Author: [email protected]
Date: Mon May 25 09:33:00 2009
New Revision: 2045
Modified:
branches/bleeding_edge/src/heap.cc
branches/bleeding_edge/src/heap.h
branches/bleeding_edge/src/spaces.cc
Log:
- Introduce histograms collecting data about the number of set remembered
set
bits in a page.
Review URL: http://codereview.chromium.org/113819
Modified: branches/bleeding_edge/src/heap.cc
==============================================================================
--- branches/bleeding_edge/src/heap.cc (original)
+++ branches/bleeding_edge/src/heap.cc Mon May 25 09:33:00 2009
@@ -2664,12 +2664,13 @@
#endif // DEBUG
-void Heap::IterateRSetRange(Address object_start,
- Address object_end,
- Address rset_start,
- ObjectSlotCallback copy_object_func) {
+int Heap::IterateRSetRange(Address object_start,
+ Address object_end,
+ Address rset_start,
+ ObjectSlotCallback copy_object_func) {
Address object_address = object_start;
Address rset_address = rset_start;
+ int set_bits_count = 0;
// Loop over all the pointers in [object_start, object_end).
while (object_address < object_end) {
@@ -2686,6 +2687,7 @@
// If this pointer does not need to be remembered anymore, clear
// the remembered set bit.
if (!Heap::InNewSpace(*object_p)) result_rset &= ~bitmask;
+ set_bits_count++;
}
object_address += kPointerSize;
}
@@ -2699,6 +2701,7 @@
}
rset_address += kIntSize;
}
+ return set_bits_count;
}
@@ -2706,11 +2709,20 @@
ASSERT(Page::is_rset_in_use());
ASSERT(space == old_pointer_space_ || space == map_space_);
+ static void* paged_rset_histogram = StatsTable::CreateHistogram(
+ "V8.RSetPaged",
+ 0,
+ Page::kObjectAreaSize / kPointerSize,
+ 30);
+
PageIterator it(space, PageIterator::PAGES_IN_USE);
while (it.has_next()) {
Page* page = it.next();
- IterateRSetRange(page->ObjectAreaStart(), page->AllocationTop(),
- page->RSetStart(), copy_object_func);
+ int count = IterateRSetRange(page->ObjectAreaStart(),
page->AllocationTop(),
+ page->RSetStart(), copy_object_func);
+ if (paged_rset_histogram != NULL) {
+ StatsTable::AddHistogramSample(paged_rset_histogram, count);
+ }
}
}
Modified: branches/bleeding_edge/src/heap.h
==============================================================================
--- branches/bleeding_edge/src/heap.h (original)
+++ branches/bleeding_edge/src/heap.h Mon May 25 09:33:00 2009
@@ -667,10 +667,11 @@
// Iterates a range of remembered set addresses starting with rset_start
// corresponding to the range of allocated pointers
// [object_start, object_end).
- static void IterateRSetRange(Address object_start,
- Address object_end,
- Address rset_start,
- ObjectSlotCallback copy_object_func);
+ // Returns the number of bits that were set.
+ static int IterateRSetRange(Address object_start,
+ Address object_end,
+ Address rset_start,
+ ObjectSlotCallback copy_object_func);
// Returns whether the object resides in new space.
static inline bool InNewSpace(Object* object);
Modified: branches/bleeding_edge/src/spaces.cc
==============================================================================
--- branches/bleeding_edge/src/spaces.cc (original)
+++ branches/bleeding_edge/src/spaces.cc Mon May 25 09:33:00 2009
@@ -2423,6 +2423,13 @@
void LargeObjectSpace::IterateRSet(ObjectSlotCallback copy_object_func) {
ASSERT(Page::is_rset_in_use());
+ static void* lo_rset_histogram = StatsTable::CreateHistogram(
+ "V8.RSetLO",
+ 0,
+ // Keeping this histogram's buckets the same as the paged space
histogram.
+ Page::kObjectAreaSize / kPointerSize,
+ 30);
+
LargeObjectIterator it(this);
while (it.has_next()) {
// We only have code, sequential strings, or fixed arrays in large
@@ -2433,15 +2440,18 @@
// Iterate the normal page remembered set range.
Page* page = Page::FromAddress(object->address());
Address object_end = object->address() + object->Size();
- Heap::IterateRSetRange(page->ObjectAreaStart(),
- Min(page->ObjectAreaEnd(), object_end),
- page->RSetStart(),
- copy_object_func);
+ int count = Heap::IterateRSetRange(page->ObjectAreaStart(),
+ Min(page->ObjectAreaEnd(),
object_end),
+ page->RSetStart(),
+ copy_object_func);
// Iterate the extra array elements.
if (object_end > page->ObjectAreaEnd()) {
- Heap::IterateRSetRange(page->ObjectAreaEnd(), object_end,
- object_end, copy_object_func);
+ count += Heap::IterateRSetRange(page->ObjectAreaEnd(), object_end,
+ object_end, copy_object_func);
+ }
+ if (lo_rset_histogram != NULL) {
+ StatsTable::AddHistogramSample(lo_rset_histogram, count);
}
}
}
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