[Feat] (Metrics, Config): make the boundary-counter summary cadence a knob, because the device harness never reaches the teardown dump

- MOBILEGL_PIPE_STATS_PERIOD (default 120, clamped to [1, 1000000]) sets the frames per
  summary line; Init() latches it and a zero falls back to the default
- the trace APK's replay never tears MobileGL down, so MOBILEGL_PIPE_STATS_FILE never
  fires on device and a fixture shorter than the period (create-indirect) reported nothing
- PipeStatsTest pins the latch and the zero fallback

MobileGL/Config.h

@@ -347,6 +347,11 @@ namespace MobileGL::MG_Config {
         // the server without shipping index bytes per draw. Over budget it degrades to
         // per-draw staging, counted separately in the stats.
         Uint32 PipeIndexMirrorMb = 64;
+        // MOBILEGL_PIPE_STATS_PERIOD: frames per boundary-counter summary line. 120 is the
+        // steady-state cadence; the device retrace harness never reaches the teardown dump
+        // and a trimmed fixture (create-indirect) is shorter than 120 frames, so a run that
+        // needs its numbers at all sets this low enough to land at least one window.
+        Uint32 PipeStatsPeriod = 120;
         // MOBILEGL_PIPE_STATS_FILE: where the boundary counters' teardown JSON dump goes.
         // Empty (the default) means no dump; the per-120-frame summary line still goes to
         // the log whenever PipeStats is on, so a device run needs no writable path.

MobileGL/ConfigLoader.cpp

@@ -252,6 +252,7 @@ namespace MobileGL::MG_ConfigLoader {
             QueryEnvQuirkOverride("MOBILEGL_PIPE_LEGACY_MEMOS") != MG_Config::QuirkOverride::ForceOff;
         features.PipeTexelRetainMb = QueryEnvUint32("MOBILEGL_PIPE_TEXEL_RETAIN_MB", 0, 0, 4096);
         features.PipeIndexMirrorMb = QueryEnvUint32("MOBILEGL_PIPE_INDEX_MIRROR_MB", 64, 0, 4096);
+        features.PipeStatsPeriod = QueryEnvUint32("MOBILEGL_PIPE_STATS_PERIOD", 120, 1, 1000000);
         QueryEnvVariable("MOBILEGL_PIPE_STATS_FILE", features.PipeStatsFile, "");
     }
 

MobileGL/MG_Test/Util/PipeStatsTest.cpp

@@ -12,6 +12,7 @@
 
 #include <gtest/gtest.h>
 
+#include <Config.h>
 #include <MG_Util/Metrics/PipeStats.h>
 
 #include <cstdio>
@@ -77,6 +78,21 @@ namespace {
         EXPECT_EQ(PS::FrameCount(), 1u);
     }
 
+    TEST_F(PipeStatsTest, InitLatchesTheSummaryPeriodFromTheConfigAndNeverKeepsZero) {
+        // The device retrace harness never reaches the teardown dump, so the summary
+        // cadence is the only way a short fixture yields numbers at all: it must follow
+        // MOBILEGL_PIPE_STATS_PERIOD, and a zero must fall back rather than divide.
+        const Uint32 saved = MobileGL::MG_Config::Features.PipeStatsPeriod;
+        MobileGL::MG_Config::Features.PipeStatsPeriod = 7;
+        PS::Init();
+        EXPECT_EQ(PS::SummaryFramePeriod(), 7u);
+        MobileGL::MG_Config::Features.PipeStatsPeriod = 0;
+        PS::Init();
+        EXPECT_EQ(PS::SummaryFramePeriod(), PS::kDefaultSummaryFramePeriod);
+        MobileGL::MG_Config::Features.PipeStatsPeriod = saved;
+        PS::Init();
+    }
+
     TEST_F(PipeStatsTest, GateHitsAndMissesAreSeparateCounters) {
         for (Uint32 i = 0; i < 5; ++i) {
             PS::CountGate(PS::Gate::MagmaPipelineMemo, /*hit=*/true);
@@ -262,10 +278,10 @@ namespace {
     // A summary is emitted every kSummaryFramePeriod presents. The period is a constant the
     // smoke check depends on, so a change to it has to break a test.
     TEST_F(PipeStatsTest, SummaryPeriodIsOneHundredAndTwentyFrames) {
-        EXPECT_EQ(PS::kSummaryFramePeriod, 120u);
-        for (Uint64 i = 0; i < PS::kSummaryFramePeriod; ++i) {
+        EXPECT_EQ(PS::SummaryFramePeriod(), 120u);
+        for (Uint64 i = 0; i < PS::SummaryFramePeriod(); ++i) {
             PS::OnPresent();
         }
-        EXPECT_EQ(PS::FrameCount(), PS::kSummaryFramePeriod);
+        EXPECT_EQ(PS::FrameCount(), PS::SummaryFramePeriod());
     }
 } // namespace

MobileGL/MG_Util/Metrics/PipeStats.cpp

@@ -130,6 +130,8 @@ namespace MobileGL::MG_Util::PipeStats {
         Uint64 g_windowBaseFrames = 0;
         Bool g_shutdownDone = false;
 
+        // Frames per summary line, latched by Init() from MOBILEGL_PIPE_STATS_PERIOD.
+        Uint64 g_summaryPeriod = kDefaultSummaryFramePeriod;
         inline void Bump(Counter& counter, Uint64 amount) {
             counter.fetch_add(amount, std::memory_order_relaxed);
         }
@@ -253,14 +255,19 @@ namespace MobileGL::MG_Util::PipeStats {
         ResetCounters();
         g_shutdownDone = false;
         g_pipeStatsEnabled = MG_Config::Features.PipeStats;
+        g_summaryPeriod = MG_Config::Features.PipeStatsPeriod == 0
+                              ? kDefaultSummaryFramePeriod
+                              : static_cast<Uint64>(MG_Config::Features.PipeStatsPeriod);
         if (g_pipeStatsEnabled) {
             MGLOG_I("MGPipe stats: counters ON (MOBILEGL_PIPE_STATS), summary every %llu frames%s%s",
-                    static_cast<unsigned long long>(kSummaryFramePeriod),
+                    static_cast<unsigned long long>(g_summaryPeriod),
                     MG_Config::Features.PipeStatsFile.empty() ? "" : ", JSON dump to ",
                     MG_Config::Features.PipeStatsFile.c_str());
         }
     }
 
+    Uint64 SummaryFramePeriod() { return g_summaryPeriod; }
+
     void Shutdown() {
         if (!g_pipeStatsEnabled || g_shutdownDone) {
             return;
@@ -336,7 +343,7 @@ namespace MobileGL::MG_Util::PipeStats {
 #endif
         }
         const Uint64 frames = g_frameCount.fetch_add(1, std::memory_order_relaxed) + 1;
-        if (frames % kSummaryFramePeriod == 0) {
+        if (frames % g_summaryPeriod == 0) {
             EmitSummaryLine();
         }
     }

MobileGL/MG_Util/Metrics/PipeStats.h

@@ -129,7 +129,10 @@ namespace MobileGL::MG_Util::PipeStats {
     inline constexpr Uint32 kPayloadHistogramBuckets = 24;
 
     // Frames between two summary lines when MOBILEGL_PIPE_STATS=1.
-    inline constexpr Uint64 kSummaryFramePeriod = 120;
+    inline constexpr Uint64 kDefaultSummaryFramePeriod = 120;
+    // The period Init() latched from MOBILEGL_PIPE_STATS_PERIOD (kDefaultSummaryFramePeriod
+    // when unset); never 0.
+    Uint64 SummaryFramePeriod();
 
     // The latch. Read directly by Enabled() so the off path is a global load and a
     // predicted branch - do not turn this into a function call.