Profile FreeList

Profile FreeList

BUG=

[keishi, 2015-01-27 08:59:01]

GYP_DEFINES="gc_profile_marking=1 gc_profile_free_list=1"

https://codereview.chromium.org/717923005/diff/150001/Source/platform/heap/Th...
File Source/platform/heap/ThreadState.cpp (right):

https://codereview.chromium.org/717923005/diff/150001/Source/platform/heap/Th...
Source/platform/heap/ThreadState.cpp:624: void
ThreadState::snapshotFreeListIfNecessary()
Call when a snapshot could be recorded to the tracing json file.
Throttles to record only every 0.01 seconds.

https://codereview.chromium.org/717923005/diff/150001/Source/platform/heap/Th...
Source/platform/heap/ThreadState.cpp:638: void ThreadState::snapshotFreeList()
Records the stats from the heap.

https://codereview.chromium.org/717923005/diff/150001/Source/platform/heap/Th...
Source/platform/heap/ThreadState.cpp:1065: Heap::reportSweepingStats();
Report stats on the objects that will be sweeped.

https://codereview.chromium.org/717923005/diff/170001/Source/build/features.gypi
File Source/build/features.gypi (right):

https://codereview.chromium.org/717923005/diff/170001/Source/build/features.g...
Source/build/features.gypi:46: 'gc_profile_free_list%': 0,
I tried to add a build flag but it is incomplete.

https://codereview.chromium.org/717923005/diff/170001/Source/platform/heap/Ha...
File Source/platform/heap/Handle.h (right):

https://codereview.chromium.org/717923005/diff/170001/Source/platform/heap/Ha...
Source/platform/heap/Handle.h:422: //    m_tracingName =
Heap::createBacktraceString();
I forgot why I did this.

https://codereview.chromium.org/717923005/diff/170001/Source/platform/heap/He...
File Source/platform/heap/Heap.cpp (right):

https://codereview.chromium.org/717923005/diff/170001/Source/platform/heap/He...
Source/platform/heap/Heap.cpp:71: static ObjectAgeMap& uom()
Unmarked object map.

https://codereview.chromium.org/717923005/diff/170001/Source/platform/heap/He...
Source/platform/heap/Heap.cpp:83: static ObjectAgeMap& mom()
Marked object map.

https://codereview.chromium.org/717923005/diff/170001/Source/platform/heap/He...
Source/platform/heap/Heap.cpp:728: setAllocationPoint(nullptr, 0);
The changes below to outOfLineAllocate and allocateFromFreeList are unrelated
experiment that just got mixed in by mistake.

https://codereview.chromium.org/717923005/diff/170001/Source/platform/heap/He...
Source/platform/heap/Heap.cpp:1924: void
HeapPage<Header>::countUnmarkedObjects()
Scans heap for objects that haven't been marked, and collect stats on them to
uom().

https://codereview.chromium.org/717923005/diff/170001/Source/platform/heap/He...
Source/platform/heap/Heap.cpp:2125: ObjectAgeMap::AddResult result =
mom().add(className, AgeHistogram());
Record that the object has been marked to mom()

https://codereview.chromium.org/717923005/diff/170001/Source/platform/heap/He...
File Source/platform/heap/Heap.h (right):

https://codereview.chromium.org/717923005/diff/170001/Source/platform/heap/He...
Source/platform/heap/Heap.h:883: size_t m_allocationPointSizeSum = 0;
Used to report average allocation point size between snapshots. Wasn't very
helpful so I think we don't need this metric.

[keishi, 2015-01-27 09:45:12]

keishi@chromium.org changed reviewers:
+ yutak@chromium.org

[keishi, 2015-01-27 09:45:13]

## Instructions

Step 1: Apply patch to chromium
This adds trace-blinkgc profiler mode.
$ git cl patch 745493002

Step 2: Apply patch to WebKit
$ git cl patch 717923005

Step 3: Build with GYP_DEFINES="gc_profile_free_list=1 gc_profile_free_list=1"

Step 4: Run benchmark with profiler

Running entire page sets causes timeouts so I run them one at a time.

$ tools/perf/run_benchmark run --browser=release --profiler=trace-blinkgc
--page-filter=StyleSheetInsert.html blink_perf.css

Step 5: Load tracing JSON file in go/oilpanfragmentation

## Code overview

I'm sorry that the code is so adhoc. Ask me if you have any questions.

Data for tracing JSON is generated in ThreadState::snapshotFreeList(),
MarkingVisitor::reportMarkingStats(), and Heap::reportSweepingStats().

snapshotFreeList() records stats about the heap.
reportMarkingStats() records stats for every marking.
reportSweepingStats() records stats for every sweeping.

The chromium side changes had to be made because, on my machine, telemetry timed
out when receiving large tracing json files.
https://codereview.chromium.org/745493002/

I rebased the CL just now (Patch set 11) so that should compile, but from what I
remember, it crashes when trying to modify uom() or mom().