Use the Oilpan heap canary only on 64-bit.

Use the Oilpan heap canary only on 64-bit.

On 64-bit machines, the canary is free, space-wise. But on 32-bit, it doubles
the size of |HeapObjectHeader|, which has incurred a large run-time memory size
increase.

Turn off the canary for now, on 32-bit. Ultimately we may solve the original bug
(633030) by moving the metadata out of line instead of guarding it with a
canary.

BUG=692931, 692624, 633030
Review-Url: https://codereview.chromium.org/2723743003
Cr-Commit-Position: refs/heads/master@{#453802}
Committed: https://chromium.googlesource.com/chromium/src/+/e3d585cce44455344c067ab7a5ebb359fae854f7

[palmer, 2017-02-28 19:38:25]

palmer@chromium.org changed reviewers:
+ haraken@chromium.org, jschuh@chromium.org

[palmer, 2017-02-28 19:39:01]

Let's relieve the performance pain on 32-bit.

[palmer, 2017-02-28 19:39:05]

The CQ bit was checked by palmer@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-02-28 19:39:44]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-02-28 20:04:26]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-02-28 20:04:27]

Dry run: Try jobs failed on following builders:
  linux_android_rel_ng on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_androi...)

[palmer, 2017-02-28 20:19:25]

The CQ bit was checked by palmer@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-02-28 20:20:06]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-02-28 20:43:09]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-02-28 20:43:10]

Dry run: Try jobs failed on following builders:
  android_compile_dbg on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_comp...)

[palmer, 2017-02-28 21:04:09]

The CQ bit was checked by palmer@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-02-28 21:05:58]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[haraken, 2017-02-28 23:46:39]

LGTM, thanks!

[commit-bot: I haz the power, 2017-03-01 01:45:05]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-03-01 01:45:06]

Dry run: This issue passed the CQ dry run.

[palmer, 2017-03-01 02:21:32]

The CQ bit was checked by palmer@chromium.org

[commit-bot: I haz the power, 2017-03-01 02:22:28]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-01 02:55:25]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1488334892462120,
"parent_rev": "bd3c6dd2947f52dab4b3a7c3a8448231c5a60b97", "commit_rev":
"e3d585cce44455344c067ab7a5ebb359fae854f7"}

[commit-bot: I haz the power, 2017-03-01 02:56:14]

Description was changed from

==========
Use the Oilpan heap canary only on 64-bit.

On 64-bit machines, the canary is free, space-wise. But on 32-bit, it doubles
the size of |HeapObjectHeader|, which has incurred a large run-time memory size
increase.

Turn off the canary for now, on 32-bit. Ultimately we may solve the original bug
(633030) by moving the metadata out of line instead of guarding it with a
canary.

BUG=692931,692624,633030
==========

to

==========
Use the Oilpan heap canary only on 64-bit.

On 64-bit machines, the canary is free, space-wise. But on 32-bit, it doubles
the size of |HeapObjectHeader|, which has incurred a large run-time memory size
increase.

Turn off the canary for now, on 32-bit. Ultimately we may solve the original bug
(633030) by moving the metadata out of line instead of guarding it with a
canary.

BUG=692931,692624,633030

Review-Url: https://codereview.chromium.org/2723743003
Cr-Commit-Position: refs/heads/master@{#453802}
Committed:
https://chromium.googlesource.com/chromium/src/+/e3d585cce44455344c067ab7a5eb...
==========

[commit-bot: I haz the power, 2017-03-01 02:56:15]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/e3d585cce44455344c067ab7a5eb...