Modified: trunk/Source/_javascript_Core/ChangeLog (87156 => 87157)
--- trunk/Source/_javascript_Core/ChangeLog 2011-05-24 15:49:28 UTC (rev 87156)
+++ trunk/Source/_javascript_Core/ChangeLog 2011-05-24 16:06:18 UTC (rev 87157)
@@ -1,3 +1,26 @@
+2011-05-23 Michael Saboff <msab...@apple.com>
+
+ Reviewed by Mark Rowe.
+
+ Safari often freezes when clicking "Return free memory" in Caches dialog
+ https://bugs.webkit.org/show_bug.cgi?id=61325
+
+ There are two fixes and improvement in instrumentation code used to find
+ one of the problems.
+ Changed ReleaseFreeList() to set the "decommitted" bit when releasing
+ pages to the system and moving Spans from the normal list to the returned
+ list.
+ Added a "not making forward progress" check to TCMalloc_PageHeap::scavenge
+ to eliminate an infinite loop if we can't meet the pagesToRelease target.
+ Added a check for the decommitted bit being set properly in
+ TCMalloc_PageHeap::CheckList.
+
+ * wtf/FastMalloc.cpp:
+ (WTF::TCMalloc_PageHeap::scavenge):
+ (WTF::TCMalloc_PageHeap::Check):
+ (WTF::TCMalloc_PageHeap::CheckList):
+ (WTF::ReleaseFreeList):
+
2011-05-23 Gavin Barraclough <barraclo...@apple.com>
Reviewed by Geoff Garen.
Modified: trunk/Source/_javascript_Core/wtf/FastMalloc.cpp (87156 => 87157)
--- trunk/Source/_javascript_Core/wtf/FastMalloc.cpp 2011-05-24 15:49:28 UTC (rev 87156)
+++ trunk/Source/_javascript_Core/wtf/FastMalloc.cpp 2011-05-24 16:06:18 UTC (rev 87157)
@@ -1357,7 +1357,7 @@
}
bool Check();
- bool CheckList(Span* list, Length min_pages, Length max_pages);
+ bool CheckList(Span* list, Length min_pages, Length max_pages, bool decommitted);
// Release all pages on the free list for reuse by the OS:
void ReleaseFreePages();
@@ -1637,7 +1637,9 @@
size_t pagesToRelease = min_free_committed_pages_since_last_scavenge_ * kScavengePercentage;
size_t targetPageCount = std::max<size_t>(kMinimumFreeCommittedPageCount, free_committed_pages_ - pagesToRelease);
+ Length lastFreeCommittedPages = free_committed_pages_;
while (free_committed_pages_ > targetPageCount) {
+ ASSERT(Check());
for (int i = kMaxPages; i > 0 && free_committed_pages_ >= targetPageCount; i--) {
SpanList* slist = (static_cast<size_t>(i) == kMaxPages) ? &large_ : &free_[i];
// If the span size is bigger than kMinSpanListsWithSpans pages return all the spans in the list, else return all but 1 span.
@@ -1658,6 +1660,10 @@
DLL_Prepend(&slist->returned, s);
}
}
+
+ if (lastFreeCommittedPages == free_committed_pages_)
+ break;
+ lastFreeCommittedPages = free_committed_pages_;
}
min_free_committed_pages_since_last_scavenge_ = free_committed_pages_;
@@ -2113,27 +2119,28 @@
bool TCMalloc_PageHeap::Check() {
ASSERT(free_[0].normal.next == &free_[0].normal);
ASSERT(free_[0].returned.next == &free_[0].returned);
- CheckList(&large_.normal, kMaxPages, 1000000000);
- CheckList(&large_.returned, kMaxPages, 1000000000);
+ CheckList(&large_.normal, kMaxPages, 1000000000, false);
+ CheckList(&large_.returned, kMaxPages, 1000000000, true);
for (Length s = 1; s < kMaxPages; s++) {
- CheckList(&free_[s].normal, s, s);
- CheckList(&free_[s].returned, s, s);
+ CheckList(&free_[s].normal, s, s, false);
+ CheckList(&free_[s].returned, s, s, true);
}
return true;
}
#if ASSERT_DISABLED
-bool TCMalloc_PageHeap::CheckList(Span*, Length, Length) {
+bool TCMalloc_PageHeap::CheckList(Span*, Length, Length, bool) {
return true;
}
#else
-bool TCMalloc_PageHeap::CheckList(Span* list, Length min_pages, Length max_pages) {
+bool TCMalloc_PageHeap::CheckList(Span* list, Length min_pages, Length max_pages, bool decommitted) {
for (Span* s = list->next; s != list; s = s->next) {
CHECK_CONDITION(s->free);
CHECK_CONDITION(s->length >= min_pages);
CHECK_CONDITION(s->length <= max_pages);
CHECK_CONDITION(GetDescriptor(s->start) == s);
CHECK_CONDITION(GetDescriptor(s->start+s->length-1) == s);
+ CHECK_CONDITION(s->decommitted == decommitted);
}
return true;
}
@@ -2145,6 +2152,7 @@
while (!DLL_IsEmpty(list)) {
Span* s = list->prev;
DLL_Remove(s);
+ s->decommitted = true;
DLL_Prepend(returned, s);
TCMalloc_SystemRelease(reinterpret_cast<void*>(s->start << kPageShift),
static_cast<size_t>(s->length << kPageShift));
