[GC] Change behavior when reaching external allocation limit

[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

Committed: https://crrev.com/1cb27bce6778ac9a168bf9ca371daa00e040620e
Cr-Commit-Position: refs/heads/master@{#30028}

[Michael Lippautz, 2015-08-05 12:08:25]

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

[Michael Lippautz, 2015-08-05 12:08:26]

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc
File src/api.cc (right):

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc#newcode6889
src/api.cc:6889: double kIncrementalMarkingIntervalInMs = 3;
keep local?

[jochen (gone - plz use gerrit), 2015-08-05 12:22:27]

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc
File src/api.cc (right):

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc#newcode6888
src/api.cc:6888: using Heap = i::Heap;
please don't use using.

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc#newcode6889
src/api.cc:6889: double kIncrementalMarkingIntervalInMs = 3;
On 2015/08/05 at 12:08:26, Michael Lippautz wrote:
> keep local?

maybe make it a flag?

[Hannes Payer (out of office), 2015-08-05 12:39:37]

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc
File src/api.cc (right):

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc#newcode6889
src/api.cc:6889: double kIncrementalMarkingIntervalInMs = 3;
I would prefer 1 instead of 3. The smaller the better.

It would be nice to calculate the value, based on memory pressure. More ms for
higher memory pressure. That could be a TODO.

[Michael Lippautz, 2015-08-05 12:55:59]

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc
File src/api.cc (right):

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc#newcode6888
src/api.cc:6888: using Heap = i::Heap;
On 2015/08/05 12:22:27, jochen wrote:
> please don't use using.

Done.

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc#newcode6889
src/api.cc:6889: double kIncrementalMarkingIntervalInMs = 3;
On 2015/08/05 12:22:27, jochen wrote:
> On 2015/08/05 at 12:08:26, Michael Lippautz wrote:
> > keep local?
> 
> maybe make it a flag?

Done.

https://codereview.chromium.org/1271253002/diff/20001/src/api.cc#newcode6889
src/api.cc:6889: double kIncrementalMarkingIntervalInMs = 3;
On 2015/08/05 12:39:36, Hannes Payer wrote:
> I would prefer 1 instead of 3. The smaller the better.
> 
> It would be nice to calculate the value, based on memory pressure. More ms for
> higher memory pressure. That could be a TODO.

1ms it is. Works on N9. 

Agree that it would be better to dynamically adjust the 
time slices.

[jochen (gone - plz use gerrit), 2015-08-05 12:56:57]

lgtm

[Hannes Payer (out of office), 2015-08-05 12:57:53]

LGTM

[Michael Lippautz, 2015-08-05 13:03:58]

The CQ bit was checked by mlippautz@chromium.org

[commit-bot: I haz the power, 2015-08-05 13:04:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1271253002/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1271253002/60001

[commit-bot: I haz the power, 2015-08-05 13:29:38]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-08-05 13:30:01]

Patchset 4 (id:??) landed as
https://crrev.com/1cb27bce6778ac9a168bf9ca371daa00e040620e
Cr-Commit-Position: refs/heads/master@{#30028}