Changeset 244229 in webkit

Timestamp:

Apr 12, 2019 1:37:38 PM (5 years ago)

Author:

rniwa@webkit.org

Message:

WebThread should run at a higher priority than user initiated
​https://bugs.webkit.org/show_bug.cgi?id=196849
<rdar://problem/46851062>

Reviewed by Geoffrey Garen.

Use QOS_CLASS_USER_INTERACTIVE on WebThread with -10 relative priority so that WebThread
won't wait for other threads with priority 30-37 but does not content with the main thread.

Also removed the call to pthread_attr_setschedparam which disables QoS.

This improves the blocked time in StartWebThread from 2~3ms to 250μs while cold launching
iBooks to an opened book.

• platform/ios/wak/WebCoreThread.mm:

(StartWebThread): Replaced 200 * 4096 by 800 * KB for a better readability.

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/ios/wak/WebCoreThread.mm (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-04-11  Ryosuke Niwa  <rniwa@webkit.org>
+
+        WebThread should run at a higher priority than user initiated
+        https://bugs.webkit.org/show_bug.cgi?id=196849
+        <rdar://problem/46851062>
+
+        Reviewed by Geoffrey Garen.
+
+        Use QOS_CLASS_USER_INTERACTIVE on WebThread with -10 relative priority so that WebThread
+        won't wait for other threads with priority 30-37 but does not content with the main thread.
+
+        Also removed the call to pthread_attr_setschedparam which disables QoS.
+
+        This improves the blocked time in StartWebThread from 2~3ms to 250μs while cold launching
+        iBooks to an opened book.
+
+        * platform/ios/wak/WebCoreThread.mm:
+        (StartWebThread): Replaced 200 * 4096 by 800 * KB for a better readability.
+
 2019-04-12  Ryosuke Niwa  <rniwa@webkit.org>
 

trunk/Source/WebCore/platform/ios/wak/WebCoreThread.mm

@@ -668 +668 @@
     // a 512 kb stack, but we need more space in order to have room for the JavaScriptCore
     // reentrancy limit. This limit works on both the simulator and the device.
-    pthread_attr_setstacksize(&tattr, 200 * 4096);
-
-    struct sched_param param;
-    pthread_attr_getschedparam(&tattr, &param);
-    param.sched_priority--;
-    pthread_attr_setschedparam(&tattr, &param);
+    pthread_attr_setstacksize(&tattr, 800 * KB);
+
+    pthread_attr_set_qos_class_np(&tattr, QOS_CLASS_USER_INTERACTIVE, -10);
 
     // Wait for the web thread to startup completely before we continue.