Well, Bas was wondering whether this would be possible. At this point I'm a bit on the fence; on one hand it's not a crucial fix (we have a workaround in usb) and it may involve changes to exported interfaces (although not very high visibility). On the other hand, it's a pretty easy change to make and it cleans up the semantics of the event manager nicely.
I benchmarked your patches on GHC 7.8 branch: -N<n> 1 2 4 8 16 --------------------------------------------------------- head 92,855 155,957 306,813 498,613 527,034 7.8.3 86,494 160,321 310,675 494,020 510,751 7.8.3+ben 84,472 140,978 291,550 488,834 523,837 The inline patch works very nice. :-) # And I was disappointed a bit because GHC does not automatically do # this inline. --Kazu