PPC/s390: [heap] New heuristics for incremental marking step size.

PPC/s390: [heap] New heuristics for incremental marking step size.

Port: 1beb89f24cb01663843a7519921e7caf0910c760

This patch simplifies code for speeding up marking and
removes write barrier counter.

The step size is now computed based in two parts:
- bytes to mark in order to keep up with allocation,
- bytes to mark in order to make progress.

R=mvstanton@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com, bjaideep@ca.ibm.com
BUG=

Committed: https://crrev.com/429e93bd6be95a7788155dca9901c839b353163e
Cr-Commit-Position: refs/heads/master@{#39876}

[JaideepBajwa, 2016-09-29 14:00:36]

lgtm

[Kelvin Li, 2016-09-29 14:02:13]

The CQ bit was checked by lkelvin@ca.ibm.com

[commit-bot: I haz the power, 2016-09-29 14:02:20]

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, 2016-09-29 14:02:21]

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

[commit-bot: I haz the power, 2016-09-29 14:02:22]

No L-G-T-M from a valid reviewer yet. 
CQ run can only be started by full committers or once the patch has
received an L-G-T-M from a full committer.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
Committers are members of the group "project-v8-committers".
Note that this has nothing to do with OWNERS files.

[john.yan, 2016-09-29 14:06:35]

lgtm

[Kelvin Li, 2016-09-29 14:26:57]

The CQ bit was checked by lkelvin@ca.ibm.com

[commit-bot: I haz the power, 2016-09-29 14:27:03]

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, 2016-09-29 15:15:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-29 15:16:06]

Description was changed from

==========
PPC/s390: [heap] New heuristics for incremental marking step size.

Port: 1beb89f24cb01663843a7519921e7caf0910c760

This patch simplifies code for speeding up marking and
removes write barrier counter.

The step size is now computed based in two parts:
- bytes to mark in order to keep up with allocation,
- bytes to mark in order to make progress.

R=mvstanton@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com, mbrandy@us.ibm.com, bjaideep@ca.ibm.com
BUG=
==========

to

==========
PPC/s390: [heap] New heuristics for incremental marking step size.

Port: 1beb89f24cb01663843a7519921e7caf0910c760

This patch simplifies code for speeding up marking and
removes write barrier counter.

The step size is now computed based in two parts:
- bytes to mark in order to keep up with allocation,
- bytes to mark in order to make progress.

R=mvstanton@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com, mbrandy@us.ibm.com, bjaideep@ca.ibm.com
BUG=

Committed: https://crrev.com/429e93bd6be95a7788155dca9901c839b353163e
Cr-Commit-Position: refs/heads/master@{#39876}
==========

[commit-bot: I haz the power, 2016-09-29 15:16:07]

Patchset 1 (id:??) landed as
https://crrev.com/429e93bd6be95a7788155dca9901c839b353163e
Cr-Commit-Position: refs/heads/master@{#39876}