perf(core): disable Rspack parallelCodeSplitting temporarily (#11178)

Co-authored-by: slorber <749374+slorber@users.noreply.github.com>

.gitignore

@@ -48,3 +48,6 @@ website/i18n/**/*
 
 website/rspack-tracing.json
 website/bundler-cpu-profile.json
+website/profile.json.gz
+
+

package.json

@@ -31,8 +31,9 @@
     "build:website:deployPreview": "yarn build:website:deployPreview:testWrap && yarn build:website:deployPreview:build",
     "build:website:fast": "yarn workspace website build:fast",
     "build:website:fast:rsdoctor": "yarn workspace website build:fast:rsdoctor",
-    "build:website:fast:profile": "yarn workspace website build:fast:profile",
     "build:website:en": "yarn workspace website build --locale en",
+    "profile:bundle:cpu": "yarn workspace website profile:bundle:cpu:profile",
+    "profile:bundle:samply": "yarn workspace website profile:bundle:samply",
     "clear:website": "yarn workspace website clear",
     "serve:website": "yarn workspace website serve",
     "serve:website:baseUrl": "serve website",

packages/docusaurus-utils/src/lastUpdateUtils.ts

@@ -71,7 +71,10 @@ export const LAST_UPDATE_FALLBACK: LastUpdateData = {
 export async function getLastUpdate(
   filePath: string,
 ): Promise<LastUpdateData | null> {
-  if (process.env.NODE_ENV !== 'production') {
+  if (
+    process.env.NODE_ENV !== 'production' ||
+    process.env.DOCUSAURUS_DISABLE_LAST_UPDATE === 'true'
+  ) {
     // Use fake data in dev/test for faster development.
     return LAST_UPDATE_FALLBACK;
   }

packages/docusaurus/src/webpack/base.ts

@@ -187,6 +187,10 @@ export async function createBaseConfig({
         // @ts-expect-error: Rspack-only, not available in Webpack typedefs
         incremental: !isProd && !process.env.DISABLE_RSPACK_INCREMENTAL,
 
+        // TODO re-enable later, there's an Rspack performance issue
+        //  see https://github.com/facebook/docusaurus/pull/11178
+        parallelCodeSplitting: false,
+
         ...PersistentCacheAttributes,
       };
     }
@@ -249,14 +253,14 @@ export async function createBaseConfig({
       modules: ['node_modules', path.join(siteDir, 'node_modules')],
     },
     optimization: {
-      // The optimizations.concatenateModules is expensive
+      // The optimization.concatenateModules is expensive
       // - On the server, it's not useful to run it at all
       // - On the client, it leads to a ~3% JS assets total size decrease
       //   Let's keep it by default, but large sites may prefer faster builds
       // See also https://github.com/facebook/docusaurus/pull/11176
       concatenateModules: !isServer,
 
-      // The optimizations.mergeDuplicateChunks is expensive
+      // The optimization.mergeDuplicateChunks is expensive
       // - On the server, it's not useful to run it at all
       // - On the client, we compared assets/js before/after and see 0 change
       //   `du -sk js-before js-after` => the JS assets have the exact same size

project-words.txt

@@ -266,6 +266,8 @@ Rspack
 rspack
 Rspress
 rtcts
+Samply
+samply
 saurus
 Scaleway
 Sebastien

website/package.json

@@ -23,7 +23,8 @@
     "build:blogOnly": "cross-env yarn build --config=docusaurus.config-blog-only.js",
     "build:fast": "cross-env BUILD_FAST=true yarn build --locale en",
     "build:fast:rsdoctor": "cross-env BUILD_FAST=true RSDOCTOR=true yarn build --locale en",
-    "build:fast:profile": "cross-env BUILD_FAST=true node --cpu-prof --cpu-prof-dir .cpu-prof ./node_modules/.bin/docusaurus build --locale en",
+    "profile:bundle:cpu": "DOCUSAURUS_EXIT_AFTER_BUNDLING=true node --cpu-prof --cpu-prof-dir .cpu-prof ./node_modules/.bin/docusaurus build --locale en",
+    "profile:bundle:samply": "./profileSamply.sh",
     "netlify:build:production": "yarn docusaurus write-translations && yarn netlify:crowdin:delay && yarn netlify:crowdin:uploadSources && yarn netlify:crowdin:downloadTranslations && yarn build",
     "netlify:build:branchDeploy": "yarn build",
     "netlify:build:deployPreview": "yarn build",

website/profileSamply.sh

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+
+echo "This Samply profiling script doesn't work when it's run with Yarn, but you can run it manually instead"
+
+samply record -- DOCUSAURUS_EXIT_AFTER_BUNDLING=true node --perf-prof --perf-basic-prof --interpreted-frames-native-stack ./node_modules/.bin/docusaurus build --locale en