Title: [170536] trunk/Source/WTF
- Revision
- 170536
- Author
- [email protected]
- Date
- 2014-06-27 11:06:41 -0700 (Fri, 27 Jun 2014)
Log Message
[ARMv7] Skip one particularly expensive fastFree() alignment check.
<https://webkit.org/b/134402>
The size class alignment check in fastFree() was crazy expensive on ARMv7
due to its use of modulo. Disabling it shaves 470ms off of PLT main thread
time in the web process.
Note that this was very hard to identify in profiles due to TCO.
Reviewed by Gavin Barraclough.
* wtf/FastMalloc.cpp:
(WTF::TCMalloc_ThreadCache::CreateCacheIfNecessary):
Modified Paths
Diff
Modified: trunk/Source/WTF/ChangeLog (170535 => 170536)
--- trunk/Source/WTF/ChangeLog 2014-06-27 17:50:36 UTC (rev 170535)
+++ trunk/Source/WTF/ChangeLog 2014-06-27 18:06:41 UTC (rev 170536)
@@ -1,3 +1,19 @@
+2014-06-27 Andreas Kling <[email protected]>
+
+ [ARMv7] Skip one particularly expensive fastFree() alignment check.
+ <https://webkit.org/b/134402>
+
+ The size class alignment check in fastFree() was crazy expensive on ARMv7
+ due to its use of modulo. Disabling it shaves 470ms off of PLT main thread
+ time in the web process.
+
+ Note that this was very hard to identify in profiles due to TCO.
+
+ Reviewed by Gavin Barraclough.
+
+ * wtf/FastMalloc.cpp:
+ (WTF::TCMalloc_ThreadCache::CreateCacheIfNecessary):
+
2014-06-26 Andreas Kling <[email protected]>
Bump FastMalloc thread cache max size to 1MB on iOS.
Modified: trunk/Source/WTF/wtf/FastMalloc.cpp (170535 => 170536)
--- trunk/Source/WTF/wtf/FastMalloc.cpp 2014-06-27 17:50:36 UTC (rev 170535)
+++ trunk/Source/WTF/wtf/FastMalloc.cpp 2014-06-27 18:06:41 UTC (rev 170536)
@@ -4168,7 +4168,9 @@
if (cl) {
size_t byteSizeForClass = ByteSizeForClass(cl);
+#if !(CPU(ARM_THUMB2) && !CPU(APPLE_ARMV7S))
RELEASE_ASSERT(!((reinterpret_cast<char*>(ptr) - reinterpret_cast<char*>(span->start << kPageShift)) % byteSizeForClass));
+#endif
pageheap->CacheSizeClass(p, cl);
#ifndef NO_TCMALLOC_SAMPLES
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