1115139 - Scale free pool minimum size with heap size

Status: NEW

(Core :: JavaScript: GC, defect)

Description

[Terrence Cole [:terrence]]

The allocations we make when tenuring are some of the most likely to OOM. We are more likely to OOM when our runtime is close to the memory limit because (1) there is less memory available and (2) that runtime is likely to be allocating heavily. The semi-obvious solution is keep more pre-allocated chunks in the free pool, so that memory is more likely to be available during minor GCs and hopefully make the first OOM happen on a malloc, where we can recover, somewhat.

Comment 1

[Terrence Cole [:terrence]]

This will probably work even better if we make the empty chunk pool global as well.

Comment 2

[demiobenour]

Can we guarantee that at the start of any GC, we have enough memory reserved to finish that GC?

Comment 3

[Jon Coppeard (:jonco)]

(In reply to demiobenour from comment #2)
> Can we guarantee that at the start of any GC, we have enough memory reserved
> to finish that GC?

For a minor GC we may need to allocate as much heap as the size of the nursery.  We cannot guarantee this short of pre-reserving all this memory (which can by up to 16MiB).  But that just moves the OOM somewhere else and wastes memory when it's not needed.