diff -up webkitgtk-2.8.0/Source/JavaScriptCore/heap/CopiedBlock.h.page_size_align webkitgtk-2.8.0/Source/JavaScriptCore/heap/CopiedBlock.h

--- webkitgtk-2.8.0/Source/JavaScriptCore/heap/CopiedBlock.h.page_size_align	2015-03-23 09:08:04.000000000 +0100

+++ webkitgtk-2.8.0/Source/JavaScriptCore/heap/CopiedBlock.h	2015-04-08 12:02:51.218138924 +0200

@@ -79,7 +79,7 @@ public:

     size_t size();

     size_t capacity();

-    static const size_t blockSize = 32 * KB;

+    static const size_t blockSize = 64 * KB;

     bool hasWorkList();

     CopyWorkList& workList();

diff -up webkitgtk-2.8.0/Source/JavaScriptCore/interpreter/JSStack.cpp.page_size_align webkitgtk-2.8.0/Source/JavaScriptCore/interpreter/JSStack.cpp

--- webkitgtk-2.8.0/Source/JavaScriptCore/interpreter/JSStack.cpp.page_size_align	2015-04-08 12:02:51.218138924 +0200

+++ webkitgtk-2.8.0/Source/JavaScriptCore/interpreter/JSStack.cpp	2015-04-08 12:04:48.158143620 +0200

@@ -58,7 +58,8 @@ JSStack::JSStack(VM& vm)

     size_t capacity = Options::maxPerThreadStackUsage();

     ASSERT(capacity && isPageAligned(capacity));

-    m_reservation = PageReservation::reserve(WTF::roundUpToMultipleOf(commitSize, capacity), OSAllocator::JSVMStackPages);

+    size_t commitsize = pageSize();

+    m_reservation = PageReservation::reserve(WTF::roundUpToMultipleOf(commitsize, capacity), OSAllocator::JSVMStackPages);

     setStackLimit(highAddress());

     m_commitTop = highAddress();

@@ -92,7 +93,8 @@ bool JSStack::growSlowCase(Register* new

     // have it is still within our budget. If not, we'll fail to grow and

     // return false.

     ptrdiff_t delta = reinterpret_cast<char*>(m_commitTop) - reinterpret_cast<char*>(newTopOfStackWithReservedZone);

-    delta = WTF::roundUpToMultipleOf(commitSize, delta);

+    size_t commitsize = pageSize();

+    delta = WTF::roundUpToMultipleOf(commitsize, delta);

     Register* newCommitTop = m_commitTop - (delta / sizeof(Register));

     if (newCommitTop < reservationTop())

         return false;