Changeset 289568 in webkit

Timestamp:

Feb 10, 2022, 12:27:45 PM (4 years ago)

Author:

Alan Coon

Message:

Cherry-pick r289145. rdar://problem/88366590

[libpas] Use os_unfair_lock instead of spinlock
​https://bugs.webkit.org/show_bug.cgi?id=236158

Reviewed by Geoffrey Garen.

os_unfair_lock is very fast while it can properly suspend threads.
A/B test result was neutral on Speedometer2 and JetStream2. So, to
reduce unnecessary CPU spins, let's replace spinlock with os_unfair_lock
if it is supported (if OS is Darwin).

• libpas/src/libpas/pas_config.h:

git-svn-id: ​https://svn.webkit.org/repository/webkit/trunk@289145 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Location:

branches/safari-613.1.16.0-branch/Source/bmalloc

Files:

• ChangeLog (modified) (1 diff)
• libpas/src/libpas/pas_config.h (modified) (1 diff)

branches/safari-613.1.16.0-branch/Source/bmalloc/ChangeLog

@@ +1 @@
+2022-02-10  Alan Coon  <alancoon@apple.com>
+
+        Cherry-pick r289145. rdar://problem/88366590
+
+    [libpas] Use os_unfair_lock instead of spinlock
+    https://bugs.webkit.org/show_bug.cgi?id=236158
+    
+    Reviewed by Geoffrey Garen.
+    
+    os_unfair_lock is very fast while it can properly suspend threads.
+    A/B test result was neutral on Speedometer2 and JetStream2. So, to
+    reduce unnecessary CPU spins, let's replace spinlock with os_unfair_lock
+    if it is supported (if OS is Darwin).
+    
+    * libpas/src/libpas/pas_config.h:
+    
+    git-svn-id: https://svn.webkit.org/repository/webkit/trunk@289145 268f45cc-cd09-0410-ab3c-d52691b4dbfc
+
+    2022-02-04  Yusuke Suzuki  <ysuzuki@apple.com>
+
+            [libpas] Use os_unfair_lock instead of spinlock
+            https://bugs.webkit.org/show_bug.cgi?id=236158
+
+            Reviewed by Geoffrey Garen.
+
+            os_unfair_lock is very fast while it can properly suspend threads.
+            A/B test result was neutral on Speedometer2 and JetStream2. So, to
+            reduce unnecessary CPU spins, let's replace spinlock with os_unfair_lock
+            if it is supported (if OS is Darwin).
+
+            * libpas/src/libpas/pas_config.h:
+
 2022-01-24  Alan Coon  <alancoon@apple.com>
 

branches/safari-613.1.16.0-branch/Source/bmalloc/libpas/src/libpas/pas_config.h

@@ -100 +100 @@
 #define PAS_ALLOCATOR_INDEX_BYTES        4
 
-#ifdef PAS_BMALLOC
+#if PAS_OS(DARWIN)
+#define PAS_USE_SPINLOCKS                0
+#else
 #define PAS_USE_SPINLOCKS                1
-#else
-#define PAS_USE_SPINLOCKS                0
 #endif