Bug 1547018 - Add a mochitest tracking child process startup main thread I/O, r=Felipe.
☠☠ backed out by 5ea2c0493913 ☠ ☠
authorFlorian Quèze <florian@queze.net>
Tue, 07 May 2019 17:09:39 +0000
changeset 534819 5c597a3f82bdf9c52042be492539e8776218f445
parent 534818 eb8757f9586fbdbeef944c4dcfa55e505b739f4a
child 534820 72723e7257b1f9825a5f1a6478c0dbdea9202c97
push id2082
push userffxbld-merge
push dateMon, 01 Jul 2019 08:34:18 +0000
treeherdermozilla-release@2fb19d0466d2 [default view] [failures only]
perfherder[talos] [build metrics] [platform microbench] (compared to previous push)
reviewersFelipe
bugs1547018
milestone68.0a1
first release with
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
last release without
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
Bug 1547018 - Add a mochitest tracking child process startup main thread I/O, r=Felipe. Differential Revision: https://phabricator.services.mozilla.com/D28869
browser/base/content/test/performance/browser.ini
browser/base/content/test/performance/browser_startup_content_mainthreadio.js
--- a/browser/base/content/test/performance/browser.ini
+++ b/browser/base/content/test/performance/browser.ini
@@ -27,16 +27,17 @@ skip-if = !debug
 [browser_startup.js]
 [browser_startup_content.js]
 skip-if = !e10s
 [browser_startup_flicker.js]
 run-if = debug || devedition || nightly_build # Requires startupRecorder.js, which isn't shipped everywhere by default
 [browser_startup_hiddenwindow.js]
 skip-if = os == 'mac'
 [browser_startup_mainthreadio.js]
+[browser_startup_content_mainthreadio.js]
 [browser_tabclose_grow.js]
 [browser_tabclose.js]
 skip-if = (os == 'win') || (os == 'mac') # Bug 1488537, Bug 1531417, Bug 1497713
 [browser_tabdetach.js]
 [browser_tabopen.js]
 skip-if = (verify && (os == 'mac'))
 [browser_tabopen_squeeze.js]
 [browser_tabstrip_overflow_underflow.js]
copy from browser/base/content/test/performance/browser_startup_mainthreadio.js
copy to browser/base/content/test/performance/browser_startup_content_mainthreadio.js
--- a/browser/base/content/test/performance/browser_startup_mainthreadio.js
+++ b/browser/base/content/test/performance/browser_startup_content_mainthreadio.js
@@ -8,44 +8,35 @@
  *   ./mach test --appname=dist <path to test>
  *
  * If you made changes that cause this test to fail, it's likely because you
  * are touching more files or directories during startup.
  * Most code has no reason to use main thread I/O.
  * If for some reason accessing the file system on the main thread is currently
  * unavoidable, consider defering the I/O as long as you can, ideally after
  * the end of startup.
- * If your code isn't strictly required to show the first browser window,
- * it shouldn't be loaded before we are done with first paint.
- * Finally, if your code isn't really needed during startup, it should not be
- * loaded before we have started handling user events.
  */
 
 "use strict";
 
-const { AddonManager } = ChromeUtils.import("resource://gre/modules/AddonManager.jsm");
-
 /* Set this to true only for debugging purpose; it makes the output noisy. */
 const kDumpAllStacks = false;
 
 // Shortcuts for conditions.
 const LINUX = AppConstants.platform == "linux";
 const WIN = AppConstants.platform == "win";
 const MAC = AppConstants.platform == "macosx";
 
 /* Paths in the whitelist can:
  *  - be a full path, eg. "/etc/mime.types"
  *  - have a prefix which will be resolved using Services.dirsvc
  *    eg. "GreD:omni.ja"
  *    It's possible to have only a prefix, in thise case the directory will
  *    still be resolved, eg. "UAppData:"
  *  - use * at the begining and/or end as a wildcard
- *  - For Windows specific entries that require resolving the path to its
- *    canonical form, ie. the old DOS 8.3 format, use canonicalize: true.
- *    This is needed for stat calls to non-existent files.
  * The folder separator is '/' even for Windows paths, where it'll be
  * automatically converted to '\'.
  *
  * Specifying 'ignoreIfUnused: true' will make the test ignore unused entries;
  * without this the test is strict and will fail if a whitelist entry isn't used.
  *
  * Each entry specifies the maximum number of times an operation is expected to
  * occur.
@@ -65,648 +56,155 @@ const MAC = AppConstants.platform == "ma
  *   fsync: supported only on Windows.
  *
  * If an entry specifies more than one operation, if at least one of them is
  * encountered, the test won't report a failure for the entry. This helps when
  * whitelisting cases where the reported operations aren't the same on all
  * platforms due to the I/O interposer inconsistencies across platforms
  * documented above.
  */
-const startupPhases = {
-  // Anything done before or during app-startup must have a compelling reason
-  // to run before we have even selected the user profile.
-  "before profile selection": [
-    { // bug 1541226
-      path: "UAppData:",
-      condition: WIN,
-      stat: 3,
-    },
-    { // bug 1541200
-      path: "UAppData:Crash Reports/InstallTime20*",
-      stat: 1, // only caught on Windows.
-      read: 1,
-      write: 2,
-      close: 1,
-    },
-    { // bug 1541200
-      path: "UAppData:Crash Reports/LastCrash",
-      condition: WIN,
-      stat: 1, // only caught on Windows.
-      read: 1,
-    },
-    { // bug 1541200
-      path: "UAppData:Crash Reports/LastCrash",
-      condition: !WIN,
-      ignoreIfUnused: true, // only if we ever crashed on this machine
-      read: 1,
-      close: 1,
-    },
-    { // bug 1541226
-      path: "DefProfLRt.parent:",
-      condition: WIN,
-      stat: 1,
-    },
-    { // At least the read seems unavoidable for a regular startup.
-      path: "UAppData:profiles.ini",
-      condition: MAC,
-      stat: 1,
-      read: 1,
-      close: 1,
-    },
-    { // bug 1546931
-      path: "UAppData:installs.ini",
-      condition: WIN || MAC,
-      ignoreIfUnused: true, // only if a real profile exists on the system.
-      read: 1,
-      stat: 2,
-      close: 1,
-    },
-    { // At least the read seems unavoidable for a regular startup.
-      path: "UAppData:profiles.ini",
-      condition: WIN,
-      ignoreIfUnused: true, // only if a real profile exists on the system.
-      read: 1,
-      stat: 1,
-    },
-    { // bug 1541226, bug 1363586, bug 1541593
-      path: "ProfD:",
-      condition: WIN,
-      stat: 3,
-    },
-    {
-      path: "ProfLD:.startup-incomplete",
-      condition: !WIN, // Visible on Windows with an open marker
-      close: 1,
-    },
-    { // bug 1541491 to stop using this file, bug 1541494 to write correctly.
-      path: "ProfLD:compatibility.ini",
-      condition: !WIN, // Visible on Windows with an open marker
-      write: 18,
-      close: 1,
-    },
+const processes = {
+  "Web Content": [
     {
       path: "GreD:omni.ja",
       condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
     },
     { // bug 1376994
       path: "XCurProcD:omni.ja",
       condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
     },
-    {
-      path: "ProfD:parent.lock",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1541603
-      path: "ProfD:minidumps",
-      condition: WIN,
+    { // bug 1543761
+      path: "GreD:chrome.manifest",
+      condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
+      close: 1,
     },
-    { // bug 1543746
-      path: "XCurProcD:defaults/preferences",
-      condition: WIN,
+    { // bug 1376994, bug 1543761
+      path: "XCurProcD:chrome.manifest",
+      condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
+      close: 1,
     },
-    { // bug 1544034
-      path: "ProfLDS:startupCache/scriptCache-child-current.bin",
+    { // Exists call in ScopedXREEmbed::SetAppDir
+      path: "XCurProcD:",
       condition: WIN,
       stat: 1,
     },
-    { // bug 1544034
-      path: "ProfLDS:startupCache/scriptCache-child.bin",
-      condition: WIN,
+    { // bug 1357205
+      path: "XREAppFeat:webcompat@mozilla.org.xpi",
+      condition: !WIN,
       stat: 1,
     },
-    { // bug 1544034
-      path: "ProfLDS:startupCache/scriptCache-current.bin",
-      condition: WIN,
+    { // bug 1357205
+      path: "XREAppFeat:formautofill@mozilla.org.xpi",
+      condition: !WIN,
       stat: 1,
     },
-    { // bug 1544034
-      path: "ProfLDS:startupCache/scriptCache.bin",
-      condition: WIN,
+  ],
+  "Privileged Content": [
+    {
+      path: "GreD:omni.ja",
+      condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
     },
-    { // bug 1544037
-      path: "ProfLDS:startupCache/startupCache." +
-             (Services.appinfo.is64Bit ? 8 : 4) + ".little",
-      condition: WIN,
+    { // bug 1376994
+      path: "XCurProcD:omni.ja",
+      condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
     },
-    { // bug 1541601
-      path: "PrfDef:channel-prefs.js",
-      stat: 1,
-      read: 1,
-      close: 1,
-    },
     { // bug 1543761
       path: "GreD:chrome.manifest",
       condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
       close: 1,
     },
     { // bug 1376994, bug 1543761
       path: "XCurProcD:chrome.manifest",
       condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
       close: 1,
     },
-    { // At least the read seems unavoidable
-      path: "PrefD:prefs.js",
-      stat: 1,
-      read: 1,
-      close: 1,
-    },
-    { // bug 1543752
-      path: "PrefD:user.js",
-      stat: 1,
-      read: 1,
-      close: 1,
-    },
-    {
-      path: "*ld.so.conf*",
-      condition: LINUX,
-      read: 22,
-      close: 11,
-    },
-    { // bug 1546838
-      path: "ProfD:xulstore/data.mdb",
-      condition: WIN,
-      write: 1,
-      fsync: 1,
-    },
-  ],
-
-  "before opening first browser window": [
-    { // bug 1541226
-      path: "ProfD:",
-      condition: WIN,
-      stat: 2,
-    },
-    {
-      path: "XCurProcD:blocklist.xml",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1534745
-      path: "ProfD:cookies.sqlite-journal",
-      condition: !LINUX,
-      stat: 3,
-      write: 4,
-    },
-    { // bug 1534745
-      path: "ProfD:cookies.sqlite",
-      condition: !LINUX,
-      stat: 2,
-      read: 2,
-      write: 1,
-    },
-    { // bug 1534745
-      path: "ProfD:cookies.sqlite-wal",
-      condition: WIN,
-      stat: 2,
-    },
-    { // bug 975996
-      path: "ProfD:permissions.sqlite",
-      condition: WIN || MAC,
-      fsync: 7,
-      read: 2,
-      stat: 1,
-      write: 10,
-    },
-    { // bug 975996
-      path: "ProfD:permissions.sqlite-journal",
-      condition: WIN || MAC,
-      fsync: 7,
-      stat: 26,
-      write: 38,
-    },
-    { // bug 975996
-      path: "ProfD:permissions.sqlite-wal",
-      condition: WIN,
-      stat: 20,
-    },
-    { // Seems done by OS X and outside of our control.
-      path: "*.savedState/restorecount.plist",
-      condition: MAC,
-      ignoreIfUnused: true,
-      write: 1,
-    },
-    {
-      path: "*ld.so.conf*",
-      condition: LINUX,
-      read: 22,
-      close: 11,
-    },
-    { // bug 1545167
-      path: "/etc/mime.types",
-      condition: LINUX,
-      read: 3,
-      close: 3,
-    },
-    {
-      path: "UChrm:userChrome.css",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1541233
-      path: "UChrm:userContent.css",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1541246
-      path: "XREUSysExt:",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1541246
-      path: "XRESysExtDev:",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1541246
-      path: "ProfD:extensions",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1541246
-      path: "XCurProcD:extensions",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1541246
-      path: "UAppData:",
-      ignoreIfUnused: true, // sometimes before opening first browser window,
-                            // sometimes before first paint
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1546838
-      path: "ProfD:xulstore/data.mdb",
-      condition: WIN,
-      read: 1,
-    },
-  ],
-
-  // We reach this phase right after showing the first browser window.
-  // This means that any I/O at this point delayed first paint.
-  "before first paint": [
-    { // bug 1541226
-      path: "ProfD:",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1545119
-      path: "OldUpdRootD:",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1446012
-      path: "UpdRootD:updates/0/update.status",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1545123
-      path: "ProfD:pluginreg.dat",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1545123
-      path: "ProfD:pluginreg.dat.tmp",
-      stat: 1,
-      write: 64,
-      close: 1,
-    },
-    { // bug 1545123
-      path: "ProfD:plugins",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1545123
-      path: "APlugns:",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1545123
-      path: "UserPlugins.parent:",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1545123
-      path: "UserPlugins:",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1545123
-      path: "ProfD:plugins/nptest.dll",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1545123
-      path: "ProfD:plugins/npsecondtest.dll",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1545123
-      path: "ProfD:plugins/npthirdtest.dll",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1545123
-      path: "ProfD:plugins/npswftest.dll",
-      condition: WIN,
-      stat: 1,
-    },
-    {
-      path: "XREAppFeat:formautofill@mozilla.org.xpi",
-      condition: !WIN,
-      stat: 1,
-      close: 1,
-    },
-    { // bug 1545167
-      path: "/etc/mime.types",
-      condition: LINUX,
-      read: 1,
-      close: 1,
-    },
-    { // We only hit this for new profiles.
-      path: "XREAppDist:distribution.ini",
+    { // Exists call in ScopedXREEmbed::SetAppDir
+      path: "XCurProcD:",
       condition: WIN,
       stat: 1,
     },
-    {
-      path: "*WindowsApps/microsoft.windowscommunicationsapps*",
-      condition: WIN,
-      ignoreIfUnused: true,
-      stat: 3,
+    { // bug 1357205
+      path: "XREAppFeat:webcompat@mozilla.org.xpi",
+      condition: !WIN,
+      stat: 1,
     },
-    { // bug 1545139
-      path: "*Fonts/StaticCache.dat",
-      condition: WIN,
-      ignoreIfUnused: true, // Only on Win7
-      read: 1,
-    },
-    { // bug 1541246
-      path: "UAppData:",
-      ignoreIfUnused: true, // sometimes before opening first browser window,
-                            // sometimes before first paint
-      condition: WIN,
+  ],
+  "WebExtensions": [
+    {
+      path: "GreD:omni.ja",
+      condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
     },
-    { // Not in packaged builds; useful for artifact builds.
-      path: "GreD:ScalarArtifactDefinitions.json",
-      condition: WIN && !AppConstants.MOZILLA_OFFICIAL,
+    { // bug 1376994
+      path: "XCurProcD:omni.ja",
+      condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
     },
-    { // Not in packaged builds; useful for artifact builds.
-      path: "GreD:EventArtifactDefinitions.json",
-      condition: WIN && !AppConstants.MOZILLA_OFFICIAL,
+    { // bug 1543761
+      path: "GreD:chrome.manifest",
+      condition: !WIN, // Visible on Windows with an open marker
       stat: 1,
+      close: 1,
     },
-    { // bug 1546838
-      path: "ProfD:xulstore/data.mdb",
-      condition: MAC,
-      write: 3,
+    { // bug 1376994, bug 1543761
+      path: "XCurProcD:chrome.manifest",
+      condition: !WIN, // Visible on Windows with an open marker
+      stat: 1,
+      close: 1,
     },
-    { // bug 1543090
-      path: "GreD:omni.ja",
+    { // Exists call in ScopedXREEmbed::SetAppDir
+      path: "XCurProcD:",
       condition: WIN,
       stat: 1,
     },
-    { // bug 1543090
-      path: "XCurProcD:omni.ja",
-      condition: WIN,
-      stat: 2,
-    },
-  ],
-
-  // We are at this phase once we are ready to handle user events.
-  // Any IO at this phase or before gets in the way of the user
-  // interacting with the first browser window.
-  "before handling user events": [
-    {
-      path: "GreD:update.test",
-      ignoreIfUnused: true,
-      condition: LINUX,
-      close: 1,
-    },
-    { // bug 1370516 - NSS should be initialized off main thread.
-      path: "ProfD:cert9.db",
-      condition: WIN,
-      read: 2,
-      stat: 2,
-    },
-    { // bug 1370516 - NSS should be initialized off main thread.
-      path: "ProfD:cert9.db",
-      condition: WIN,
-      ignoreIfUnused: true, // if canonicalize(ProfD) == ProfD, we'll use the previous entry.
-      canonicalize: true,
-      stat: 2,
-    },
-    { // bug 1370516 - NSS should be initialized off main thread.
-      path: "ProfD:cert9.db-journal",
-      condition: WIN,
-      canonicalize: true,
-      stat: 2,
-    },
-    { // bug 1370516 - NSS should be initialized off main thread.
-      path: "ProfD:cert9.db-wal",
-      condition: WIN,
-      canonicalize: true,
-      stat: 2,
-    },
-    { // bug 1370516 - NSS should be initialized off main thread.
-      path: "ProfD:pkcs11.txt",
-      condition: WIN,
-      read: 2,
-    },
-    { // bug 1370516 - NSS should be initialized off main thread.
-      path: "ProfD:key4.db",
-      condition: WIN,
-      read: 2,
-      stat: 2,
-    },
-    { // bug 1370516 - NSS should be initialized off main thread.
-      path: "ProfD:key4.db",
-      condition: WIN,
-      ignoreIfUnused: true, // if canonicalize(ProfD) == ProfD, we'll use the previous entry.
-      canonicalize: true,
-      stat: 2,
-    },
-    { // bug 1370516 - NSS should be initialized off main thread.
-      path: "ProfD:key4.db-journal",
-      condition: WIN,
-      canonicalize: true,
-      stat: 5,
-    },
-    { // bug 1370516 - NSS should be initialized off main thread.
-      path: "ProfD:key4.db-wal",
-      condition: WIN,
-      canonicalize: true,
-      stat: 5,
-    },
-    {
-      path: "XREAppFeat:webcompat-reporter@mozilla.org.xpi",
+    { // bug 1357205
+      path: "XREAppFeat:webcompat@mozilla.org.xpi",
       condition: !WIN,
-      ignoreIfUnused: true,
-      stat: 1,
-      close: 1,
-    },
-    { // bug 1003968
-      path: "XREAppDist:searchplugins",
-      condition: WIN,
-      stat: 1,
-    },
-    {
-      path: "XCurProcD:extensions",
-      condition: WIN,
-      stat: 1,
-    },
-    { // bug 1543090
-      path: "GreD:omni.ja",
-      condition: WIN,
       stat: 1,
     },
-    { // bug 1543090
-      path: "XCurProcD:omni.ja",
-      condition: WIN,
-      stat: 2,
-    },
-  ],
-
-  // Things that are expected to be completely out of the startup path
-  // and loaded lazily when used for the first time by the user should
-  // be blacklisted here.
-  "before becoming idle": [
-    {
-      path: "XREAppFeat:screenshots@mozilla.org.xpi",
-      ignoreIfUnused: true,
-      close: 1,
-    },
-    {
-      path: "XREAppFeat:webcompat-reporter@mozilla.org.xpi",
-      ignoreIfUnused: true,
-      stat: 1,
-      close: 1,
-    },
-    { // bug 1391590
-      path: "ProfD:places.sqlite-journal",
-      ignoreIfUnused: true,
-      fsync: 1,
-      stat: 4,
-      write: 2,
-    },
-    { // bug 1391590
-      path: "ProfD:places.sqlite-wal",
-      ignoreIfUnused: true,
-      stat: 4,
-      fsync: 3,
-      write: 148,
-    },
-    { // bug 1391590
-      path: "ProfD:places.sqlite-shm",
-      condition: WIN,
-      ignoreIfUnused: true,
+    { // bug 1357205
+      path: "XREAppFeat:formautofill@mozilla.org.xpi",
+      condition: !WIN,
       stat: 1,
     },
-    { // bug 1391590
-      path: "ProfD:places.sqlite",
-      ignoreIfUnused: true,
-      fsync: 2,
-      read: 1,
-      stat: 3,
-      write: 1310,
-    },
-    { // bug 1391590
-      path: "ProfD:favicons.sqlite-journal",
-      ignoreIfUnused: true,
-      fsync: 2,
-      stat: 7,
-      write: 7,
-    },
-    { // bug 1391590
-      path: "ProfD:favicons.sqlite-wal",
-      ignoreIfUnused: true,
-      fsync: 2,
-      stat: 7,
-      write: 15,
-    },
-    { // bug 1391590
-      path: "ProfD:favicons.sqlite-shm",
-      condition: WIN,
-      ignoreIfUnused: true,
-      stat: 2,
-    },
-    { // bug 1391590
-      path: "ProfD:favicons.sqlite",
-      ignoreIfUnused: true,
-      fsync: 3,
-      read: 4,
-      stat: 4,
-      write: 1300,
-    },
-    {
-      path: "ProfD:key4.db-journal",
-      condition: WIN,
-      canonicalize: true,
-      stat: 2,
-    },
-    {
-      path: "ProfD:key4.db-wal",
-      condition: WIN,
-      canonicalize: true,
-      stat: 2,
-    },
-    {
-      path: "ProfD:",
-      condition: WIN,
-      ignoreIfUnused: true,
-      stat: 3,
-    },
-    { // bug 1543090
-      path: "XCurProcD:omni.ja",
-      condition: WIN,
-      stat: 7,
+    { // bug 1357205
+      path: "XREAppFeat:screenshots@mozilla.org.xpi",
+      condition: !WIN,
+      close: 1,
     },
   ],
 };
 
-for (let name of ["d3d11layers", "d3d9video", "glcontext", "d3d11video", "wmfvpxvideo"]) {
-  startupPhases["before first paint"].push({
-    path: `ProfD:${name}.guard`,
-    ignoreIfUnused: true,
-    stat: 1,
-  });
-}
-
-function expandWhitelistPath(path, canonicalize = false) {
+function expandWhitelistPath(path) {
   if (path.includes(":")) {
     let [prefix, suffix] = path.split(":");
     let [key, property] = prefix.split(".");
     let dir = Services.dirsvc.get(key, Ci.nsIFile);
     if (property) {
       dir = dir[property];
     }
 
-    if (canonicalize) {
-      path = dir.QueryInterface(Ci.nsILocalFileWin).canonicalPath;
-    } else {
-      // Resolve symLinks.
-      let dirPath = dir.path;
-      while (dir && !dir.isSymlink()) {
-        dir = dir.parent;
-      }
-      if (dir) {
-        dirPath = dirPath.replace(dir.path, dir.target);
-      }
+    // Resolve symLinks.
+    let dirPath = dir.path;
+    while (dir && !dir.isSymlink()) {
+      dir = dir.parent;
+    }
+    if (dir) {
+      dirPath = dirPath.replace(dir.path, dir.target);
+    }
 
-      path = dirPath;
-    }
+    path = dirPath;
 
     if (suffix) {
       path += "/" + suffix;
     }
   }
   if (AppConstants.platform == "win") {
     path = path.replace(/\//g, "\\");
   }
@@ -726,16 +224,43 @@ function getStackFromProfile(profile, st
     frame = profile.stringTable[frame[frameLocationCol]];
     if (frame != "js::RunScript" && !frame.startsWith("next (self-hosted:")) {
       result.push(frame);
     }
   }
   return result;
 }
 
+function getIOMarkersFromProfile(profile) {
+  const nameCol = profile.markers.schema.name;
+  const dataCol = profile.markers.schema.data;
+
+  let markers = [];
+  for (let m of profile.markers.data) {
+    let markerName = profile.stringTable[m[nameCol]];
+
+    if (markerName != "FileIO")
+      continue;
+
+    let markerData = m[dataCol];
+    if (markerData.source == "sqlite-mainthread") {
+      continue;
+    }
+
+    let samples = markerData.stack.samples;
+    let stack = samples.data[0][samples.schema.stack];
+    markers.push({operation: markerData.operation,
+                  filename: markerData.filename,
+                  source: markerData.source,
+                  stackId: stack});
+  }
+
+  return markers;
+}
+
 function pathMatches(path, filename) {
   path = path.toLowerCase();
   return path == filename || // Full match
     // Wildcard on both sides of the path
     (path.startsWith("*") && path.endsWith("*") &&
      filename.includes(path.slice(1, -1))) ||
     // Wildcard suffix
     (path.endsWith("*") && filename.startsWith(path.slice(0, -1))) ||
@@ -759,91 +284,55 @@ add_task(async function() {
                 "run 'mach package' and then use --appname=dist");
       return;
     }
   }
 
   let startupRecorder = Cc["@mozilla.org/test/startuprecorder;1"].getService().wrappedJSObject;
   await startupRecorder.done;
 
-  // Add system add-ons to the whitelist dynamically.
-  // They should go in the omni.ja file (bug 1357205).
-  {
-    let addons = await AddonManager.getAddonsByTypes(["extension"]);
-    for (let addon of addons) {
-      if (addon.isSystem) {
-        startupPhases["before opening first browser window"].push({
-          path: `XREAppFeat:${addon.id}.xpi`,
-          stat: 3,
-          close: 2,
-        });
-        startupPhases["before handling user events"].push({
-          path: `XREAppFeat:${addon.id}.xpi`,
-          condition: WIN,
-          stat: 2,
-        });
-      }
-    }
-  }
-
-  // Check for main thread I/O markers in the startup profile.
-  let profile = startupRecorder.data.profile.threads[0];
-
-  let phases = {};
-  {
-    const nameCol = profile.markers.schema.name;
-    const dataCol = profile.markers.schema.data;
-
-    let markersForCurrentPhase = [];
-
-    for (let m of profile.markers.data) {
-      let markerName = profile.stringTable[m[nameCol]];
-      if (markerName.startsWith("startupRecorder:")) {
-        phases[markerName.split("startupRecorder:")[1]] = markersForCurrentPhase;
-        markersForCurrentPhase = [];
-        continue;
-      }
-
-      if (markerName != "FileIO")
-        continue;
-
-      let markerData = m[dataCol];
-      if (markerData.source == "sqlite-mainthread") {
-        continue;
-      }
-
-      let samples = markerData.stack.samples;
-      let stack = samples.data[0][samples.schema.stack];
-      markersForCurrentPhase.push({operation: markerData.operation,
-                                   filename: markerData.filename,
-                                   source: markerData.source,
-                                   stackId: stack});
-    }
-  }
-
-  for (let phase in startupPhases) {
-    startupPhases[phase] =
-      startupPhases[phase].filter(entry => !("condition" in entry) || entry.condition);
-    startupPhases[phase].forEach(entry => {
+  for (let process in processes) {
+    processes[process] =
+      processes[process].filter(entry => !("condition" in entry) || entry.condition);
+    processes[process].forEach(entry => {
       entry.path = expandWhitelistPath(entry.path, entry.canonicalize);
     });
   }
 
   let tmpPath = expandWhitelistPath(MAC ? "TmpD:" : "/dev/shm").toLowerCase();
   let shouldPass = true;
-  for (let phase in phases) {
-    let whitelist = startupPhases[phase];
-    info(`whitelisted paths ${phase}:\n` +
+  for (let procName in processes) {
+    let whitelist = processes[procName];
+    info(`whitelisted paths for ${procName} process:\n` +
          whitelist.map(e => {
-           let operations = Object.keys(e).filter(k => k != "path")
+           let operations = Object.keys(e).filter(k => !["path", "condition"].includes(k))
                                   .map(k => `${k}: ${e[k]}`);
            return `  ${e.path} - ${operations.join(", ")}`;
          }).join("\n"));
 
-    let markers = phases[phase];
+    let profile;
+    for (let process of startupRecorder.data.profile.processes) {
+      if (process.threads[0].processName == procName) {
+        profile = process.threads[0];
+        break;
+      }
+    }
+    if (procName == "Privileged Content" && !profile) {
+      // The Privileged Content is started from an idle task that may not have
+      // been executed yet at the time we captured the startup profile in
+      // startupRecorder.
+      todo(false, `profile for ${procName} process not found`);
+    } else {
+      ok(profile, `Found profile for ${procName} process`);
+    }
+    if (!profile) {
+      continue;
+    }
+
+    let markers = getIOMarkersFromProfile(profile);
     for (let marker of markers) {
       if (marker.operation == "create/open") {
         // TODO: handle these I/O markers once they are supported on
         // non-Windows platforms.
         continue;
       }
 
       // Convert to lower case before comparing because the OS X test slaves
@@ -874,57 +363,57 @@ add_task(async function() {
           entry[marker.operation] = (entry[marker.operation] || 0) - 1;
           entry._used = true;
           expected = true;
           break;
         }
       }
       if (!expected) {
         record(false,
-               `unexpected ${marker.operation} on ${marker.filename} ${phase}`,
+               `unexpected ${marker.operation} on ${marker.filename} in ${procName} process`,
                undefined,
                "  " + getStackFromProfile(profile, marker.stackId).join("\n  "));
         shouldPass = false;
       }
       info(`(${marker.source}) ${marker.operation} - ${marker.filename}`);
       if (kDumpAllStacks) {
         info(getStackFromProfile(profile, marker.stackId).map(f => "  " + f)
                                                          .join("\n"));
       }
     }
 
     for (let entry of whitelist) {
       for (let op in entry) {
-        if (["path", "condition", "canonicalize", "ignoreIfUnused", "_used"].includes(op)) {
+        if (["path", "condition", "ignoreIfUnused", "_used"].includes(op)) {
           continue;
         }
         let message = `${op} on ${entry.path} `;
         if (entry[op] == 0) {
           message += "as many times as expected";
         } else if (entry[op] > 0) {
           message += `allowed ${entry[op]} more times`;
         } else {
           message += `${entry[op] * -1} more times than expected`;
         }
-        ok(entry[op] >= 0, `${message} ${phase}`);
+        ok(entry[op] >= 0, `${message} in ${procName} process`);
       }
       if (!("_used" in entry) && !entry.ignoreIfUnused) {
-        ok(false, `unused whitelist entry ${phase}: ${entry.path}`);
+        ok(false, `unused whitelist entry ${procName}: ${entry.path}`);
       }
     }
   }
 
   if (shouldPass) {
     ok(shouldPass, "No unexpected main thread I/O during startup");
   } else {
-    const filename = "startup-mainthreadio-profile.json";
+    const filename = "child-startup-mainthreadio-profile.json";
     let path = Cc["@mozilla.org/process/environment;1"]
                  .getService(Ci.nsIEnvironment)
                  .get("MOZ_UPLOAD_DIR");
     let encoder = new TextEncoder();
     let profilePath = OS.Path.join(path, filename);
     await OS.File.writeAtomic(profilePath,
                               encoder.encode(JSON.stringify(startupRecorder.data.profile)));
     ok(false,
-       "Found some unexpected main thread I/O during startup; profile uploaded in " +
-       filename);
+       "Found some unexpected main thread I/O during child process startup; " +
+       "profile uploaded in " + filename);
   }
 });