Closed Bug 1681533 Opened 1 year ago Closed 11 months ago

Major GC collects the nursery more often than necessary

Categories

(Core :: JavaScript: GC, enhancement, P3)

enhancement

Tracking

()

RESOLVED FIXED
86 Branch
Tracking Status
firefox86 --- fixed

People

(Reporter: jonco, Assigned: jonco)

References

Details

Attachments

(1 file)

Currently we can't collect the nursery from inside a major GC slice, which means we have to conservatively collect the nursery beforehand if we see that it might be necessary (this depends on the current incremental state and various other factors).

We should figure out a way to only collect the nursery if it's strictly necessary.

Severity: -- → N/A
Priority: -- → P3

This rearranges a few things so that we can run a minor GC inside a major GC
slice, so we don't have to be conservative about collecting the nursery at the
start of a slice.

Pushed by jcoppeard@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/7da8f779dc24
Only collect the nursery when necessary in major GC r=sfink
Status: NEW → RESOLVED
Closed: 1 year ago
Resolution: --- → FIXED
Target Milestone: --- → 86 Branch
Regressions: 1683870
Backout by smolnar@mozilla.com:
https://hg.mozilla.org/mozilla-central/rev/be8b92759b25
Backed out changeset 7da8f779dc24 at developer's request for causing Bug 1683870. a=backout DONTBUILD
Flags: needinfo?(jcoppeard)
Status: RESOLVED → REOPENED
Resolution: FIXED → ---
Target Milestone: 86 Branch → ---

Hi! Perfherder has detected the improvements below. Do you think these could be a result of the backout?

== Change summary for alert #28321 (as of Mon, 04 Jan 2021 14:51:05 GMT) ==

Improvements:

Ratio Suite Test Platform Options Absolute values (old vs new)
3% JS linux1804-64-shippable-qr 90,031,999.94 -> 87,172,499.05
3% JS linux1804-64-shippable 90,183,823.28 -> 87,887,130.22
2% JS windows10-64-shippable 90,545,819.52 -> 88,487,663.71
2% JS windows10-64-shippable-qr 90,607,945.36 -> 88,795,525.14
2% JS windows10-64-shippable-qr 90,341,385.58 -> 88,777,957.62

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=28321

Bug 1685128 should let us land this without causing AWSY regressions.

Depends on: 1685128
Flags: needinfo?(jcoppeard)
Pushed by jcoppeard@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/982a80b202c3
Only collect the nursery when necessary in major GC r=sfink
Status: REOPENED → RESOLVED
Closed: 1 year ago11 months ago
Resolution: --- → FIXED
Target Milestone: --- → 86 Branch
You need to log in before you can comment on or make changes to this bug.