System.Mem: Expose performMinorGC

We already have

performGC

which triggers a major garbage collection.

In many cases, it is useful to trigger a minor one; exposing it is as simple as Simon Marlow suggested in https://groups.google.com/d/msg/fa.haskell/-q6sINValu8/_Z7odE6O5PsJ.

Trac metadata

Trac field	Value
Version	7.6.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	libraries/base
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	mail@nh2.me
Operating system
Architecture

changed weight to 5

added Tbug Trac import core libraries labels

Implemented in: https://github.com/nh2/packages-base/compare/performMinorGC

(Could not test it because master does not compile for me at the moment.)

Master compiled now, and so does my patch.

changed milestone to %7.8.1

1. .as far as I understood, having only performMinorGC without the ability to inhibit major GCs seems to be of little use, so do you plan on implementing something like

disableMajorGC, enableMajorGC :: IO ()

as well?

It is very useful for us, since our minor GCs are simply coming at the wrong time.

Imagine a loop that does something for 5 ms and then sleeps for 5 ms. Currently, ghc schedules the minor GCs right into the doing something part significantly decreasing its performance. By triggering a minor GC in the pause, it almost never interrupts the active part.

If ghc thinks that it is time for a major collection, we trust its glorious decisions.

disableMajorGC, enableMajorGC :: IO ()

would be a useful addition as well, but are out of the range of this feature request.

mentioned in commit 4fe151ce

closed

Done - thanks!

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

reopened

http://www.haskell.org/pipermail/ghc-devs/2013-September/002673.html

Should be called performGC as in https://github.com/nh2/packages-base/compare/performMinorGC#diff-47720fb082e9d394a3dd535fa60a3da9R49

Trac metadata

Trac field	Value
Resolution	ResolvedFixed → Unresolved

closed

Fixed. I had to recreate the patch since it fell out of sync with master (we deleted some of the code it touched,) and I forgot to --amend my patch with the typofix.

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

added Pnormal label