: Store fallback metric at init time

v3: Drop TestOa lookout

v4: Skip the existing queries (Marcin)

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
CC: <mesa-stable at lists.freedesktop.org>
Tested-by: Marcin Ślusarz <marcin.slusarz at intel.com> (v1)
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6438>

---

 src/intel/perf/gen_perf.c       | 13 +++++++++++++
 src/intel/perf/gen_perf.h       |  5 +++++
 src/intel/perf/gen_perf_query.c |  2 +-
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/intel/perf/gen_perf.c b/src/intel/perf/gen_perf.c
index ba1b4f8b127..d9f20501512 100644
--- a/src/intel/perf/gen_perf.c
+++ b/src/intel/perf/gen_perf.c
@@ -770,6 +770,19 @@ load_oa_metrics(struct gen_perf_config *perf, int fd,
    /* sort counters in each individual group created by this function by name */
    for (int i = existing_queries; i < perf->n_queries; ++i)
       sort_query(&perf->queries[i]);
+
+   /* Select a fallback OA metric. Look for the TestOa metric or use the last
+    * one if no present (on HSW).
+    */
+   for (int i = existing_queries; i < perf->n_queries; i++) {
+      if (perf->queries[i].symbol_name &&
+          strcmp(perf->queries[i].symbol_name, "TestOa") == 0) {
+         perf->fallback_raw_oa_metric = perf->queries[i].oa_metrics_set_id;
+         break;
+      }
+   }
+   if (perf->fallback_raw_oa_metric == 0)
+      perf->fallback_raw_oa_metric = perf->queries[perf->n_queries - 1].oa_metrics_set_id;
 }
 
 struct gen_perf_registers *
diff --git a/src/intel/perf/gen_perf.h b/src/intel/perf/gen_perf.h
index 073236c4317..790719ccbad 100644
--- a/src/intel/perf/gen_perf.h
+++ b/src/intel/perf/gen_perf.h
@@ -283,6 +283,11 @@ struct gen_perf_config {
     */
    struct hash_table *oa_metrics_table;
 
+   /* When MDAPI hasn't configured the metric we need to use by the time the
+    * query begins, this OA metric is used as a fallback.
+    */
+   uint64_t fallback_raw_oa_metric;
+
    /* Whether we have support for this platform. If true && n_queries == 0,
     * this means we will not be able to use i915-perf because of it is in
     * paranoid mode.
diff --git a/src/intel/perf/gen_perf_query.c b/src/intel/perf/gen_perf_query.c
index 7bd8e0277d2..593ab5c473b 100644
--- a/src/intel/perf/gen_perf_query.c
+++ b/src/intel/perf/gen_perf_query.c
@@ -423,7 +423,7 @@ get_metric_id(struct gen_perf_config *perf,
    if (!gen_perf_load_metric_id(perf, query->guid,
                                 &raw_query->oa_metrics_set_id)) {
       DBG("Unable to read query guid=%s ID, falling back to test config\n", query->guid);
-      raw_query->oa_metrics_set_id = 1ULL;
+      raw_query->oa_metrics_set_id = perf->fallback_raw_oa_metric;
    } else {
       DBG("Raw query '%s'guid=%s loaded ID: %"PRIu64"\n",
           query->name, query->guid, query->oa_metrics_set_id);