Closed Bug 499968 Opened 16 years ago Closed 7 years ago

ZCT reaping times are not bounded

Categories

(Tamarin Graveyard :: Garbage Collection (mmGC), defect, P3)

ARM
Windows Mobile 6 Professional
defect

Tracking

(Not tracked)

RESOLVED WONTFIX
Q1 12 - Brannan

People

(Reporter: lhansen, Unassigned)

References

Details

On slow platforms like WinMo the ZCT reaping can actually take more time than a mark increment or the finalization phase of GC, even with moderate heap sizes. It's possible that the ZCT reap times need to be bounded somehow, like incremental mark pauses are.
Blocks: 501916
With the changes pending in bug #506012 this might now be possible. It would go like the following. The reaper would operate like IncrementalMark. It would be given a time slice and it would check the performance counter every k pointers. If the time slice expires, the pinned objects would be copied from the pinning memory onto the ZCT (there are usually very few of these), any pinned objects in the untouched part of the ZCT would be unpinned, and reaping would terminate normally. If invoked from the GC the reap budget would be subtracted from the budget of the caller. If there is a correspondence between how long an element has been in the ZCT and how likely it is that it will be pinned then eg oldest-first reaping might make sense, but there's no particular reason to believe that there is such a correspondence so we'd want evidence for it first.
Target Milestone: --- → Future
Assignee: lhansen → nobody
Status: ASSIGNED → NEW
Priority: -- → P3
Target Milestone: Future → flash10.2
Whiteboard: PACMAN
Whiteboard: PACMAN
Deferring since RC is likely to go away post-Serrano and the gains for Serrano would be small.
Priority: P3 → --
Target Milestone: flash10.x - Serrano → Future
Blocks: 604350
Priority: -- → P3
Target Milestone: Future → Q1 12 - Brannan
Tamarin is a dead project now. Mass WONTFIX.
Status: NEW → RESOLVED
Closed: 7 years ago
Resolution: --- → WONTFIX
Tamarin isn't maintained anymore. WONTFIX remaining bugs.
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