[Darwin] Use vm_kernel_page_size for WTF::pageSize().

<https://webkit.org/b/154726>

Reviewed by Antti Koivisto.

Source/WebKit2:

Use WTF::pageSize() for the SharedMemory page size.

* Platform/mac/SharedMemoryMac.cpp:
(WebKit::SharedMemory::systemPageSize):

Source/WTF:

Make sure we use the right VM page size on Darwin systems.
On devices where the native page size is 4 KB, it's both
possible and profitable to madvise in smaller chunks.

* wtf/PageBlock.cpp:
(WTF::systemPageSize):


Canonical link: https://commits.webkit.org/172815@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@197168 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WTF/ChangeLog

@@ -1,3 +1,17 @@
+2016-02-26  Andreas Kling  <akling@apple.com>
+
+        [Darwin] Use vm_kernel_page_size for WTF::pageSize().
+        <https://webkit.org/b/154726>
+
+        Reviewed by Antti Koivisto.
+
+        Make sure we use the right VM page size on Darwin systems.
+        On devices where the native page size is 4 KB, it's both
+        possible and profitable to madvise in smaller chunks.
+
+        * wtf/PageBlock.cpp:
+        (WTF::systemPageSize):
+
 2016-02-25  Gavin Barraclough  <barraclough@apple.com>
 
         Replace RefCounter::Token implementation with RefPtr

Source/WTF/wtf/PageBlock.cpp

@@ -26,6 +26,10 @@
 #include "config.h"
 #include "PageBlock.h"
 
+#if OS(DARWIN)
+#include <mach/vm_page_size.h>
+#endif
+
 #if OS(UNIX)
 #include <unistd.h>
 #endif
@@ -40,7 +44,14 @@ namespace WTF {
 static size_t s_pageSize;
 static size_t s_pageMask;
 
-#if OS(UNIX)
+#if OS(DARWIN)
+
+inline size_t systemPageSize()
+{
+    return vm_kernel_page_size;
+}
+
+#elif OS(UNIX)
 
 inline size_t systemPageSize()
 {

Source/WebKit2/ChangeLog

@@ -1,3 +1,15 @@
+2016-02-26  Andreas Kling  <akling@apple.com>
+
+        [Darwin] Use vm_kernel_page_size for WTF::pageSize().
+        <https://webkit.org/b/154726>
+
+        Reviewed by Antti Koivisto.
+
+        Use WTF::pageSize() for the SharedMemory page size.
+
+        * Platform/mac/SharedMemoryMac.cpp:
+        (WebKit::SharedMemory::systemPageSize):
+
 2016-02-25  Ryuan Choi  <ryuan.choi@navercorp.com>
 
         [EFL] Remove WebUIPopupMenuClient

Source/WebKit2/Platform/mac/SharedMemoryMac.cpp

@@ -35,6 +35,7 @@
 #include <mach/mach_error.h>
 #include <mach/mach_port.h>
 #include <mach/vm_map.h>
+#include <wtf/PageBlock.h>
 #include <wtf/RefPtr.h>
 
 namespace WebKit {
@@ -217,7 +218,7 @@ bool SharedMemory::createHandle(Handle& handle, Protection protection)
 
 unsigned SharedMemory::systemPageSize()
 {
-    return vm_page_size;
+    return WTF::pageSize();
 }
 
 WebCore::MachSendRight SharedMemory::createSendRight(Protection protection) const