From 48636dcac28524a61fab44896fb9bf01f4fbf8b8 Mon Sep 17 00:00:00 2001
From: Yury Semikhatsky <yurys@chromium.org>
Date: Wed, 28 Oct 2026 10:42:26 -0700
Subject: [PATCH] devops: run Windows CI tests at normal I/O priority

The Windows runner starts steps at I/O priority Low. The driver and the
browsers inherit it, and Firefox storage flushes stall until tests time out.
Reset the test steps to Normal, as microsoft/playwright#43707 does upstream.
---
 .github/workflows/test.yml    | 12 +++++++---
 scripts/windows-normal-io.ps1 | 44 +++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 3 deletions(-)
 create mode 100644 scripts/windows-normal-io.ps1

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 2d750a7cf..74bb73e1b 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -34,11 +34,15 @@ jobs:
     - name: Install browsers
       run: mvn exec:java -e -D exec.mainClass=com.microsoft.playwright.CLI -D exec.args="install --with-deps" -f playwright/pom.xml --no-transfer-progress
     - name: Run tests
-      run: ${{ runner.os == 'Linux' && 'xvfb-run --auto-servernum --server-args="-screen 0 1280x960x24"' || '' }} mvn test --no-transfer-progress --fail-at-end ${{ runner.os == 'Windows' && '-D junit.parallel.factor=0.25' || '' }} -D org.slf4j.simpleLogger.showDateTime=true -D org.slf4j.simpleLogger.dateTimeFormat=HH:mm:ss
+      run: |
+        ${{ runner.os == 'Windows' && '. ./scripts/windows-normal-io.ps1' || '' }}
+        ${{ runner.os == 'Linux' && 'xvfb-run --auto-servernum --server-args="-screen 0 1280x960x24"' || '' }} mvn test --no-transfer-progress --fail-at-end ${{ runner.os == 'Windows' && '-D junit.parallel.factor=0.25' || '' }} -D org.slf4j.simpleLogger.showDateTime=true -D org.slf4j.simpleLogger.dateTimeFormat=HH:mm:ss
       env:
         BROWSER: ${{ matrix.browser }}
     - name: Run tracing tests w/ sources
-      run: ${{ runner.os == 'Linux' && 'xvfb-run --auto-servernum --server-args="-screen 0 1280x960x24"' || '' }} mvn test --no-transfer-progress --fail-at-end --projects=playwright -D test=*TestTracing* -D org.slf4j.simpleLogger.showDateTime=true -D org.slf4j.simpleLogger.dateTimeFormat=HH:mm:ss
+      run: |
+        ${{ runner.os == 'Windows' && '. ./scripts/windows-normal-io.ps1' || '' }}
+        ${{ runner.os == 'Linux' && 'xvfb-run --auto-servernum --server-args="-screen 0 1280x960x24"' || '' }} mvn test --no-transfer-progress --fail-at-end --projects=playwright -D test=*TestTracing* -D org.slf4j.simpleLogger.showDateTime=true -D org.slf4j.simpleLogger.dateTimeFormat=HH:mm:ss
       env:
         BROWSER: ${{ matrix.browser }}
         PLAYWRIGHT_JAVA_SRC: src/test/java
@@ -81,7 +85,9 @@ jobs:
       - name: Install browsers
         run: mvn exec:java -e -D exec.mainClass=com.microsoft.playwright.CLI -D exec.args="install --with-deps" -f playwright/pom.xml --no-transfer-progress
       - name: Run tests
-        run: ${{ runner.os == 'Linux' && 'xvfb-run --auto-servernum --server-args="-screen 0 1280x960x24"' || '' }} mvn test --no-transfer-progress --fail-at-end ${{ runner.os == 'Windows' && '-D junit.parallel.factor=0.25' || '' }} -D org.slf4j.simpleLogger.showDateTime=true -D org.slf4j.simpleLogger.dateTimeFormat=HH:mm:ss
+        run: |
+          ${{ runner.os == 'Windows' && '. ./scripts/windows-normal-io.ps1' || '' }}
+          ${{ runner.os == 'Linux' && 'xvfb-run --auto-servernum --server-args="-screen 0 1280x960x24"' || '' }} mvn test --no-transfer-progress --fail-at-end ${{ runner.os == 'Windows' && '-D junit.parallel.factor=0.25' || '' }} -D org.slf4j.simpleLogger.showDateTime=true -D org.slf4j.simpleLogger.dateTimeFormat=HH:mm:ss
         env:
           BROWSER: chromium
           BROWSER_CHANNEL: ${{ matrix.browser-channel }}
diff --git a/scripts/windows-normal-io.ps1 b/scripts/windows-normal-io.ps1
new file mode 100644
index 000000000..f1308b638
--- /dev/null
+++ b/scripts/windows-normal-io.ps1
@@ -0,0 +1,44 @@
+# Dot-source at the start of a Windows test step: the self-hosted runner starts steps at
+# I/O priority Low, which the driver and the browsers inherit, and Firefox storage flushes
+# then stall until tests time out. See https://github.com/microsoft/playwright/issues/43704.
+
+$ErrorActionPreference = 'Stop'
+
+Add-Type -TypeDefinition @'
+using System;
+using System.Runtime.InteropServices;
+
+public static class TestProcessIOPriority {
+    [DllImport("ntdll.dll")]
+    public static extern int NtSetInformationProcess(
+        IntPtr process, int informationClass, ref int information, int size);
+
+    [DllImport("ntdll.dll")]
+    public static extern int NtQueryInformationProcess(
+        IntPtr process, int informationClass, out int information, int size, out int length);
+}
+'@
+
+$priority = 0
+$length = 0
+$status = [TestProcessIOPriority]::NtQueryInformationProcess(
+    [IntPtr](-1), 33, [ref]$priority, 4, [ref]$length)
+if ($status -ne 0) {
+    throw ('Reading I/O priority failed: NTSTATUS 0x{0:X8}' -f $status)
+}
+$inheritedPriority = $priority
+$priority = 2
+$status = [TestProcessIOPriority]::NtSetInformationProcess(
+    [IntPtr](-1), 33, [ref]$priority, 4)
+if ($status -ne 0) {
+    throw ('Setting normal I/O priority failed: NTSTATUS 0x{0:X8}' -f $status)
+}
+$status = [TestProcessIOPriority]::NtQueryInformationProcess(
+    [IntPtr](-1), 33, [ref]$priority, 4, [ref]$length)
+if ($status -ne 0) {
+    throw ('Reading I/O priority failed: NTSTATUS 0x{0:X8}' -f $status)
+}
+if ($priority -ne 2) {
+    throw "Expected normal I/O priority (2), got $priority"
+}
+Write-Host "Test launcher I/O priority: $inheritedPriority -> $priority (Normal)"