[GC] Change behavior when reaching external allocation limit

With the recent changes to the incremental marking API we can now kick off
incremental marking while respecting callback flags.

Performance neutral for smoothness.image_decoding_cases on N9 (read: does not
crash) as long as we synchronously process phantom callbacks
(kGCCallbackFlagForced).

OORT single run:
  "marksweep": {
    "count": 5,
    "pause_min": 7.5,
    "pause_max": 158.8,
    "pause_avg": 97.52000000000001,
    "pause_gt_10ms": 4
  }
  --- vs ---
  "marksweep": {
    "count": 5,
    "pause_min": 16.2,
    "pause_max": 22.1,
    "pause_avg": 19.32,
    "pause_gt_10ms": 5
  }

The number of actual full GCs varies. The improvement manifests in reduced
maximum and average pauses.

BUG=chromium:515795
LOG=N

Review URL: https://codereview.chromium.org/1271253002

Cr-Commit-Position: refs/heads/master@{#30028}
2 files changed
tree: 7e8682424d3492f7b040184af1eeb1460748b6e9
  1. benchmarks/
  2. build/
  3. include/
  4. infra/
  5. samples/
  6. src/
  7. test/
  8. testing/
  9. third_party/
  10. tools/
  11. .clang-format
  12. .gitignore
  13. .ycm_extra_conf.py
  14. AUTHORS
  15. BUILD.gn
  16. ChangeLog
  17. codereview.settings
  18. DEPS
  19. LICENSE
  20. LICENSE.strongtalk
  21. LICENSE.v8
  22. LICENSE.valgrind
  23. Makefile
  24. Makefile.android
  25. Makefile.nacl
  26. OWNERS
  27. PRESUBMIT.py
  28. README.md
  29. WATCHLISTS
README.md

V8 JavaScript Engine

V8 is Google's open source JavaScript engine.

V8 implements ECMAScript as specified in ECMA-262.

V8 is written in C++ and is used in Google Chrome, the open source browser from Google.

V8 can run standalone, or can be embedded into any C++ application.

V8 Project page: https://code.google.com/p/v8/

Getting the Code

Checkout depot tools, and run

    fetch v8

This will checkout V8 into the directory v8 and fetch all of its dependencies. To stay up to date, run

    git pull origin
    gclient sync

For fetching all branches, add the following into your remote configuration in .git/config:

    fetch = +refs/branch-heads/*:refs/remotes/branch-heads/*
    fetch = +refs/tags/*:refs/tags/*