Initial idle GC logic.

Initial idle GC logic.

Use the speed of previous scavenges to estimate the time required for the next scavenge. When we receive an initial notification, perform a scavenge if we have allocated enough and we estimate we can complete the scavenge before the deadline.

Expand the time recorded for a scavenge to include safepointing and iterating roots.

R=asiva@google.com

Committed: https://github.com/dart-lang/sdk/commit/86f602d0201afbfddd545d003edea0634c371352

[rmacnak, 2017-08-22 23:20:56]

rmacnak@google.com changed reviewers:
+ asiva@google.com

[rmacnak, 2017-08-30 17:42:49]

Description was changed from

==========
Initial idle GC logic.

 - Expand scavenge duration to include safepointing and iterating roots.
 - Track scavenge rate.
==========

to

==========
Initial idle GC logic.

Use the speed of previous scavenges to estimate the time required for the next
scavenge. When we receive an initial notification, perform a scavenge if we have
allocated enough and we estimate we can complete the scavenge before the
deadline.

Expand the time recorded for a scavenge to include safepointing and iterating
roots.
==========

[siva, 2017-08-31 01:17:50]

lgtm with come coments.

Is it possible to add a unit test in dart_api_impl_test.cc that uses this new
API function with some random script in a loop allocating objects and calling
out to a native method which periodically call the Idle Task API function.

https://codereview.chromium.org/3001423002/diff/40001/runtime/vm/scavenger.cc
File runtime/vm/scavenger.cc (right):

https://codereview.chromium.org/3001423002/diff/40001/runtime/vm/scavenger.cc...
runtime/vm/scavenger.cc:439: // complete in a typical idle period.
Maybe update this comment is a little bit more detail explaining the heuristics
used to estimate what is an ideal new space size to trigger a GC and also
explain the magic constants 4000, 512KB and 80% of capacity etc.

https://codereview.chromium.org/3001423002/diff/40001/runtime/vm/scavenger.cc...
runtime/vm/scavenger.cc:476: }
Should have a history of idle notification deadlines which we have been getting
as that might give us a clue about the potential that we may not be able to
complete a scavenge within the deadline if used_in_words goes up.

[rmacnak, 2017-09-01 00:37:01]

Add test and missing safepoint transition, PTAL

https://codereview.chromium.org/3001423002/diff/40001/runtime/vm/scavenger.cc
File runtime/vm/scavenger.cc (right):

https://codereview.chromium.org/3001423002/diff/40001/runtime/vm/scavenger.cc...
runtime/vm/scavenger.cc:439: // complete in a typical idle period.
On 2017/08/31 01:17:50, siva wrote:
> Maybe update this comment is a little bit more detail explaining the
heuristics
> used to estimate what is an ideal new space size to trigger a GC and also
> explain the magic constants 4000, 512KB and 80% of capacity etc.

Done.

https://codereview.chromium.org/3001423002/diff/40001/runtime/vm/scavenger.cc...
runtime/vm/scavenger.cc:476: }
On 2017/08/31 01:17:50, siva wrote:
> Should have a history of idle notification deadlines which we have been
getting
> as that might give us a clue about the potential that we may not be able to
> complete a scavenge within the deadline if used_in_words goes up.

Acknowledged.

[siva, 2017-09-01 02:26:12]

lgtm

[rmacnak, 2017-09-01 16:38:13]

Description was changed from

==========
Initial idle GC logic.

Use the speed of previous scavenges to estimate the time required for the next
scavenge. When we receive an initial notification, perform a scavenge if we have
allocated enough and we estimate we can complete the scavenge before the
deadline.

Expand the time recorded for a scavenge to include safepointing and iterating
roots.
==========

to

==========
Initial idle GC logic.

Use the speed of previous scavenges to estimate the time required for the next
scavenge. When we receive an initial notification, perform a scavenge if we have
allocated enough and we estimate we can complete the scavenge before the
deadline.

Expand the time recorded for a scavenge to include safepointing and iterating
roots.

R=asiva@google.com

Committed:
https://github.com/dart-lang/sdk/commit/86f602d0201afbfddd545d003edea0634c371352
==========

[rmacnak, 2017-09-01 16:38:14]

Committed patchset #6 (id:100001) manually as
86f602d0201afbfddd545d003edea0634c371352 (presubmit successful).