[heap] Only visit strong links during scavenge of promoted objects

[heap] Only visit strong links during scavenge of promoted objects

Previously, we also used to treat the link as strong, when iterating a promoted
JSFunction.

BUG=chromium:651354
Committed: https://crrev.com/9b5bdfeaebfdd34af5aae9b2bfeacb620cc4707d
Cr-Commit-Position: refs/heads/master@{#41008}

[Michael Lippautz, 2016-11-15 14:14:40]

Description was changed from

==========
[heap] Only record weak slots in JSFuncton during scavenge

Previously, we also used to treat the link as strong, when iterating a promoted
JSFunction.

BUG=
==========

to

==========
[heap] Only record weak slots in JSFuncton during scavenge

Previously, we also used to treat the link as strong, when iterating a promoted
JSFunction.

BUG=chromium:651354
==========

[Michael Lippautz, 2016-11-15 14:14:40]

mlippautz@chromium.org changed reviewers:
+ hpayer@chromium.org, ulan@chromium.org

[Michael Lippautz, 2016-11-15 14:15:37]

ptal; description of the problem is in the minor MC design doc.

https://codereview.chromium.org/2506633002/diff/1/src/heap/heap.h
File src/heap/heap.h (left):

https://codereview.chromium.org/2506633002/diff/1/src/heap/heap.h#oldcode1158
src/heap/heap.h:1158: void IteratePromotedObjectPointers(HeapObject* object,
Address start,
Removed; this should not be on our API.

[ulan, 2016-11-15 14:39:31]

lgtm

https://codereview.chromium.org/2506633002/diff/1/src/heap/heap.cc
File src/heap/heap.cc (right):

https://codereview.chromium.org/2506633002/diff/1/src/heap/heap.cc#newcode4735
src/heap/heap.cc:4735: bool record_slots, ObjectSlotCallback callback)
Can you rename the "callback" to "scavenge" to make it clear that it works only
for scavenger?

Also maybe add a comment that the visitor cannot be called for the same slot
twice.

[Michael Lippautz, 2016-11-15 14:59:50]

Please take another look. We actually record (old->new) slots when going through
the weak lists, which means that we do not need the proposed mode and are just
able to skip the weak links entirely.

https://codereview.chromium.org/2506633002/diff/1/src/heap/heap.cc
File src/heap/heap.cc (right):

https://codereview.chromium.org/2506633002/diff/1/src/heap/heap.cc#newcode4735
src/heap/heap.cc:4735: bool record_slots, ObjectSlotCallback callback)
On 2016/11/15 14:39:31, ulan wrote:
> Can you rename the "callback" to "scavenge" to make it clear that it works
only
> for scavenger?
> 
> Also maybe add a comment that the visitor cannot be called for the same slot
> twice.

Restructured.

[Michael Lippautz, 2016-11-15 15:02:17]

Description was changed from

==========
[heap] Only record weak slots in JSFuncton during scavenge

Previously, we also used to treat the link as strong, when iterating a promoted
JSFunction.

BUG=chromium:651354
==========

to

==========
[heap] Only visit strong links during scavenge of promoted objects

Previously, we also used to treat the link as strong, when iterating a promoted
JSFunction.

BUG=chromium:651354
==========

[ulan, 2016-11-15 15:03:48]

lgtm

[Michael Lippautz, 2016-11-15 15:09:27]

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

[commit-bot: I haz the power, 2016-11-15 15:09:36]

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, 2016-11-15 15:17:08]

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

[commit-bot: I haz the power, 2016-11-15 15:17:09]

Dry run: Try jobs failed on following builders:
  v8_linux_dbg_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_dbg_ng/builds/16272)

[Michael Lippautz, 2016-11-15 15:21:12]

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

[commit-bot: I haz the power, 2016-11-15 15:21:22]

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, 2016-11-15 15:44:37]

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

[commit-bot: I haz the power, 2016-11-15 15:44:38]

Dry run: This issue passed the CQ dry run.

[Hannes Payer (out of office), 2016-11-15 17:13:16]

lgtm

[Michael Lippautz, 2016-11-15 18:19:01]

The CQ bit was checked by mlippautz@chromium.org

[Michael Lippautz, 2016-11-15 18:19:01]

The patchset sent to the CQ was uploaded after l-g-t-m from ulan@chromium.org
Link to the patchset: https://codereview.chromium.org/2506633002/#ps60001
(title: "Fix compilation")

[commit-bot: I haz the power, 2016-11-15 18:19:08]

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, 2016-11-15 18:22:10]

Description was changed from

==========
[heap] Only visit strong links during scavenge of promoted objects

Previously, we also used to treat the link as strong, when iterating a promoted
JSFunction.

BUG=chromium:651354
==========

to

==========
[heap] Only visit strong links during scavenge of promoted objects

Previously, we also used to treat the link as strong, when iterating a promoted
JSFunction.

BUG=chromium:651354
==========

[commit-bot: I haz the power, 2016-11-15 18:22:11]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2016-11-17 22:34:55]

Description was changed from

==========
[heap] Only visit strong links during scavenge of promoted objects

Previously, we also used to treat the link as strong, when iterating a promoted
JSFunction.

BUG=chromium:651354
==========

to

==========
[heap] Only visit strong links during scavenge of promoted objects

Previously, we also used to treat the link as strong, when iterating a promoted
JSFunction.

BUG=chromium:651354

Committed: https://crrev.com/9b5bdfeaebfdd34af5aae9b2bfeacb620cc4707d
Cr-Commit-Position: refs/heads/master@{#41008}
==========

[commit-bot: I haz the power, 2016-11-17 22:34:56]

Patchset 4 (id:??) landed as
https://crrev.com/9b5bdfeaebfdd34af5aae9b2bfeacb620cc4707d
Cr-Commit-Position: refs/heads/master@{#41008}