[heap,snapshot] Replace first page size from snapshots with page trimming

[heap,snapshot] Replace first page size from snapshots with page trimming

Replace first page size in the snapshots with a heap logic that trims pages
after deserialization. The snapshot provided page sizes was just an
approximation, while the heap knows exactly where to trim.

Furthermore, trim the pages directly after deserialization, leaving no wiggle
room for further objects. This avoids pollution of the immortal immovable pages
with regular objects, e.g. Contexts. The downside is that we potentially require
expanding the space with a new page.

BUG=chromium:636331
Committed: https://crrev.com/ed8791ea65ea1f37520a5ef71b3ae10150329ed3
Cr-Commit-Position: refs/heads/master@{#39200}

[Michael Lippautz, 2016-09-05 18:16:32]

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

[commit-bot: I haz the power, 2016-09-05 18:16:37]

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, 2016-09-05 18:19:27]

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

[commit-bot: I haz the power, 2016-09-05 18:19:27]

Dry run: Try jobs failed on following builders:
  v8_linux_gcc_compile_rel on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_gcc_compile_rel/bu...)

[Michael Lippautz, 2016-09-06 07:16:11]

Patchset #1 (id:1) has been deleted

[Michael Lippautz, 2016-09-06 07:16:14]

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

[commit-bot: I haz the power, 2016-09-06 07:16:24]

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

[Michael Lippautz, 2016-09-06 07:16:25]

Description was changed from

==========
[heap,snapshot] Remove first page size from snapshots

Replace first page size in the snapshots with a heap logic that tightly trims
pages after deserialization.

BUG=chromium:636331
==========

to

==========
[heap,snapshot] Remove first page size from snapshots

Replace first page size in the snapshots with a heap logic that trims
pages after deserialization.

BUG=chromium:636331
==========

[Michael Lippautz, 2016-09-06 07:23:52]

Description was changed from

==========
[heap,snapshot] Remove first page size from snapshots

Replace first page size in the snapshots with a heap logic that trims
pages after deserialization.

BUG=chromium:636331
==========

to

==========
[heap,snapshot] Remove first page size from snapshots

Replace first page size in the snapshots with a heap logic that trims
pages after deserialization. The snapshot provides page sizes was just
an approximation.

Furthermore, trim the pages directly after deserialization, leaving no
wiggle room for further objects. This avoids pollution of the immortal
immovable pages with regular objects, e.g. Contexts. The downside is that
we potentially require expanding the space with a new page.

BUG=chromium:636331
==========

[Michael Lippautz, 2016-09-06 07:24:28]

Description was changed from

==========
[heap,snapshot] Remove first page size from snapshots

Replace first page size in the snapshots with a heap logic that trims
pages after deserialization. The snapshot provides page sizes was just
an approximation.

Furthermore, trim the pages directly after deserialization, leaving no
wiggle room for further objects. This avoids pollution of the immortal
immovable pages with regular objects, e.g. Contexts. The downside is that
we potentially require expanding the space with a new page.

BUG=chromium:636331
==========

to

==========
[heap,snapshot] Remove first page size from snapshots

Replace first page size in the snapshots with a heap logic that trims pages
after deserialization. The snapshot provided page sizes was just an
approximation, while the heap knows exactly where to trim.

Furthermore, trim the pages directly after deserialization, leaving no wiggle
room for further objects. This avoids pollution of the immortal immovable pages
with regular objects, e.g. Contexts. The downside is that we potentially require
expanding the space with a new page.

BUG=chromium:636331
==========

[commit-bot: I haz the power, 2016-09-06 07:30:31]

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

[commit-bot: I haz the power, 2016-09-06 07:30:32]

Dry run: Try jobs failed on following builders:
  v8_linux64_gyp_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_gyp_rel_ng/build...)
  v8_linux64_gyp_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_gyp_rel_ng_trigg...)

[Michael Lippautz, 2016-09-06 07:52:27]

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

[commit-bot: I haz the power, 2016-09-06 07:52:36]

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

[Michael Lippautz, 2016-09-06 08:07:42]

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

[Michael Lippautz, 2016-09-06 08:07:43]

ptal:
- Daniel: snapshot/
- Ulan: rest

Originally reviewed here: https://codereview.chromium.org/2013713003. Basically,
this is the part that replaces size of first page in snapshots with proper page
trimming in the GC. 

I reverted the larger CL because I needed to investigate regressions. Landing in
smaller chunks now.

[Michael Lippautz, 2016-09-06 08:08:18]

Description was changed from

==========
[heap,snapshot] Remove first page size from snapshots

Replace first page size in the snapshots with a heap logic that trims pages
after deserialization. The snapshot provided page sizes was just an
approximation, while the heap knows exactly where to trim.

Furthermore, trim the pages directly after deserialization, leaving no wiggle
room for further objects. This avoids pollution of the immortal immovable pages
with regular objects, e.g. Contexts. The downside is that we potentially require
expanding the space with a new page.

BUG=chromium:636331
==========

to

==========
[heap,snapshot] Replace first page size from snapshots with page trimming

Replace first page size in the snapshots with a heap logic that trims pages
after deserialization. The snapshot provided page sizes was just an
approximation, while the heap knows exactly where to trim.

Furthermore, trim the pages directly after deserialization, leaving no wiggle
room for further objects. This avoids pollution of the immortal immovable pages
with regular objects, e.g. Contexts. The downside is that we potentially require
expanding the space with a new page.

BUG=chromium:636331
==========

[Michael Lippautz, 2016-09-06 08:10:27]

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

[commit-bot: I haz the power, 2016-09-06 08:10:37]

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, 2016-09-06 08:27:28]

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

[commit-bot: I haz the power, 2016-09-06 08:27:30]

Dry run: Try jobs failed on following builders:
  v8_linux64_avx2_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_avx2_rel_ng/buil...)
  v8_linux64_avx2_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_avx2_rel_ng_trig...)

[ulan, 2016-09-06 08:35:39]

lgtm

[vogelheim, 2016-09-06 08:47:55]

lgtm for src/snapshot/*

[Michael Lippautz, 2016-09-06 10:01:13]

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

[commit-bot: I haz the power, 2016-09-06 10:01:16]

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, 2016-09-06 10:34:37]

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

[commit-bot: I haz the power, 2016-09-06 10:34:38]

Dry run: This issue passed the CQ dry run.

[Michael Lippautz, 2016-09-06 11:00:35]

The CQ bit was checked by mlippautz@chromium.org

[Michael Lippautz, 2016-09-06 11:00:35]

The patchset sent to the CQ was uploaded after l-g-t-m from ulan@chromium.org,
vogelheim@chromium.org
Link to the patchset: https://codereview.chromium.org/2311963002/#ps100001
(title: "Remove debugging print")

[commit-bot: I haz the power, 2016-09-06 11:00:38]

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, 2016-09-06 11:02:24]

Description was changed from

==========
[heap,snapshot] Replace first page size from snapshots with page trimming

Replace first page size in the snapshots with a heap logic that trims pages
after deserialization. The snapshot provided page sizes was just an
approximation, while the heap knows exactly where to trim.

Furthermore, trim the pages directly after deserialization, leaving no wiggle
room for further objects. This avoids pollution of the immortal immovable pages
with regular objects, e.g. Contexts. The downside is that we potentially require
expanding the space with a new page.

BUG=chromium:636331
==========

to

==========
[heap,snapshot] Replace first page size from snapshots with page trimming

Replace first page size in the snapshots with a heap logic that trims pages
after deserialization. The snapshot provided page sizes was just an
approximation, while the heap knows exactly where to trim.

Furthermore, trim the pages directly after deserialization, leaving no wiggle
room for further objects. This avoids pollution of the immortal immovable pages
with regular objects, e.g. Contexts. The downside is that we potentially require
expanding the space with a new page.

BUG=chromium:636331
==========

[commit-bot: I haz the power, 2016-09-06 11:02:25]

Committed patchset #5 (id:100001)

[commit-bot: I haz the power, 2016-09-06 11:03:10]

Description was changed from

==========
[heap,snapshot] Replace first page size from snapshots with page trimming

Replace first page size in the snapshots with a heap logic that trims pages
after deserialization. The snapshot provided page sizes was just an
approximation, while the heap knows exactly where to trim.

Furthermore, trim the pages directly after deserialization, leaving no wiggle
room for further objects. This avoids pollution of the immortal immovable pages
with regular objects, e.g. Contexts. The downside is that we potentially require
expanding the space with a new page.

BUG=chromium:636331
==========

to

==========
[heap,snapshot] Replace first page size from snapshots with page trimming

Replace first page size in the snapshots with a heap logic that trims pages
after deserialization. The snapshot provided page sizes was just an
approximation, while the heap knows exactly where to trim.

Furthermore, trim the pages directly after deserialization, leaving no wiggle
room for further objects. This avoids pollution of the immortal immovable pages
with regular objects, e.g. Contexts. The downside is that we potentially require
expanding the space with a new page.

BUG=chromium:636331

Committed: https://crrev.com/ed8791ea65ea1f37520a5ef71b3ae10150329ed3
Cr-Commit-Position: refs/heads/master@{#39200}
==========

[commit-bot: I haz the power, 2016-09-06 11:03:11]

Patchset 5 (id:??) landed as
https://crrev.com/ed8791ea65ea1f37520a5ef71b3ae10150329ed3
Cr-Commit-Position: refs/heads/master@{#39200}