Use the same GC threshold regardless of whether the last GC was a shrinking GC
Categories
(Core :: JavaScript: GC, task, P3)
Tracking
()
| Tracking | Status | |
|---|---|---|
| firefox93 | --- | fixed |
People
(Reporter: jonco, Assigned: jonco)
Details
Attachments
(1 file)
|
Bug 1725357 - Use the same GC threshold regardless of whether the last GC was a shrinking GC r?sfink
48 bytes,
text/x-phabricator-request
|
Details | Review |
Currently we change the way we calculate the heap size threshold for zones based on the kind of the last GC. If it was a normal GC then we clamp the current heap size input to a minimum value. With default settings this means we never automatically trigger a GC when the heap size is less than ~35MB.
If the previous GC was a shrinking GC however then we use a different minimum which has the effect of allowing the threshold to be much smaller, potentially as small as 1MB. Subsequent non-shrinking GCs are not affected and the threshold will return to its usual size.
I don't think this has much benefit. It doesn't result in us reclaiming any more memory, only potentially performing GC sooner immediately after a shrinking GC. I think we should remove this feature and simplify the threshold calculation.
|
Assignee | |
Comment 1•3 years ago
|
||
This removes the condition from GCHeapThreshold::computeZoneTriggerBytes.
Pushed by jcoppeard@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/cf0e21d1c16f Use the same GC threshold regardless of whether the last GC was a shrinking GC r=sfink
|
||
Comment 3•3 years ago
|
||
| bugherder | ||
|
||
Comment 4•3 years ago
|
||
== Change summary for alert #30961 (as of Wed, 18 Aug 2021 10:24:51 GMT) ==
Improvements:
| Ratio | Test | Platform | Options | Absolute values (old vs new) |
|---|---|---|---|---|
| 32% | facebook ContentfulSpeedIndex | android-hw-g5-7-0-arm7-shippable-qr | warm webrender | 917.88 -> 627.42 |
| 31% | facebook ContentfulSpeedIndex | android-hw-g5-7-0-arm7-shippable-qr | warm webrender | 918.08 -> 633.42 |
| 11% | facebook dcf | android-hw-g5-7-0-arm7-shippable-qr | warm webrender | 639.88 -> 572.17 |
| 10% | facebook FirstVisualChange | android-hw-g5-7-0-arm7-shippable-qr | warm webrender | 677.83 -> 606.83 |
| 10% | facebook fcp | android-hw-g5-7-0-arm7-shippable-qr | warm webrender | 656.79 -> 589.83 |
| ... | ... | ... | ... | ... |
| 3% | facebook-cristiano loadtime | android-hw-g5-7-0-arm7-shippable-qr | warm webrender | 1,552.65 -> 1,499.25 |
For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=30961
Description
•