[heap] Reland "Verify remembered set for objects in the old generation."

[heap] Reland "Verify remembered set for objects in the old generation."

This reverts commit 8f89e28661af23b0aa163a265d906bf6a194fe3d.

Review-Url: https://codereview.chromium.org/2876503002
Cr-Commit-Position: refs/heads/master@{#45229}
Committed: https://chromium.googlesource.com/v8/v8/+/69c6970fae793655d07571e71b63ddb0c095d865

[ulan, 2017-05-10 11:27:11]

Description was changed from

==========
[heap] Reland Verify remembered set for objects in the old generation.

This reverts commit 8f89e28661af23b0aa163a265d906bf6a194fe3d.
==========

to

==========
[heap] Reland "Verify remembered set for objects in the old generation."

This reverts commit 8f89e28661af23b0aa163a265d906bf6a194fe3d.
==========

[ulan, 2017-05-10 11:27:32]

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

[ulan, 2017-05-10 11:27:32]

ptal, the fix is in the diff between the patch sets.

[Michael Lippautz, 2017-05-10 11:28:09]

lgtm

[ulan, 2017-05-10 12:11:19]

The CQ bit was checked by ulan@chromium.org

[commit-bot: I haz the power, 2017-05-10 12:11:27]

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, 2017-05-10 12:41:23]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1494418279676200,
"parent_rev": "936b3d8d66ed9d3492039dc4ec11a5da07fc195c", "commit_rev":
"69c6970fae793655d07571e71b63ddb0c095d865"}

[commit-bot: I haz the power, 2017-05-10 12:41:30]

Description was changed from

==========
[heap] Reland "Verify remembered set for objects in the old generation."

This reverts commit 8f89e28661af23b0aa163a265d906bf6a194fe3d.
==========

to

==========
[heap] Reland "Verify remembered set for objects in the old generation."

This reverts commit 8f89e28661af23b0aa163a265d906bf6a194fe3d.

Review-Url: https://codereview.chromium.org/2876503002
Cr-Commit-Position: refs/heads/master@{#45229}
Committed:
https://chromium.googlesource.com/v8/v8/+/69c6970fae793655d07571e71b63ddb0c09...
==========

[commit-bot: I haz the power, 2017-05-10 12:41:31]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/69c6970fae793655d07571e71b63ddb0c09...

[Michael Achenbach, 2017-05-11 09:09:01]

machenbach@chromium.org changed reviewers:
+ machenbach@chromium.org

[Michael Achenbach, 2017-05-11 09:09:02]

Note, this seems to decrease test performance in debug quite a lot. Is there a
way to improve the speed? Otherwise I'll bump swarming shards to tackle the
extra load...

[ulan, 2017-05-11 09:10:29]

On 2017/05/11 09:09:02, Michael Achenbach wrote:
> Note, this seems to decrease test performance in debug quite a lot. Is there a
> way to improve the speed? Otherwise I'll bump swarming shards to tackle the
> extra load...

How much is the slow down? I can add a flag for this verification mode so that
we can enable it selectively on some bots.

[Michael Achenbach, 2017-05-11 09:22:16]

On 2017/05/11 09:10:29, ulan wrote:
> On 2017/05/11 09:09:02, Michael Achenbach wrote:
> > Note, this seems to decrease test performance in debug quite a lot. Is there
a
> > way to improve the speed? Otherwise I'll bump swarming shards to tackle the
> > extra load...
> 
> How much is the slow down? I can add a flag for this verification mode so that
> we can enable it selectively on some bots.

Looks like around 10-20%. Flag maybe not - would maybe make the infrastructure
to inhomogeneous. Unless, is there a flag to turn it off? I could turn it off on
one or two of the slowest bots like
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%...
- or could I just turn of verify-heap entirely?

[ulan, 2017-05-11 09:26:11]

On 2017/05/11 09:22:16, Michael Achenbach wrote:
> On 2017/05/11 09:10:29, ulan wrote:
> > On 2017/05/11 09:09:02, Michael Achenbach wrote:
> > > Note, this seems to decrease test performance in debug quite a lot. Is
there
> a
> > > way to improve the speed? Otherwise I'll bump swarming shards to tackle
the
> > > extra load...
> > 
> > How much is the slow down? I can add a flag for this verification mode so
that
> > we can enable it selectively on some bots.
> 
> Looks like around 10-20%. Flag maybe not - would maybe make the infrastructure
> to inhomogeneous. Unless, is there a flag to turn it off? I could turn it off
on
> one or two of the slowest bots like
>
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%...
> - or could I just turn of verify-heap entirely?

I would keep verify heap. I can add a flag to turn it off. sg?

[Michael Achenbach, 2017-05-11 09:29:15]

On 2017/05/11 09:26:11, ulan wrote:
> On 2017/05/11 09:22:16, Michael Achenbach wrote:
> > On 2017/05/11 09:10:29, ulan wrote:
> > > On 2017/05/11 09:09:02, Michael Achenbach wrote:
> > > > Note, this seems to decrease test performance in debug quite a lot. Is
> there
> > a
> > > > way to improve the speed? Otherwise I'll bump swarming shards to tackle
> the
> > > > extra load...
> > > 
> > > How much is the slow down? I can add a flag for this verification mode so
> that
> > > we can enable it selectively on some bots.
> > 
> > Looks like around 10-20%. Flag maybe not - would maybe make the
infrastructure
> > to inhomogeneous. Unless, is there a flag to turn it off? I could turn it
off
> on
> > one or two of the slowest bots like
> >
>
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%...
> > - or could I just turn of verify-heap entirely?
> 
> I would keep verify heap. I can add a flag to turn it off. sg?

Jep, sg. Then we'd have it on by default and turn it off on our slowest bots.

[Michael Achenbach, 2017-05-11 09:29:15]

On 2017/05/11 09:26:11, ulan wrote:
> On 2017/05/11 09:22:16, Michael Achenbach wrote:
> > On 2017/05/11 09:10:29, ulan wrote:
> > > On 2017/05/11 09:09:02, Michael Achenbach wrote:
> > > > Note, this seems to decrease test performance in debug quite a lot. Is
> there
> > a
> > > > way to improve the speed? Otherwise I'll bump swarming shards to tackle
> the
> > > > extra load...
> > > 
> > > How much is the slow down? I can add a flag for this verification mode so
> that
> > > we can enable it selectively on some bots.
> > 
> > Looks like around 10-20%. Flag maybe not - would maybe make the
infrastructure
> > to inhomogeneous. Unless, is there a flag to turn it off? I could turn it
off
> on
> > one or two of the slowest bots like
> >
>
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%...
> > - or could I just turn of verify-heap entirely?
> 
> I would keep verify heap. I can add a flag to turn it off. sg?

Jep, sg. Then we'd have it on by default and turn it off on our slowest bots.