Bug 1751693: Add telemetry probe to measure glyph rasterization time and the required plumbing for WR. r=nical

Differential Revision: https://phabricator.services.mozilla.com/D140681

Cargo.lock

@@ -5814,9 +5814,11 @@ dependencies = [
  "dwrote",
  "etagere",
  "euclid",
+ "fog",
  "freetype",
  "fxhash",
  "gleam",
+ "glean",
  "glslopt",
  "lazy_static",
  "libc",

gfx/metrics.yaml

@@ -31,3 +31,20 @@ paint:
       - mwoodrow@mozilla.com
     expires: never
     telemetry_mirror: PAINT_BUILD_DISPLAYLIST_TIME
+
+wr:
+  rasterize_glyphs_time:
+    type: timing_distribution
+    description: >
+      The time to rasterize glyphs for consumption by WebRender.
+    time_unit: microsecond
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1728423
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1728423
+    data_sensitivity:
+      - technical
+    notification_emails:
+      - gfx-telemetry-alerts@mozilla.com
+    expires: never
+    telemetry_mirror: WR_RASTERIZE_GLYPHS_TIME

gfx/wr/webrender/Cargo.toml

@@ -18,7 +18,7 @@ display_list_stats = ["api/display_list_stats"]
 serialize_program = ["serde", "webrender_build/serialize_program"]
 no_static_freetype = []
 leak_checks = []
-gecko = []
+gecko = ["fog"]
 sw_compositor = ["swgl"]
 
 [build-dependencies]
@@ -51,6 +51,8 @@ svg_fmt = "0.4"
 tracy-rs = "0.1.2"
 derive_more = "0.99"
 etagere = "0.2.6"
+glean = "44.0.0"
+fog = { path = "../../../toolkit/components/glean/api", optional = true }
 swgl = { path = "../swgl", optional = true }
 
 [dev-dependencies]

gfx/wr/webrender/src/glyph_rasterizer/mod.rs

@@ -20,6 +20,7 @@ use crate::resource_cache::CachedImageData;
 use crate::texture_cache::{TextureCache, TextureCacheHandle, Eviction, TargetShader};
 use crate::gpu_cache::GpuCache;
 use crate::profiler::{self, TransactionProfile};
+use crate::telemetry::Telemetry;
 use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
 use rayon::ThreadPool;
 use rayon::prelude::*;
@@ -227,6 +228,7 @@ impl GlyphRasterizer {
         profile: &mut TransactionProfile,
     ) {
         profile.start_time(profiler::GLYPH_RESOLVE_TIME);
+        let timer_id = Telemetry::start_rasterize_glyphs_time();
 
         // Work around the borrow checker, since we call flush_glyph_requests below
         let mut pending_glyph_requests = mem::replace(
@@ -314,6 +316,7 @@ impl GlyphRasterizer {
         // we can schedule removing the fonts if needed.
         self.remove_dead_fonts();
 
+        Telemetry::stop_and_accumulate_rasterize_glyphs_time(timer_id);
         profile.end_time(profiler::GLYPH_RESOLVE_TIME);
     }
 }

gfx/wr/webrender/src/lib.rs

@@ -74,6 +74,7 @@ extern crate svg_fmt;
 
 #[macro_use]
 mod profiler;
+mod telemetry;
 
 mod batch;
 mod border;

gfx/wr/webrender/src/telemetry.rs

@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use glean::TimerId;
+#[cfg(feature = "gecko")]
+use fog::metrics::wr;
+
+pub struct Telemetry;
+
+/// Defines the interface for hooking up an external telemetry reporter to WR.
+#[cfg(not(feature = "gecko"))]
+impl Telemetry {
+    // Start rasterize glyph time collection
+    pub fn start_rasterize_glyphs_time() -> TimerId { return 0; }
+    // End rasterize glyph time collection
+    pub fn stop_and_accumulate_rasterize_glyphs_time(_id: TimerId) { }
+}
+
+#[cfg(feature = "gecko")]
+impl Telemetry {
+    pub fn start_rasterize_glyphs_time() -> TimerId { wr::rasterize_glyphs_time.start() }
+    pub fn stop_and_accumulate_rasterize_glyphs_time(id: TimerId) { wr::rasterize_glyphs_time.stop_and_accumulate(id); }
+}

toolkit/components/telemetry/Histograms.json

@@ -15999,16 +15999,27 @@
     "description": "WebRender scene swap time in miliseconds"
   },
   "WR_FRAMEBUILD_TIME": {
-    "record_in_processes": ["main", "gpu"],
-    "products": ["firefox", "fennec", "geckoview_streaming"],
-    "alert_emails": ["gfx-telemetry-alerts@mozilla.com", "jmuizelaar@mozilla.com"],
-    "bug_numbers": [1470901, 1584109],
+    "record_in_processes": [ "main", "gpu" ],
+    "products": [ "firefox", "fennec", "geckoview_streaming" ],
+    "alert_emails": [ "gfx-telemetry-alerts@mozilla.com", "jmuizelaar@mozilla.com" ],
+    "bug_numbers": [ 1470901, 1584109 ],
     "expires_in_version": "never",
     "kind": "exponential",
     "high": 1000,
     "n_buckets": 50,
     "description": "WebRender render time in milliseconds"
   },
+  "WR_RASTERIZE_GLYPHS_TIME": {
+    "record_in_processes": ["main", "gpu"],
+    "products": ["firefox", "fennec", "geckoview_streaming"],
+    "alert_emails": ["gfx-telemetry-alerts@mozilla.com", "jmuizelaar@mozilla.com"],
+    "bug_numbers": [ ],
+    "expires_in_version": "never",
+    "kind": "exponential",
+    "high": 500,
+    "n_buckets": 50,
+    "description": "Time taken by WebRender to rasterize a set of glyphs"
+  },
   "WEB_AUDIO_BECOMES_AUDIBLE_TIME": {
     "record_in_processes": ["content"],
     "products": ["firefox"],