On Tue, May 25, 2010 at 09:55:28AM +0300, Pekka Enberg wrote: > On Tue, May 25, 2010 at 5:06 AM, Nick Piggin <npiggin@xxxxxxx> wrote: > >> If can find criteria that are universally agreed upon then yes but that is > >> doubtful. > > > > I think we can agree that perfect is the enemy of good, and that no > > allocator will do the perfect thing for everybody. I think we have to > > come up with a way to a single allocator. > > Yes. The interesting most interesting bit about SLEB for me is the > freelist handling as bitmaps, not necessarily the "queuing" part. If > the latter also helps some workloads, it's a bonus for sure. Agreed it is all interesting, but I think we have to have a rational path toward having just one. There is nothing to stop incremental changes or tweaks on top of that allocator, even to the point of completely changing the allocation scheme. It is inevitable that with changes in workloads, SMP/NUMA, and cache/memory costs and hierarchies, the best slab allocation schemes will change over time. I think it is more important to have one allocator than trying to get the absolute most perfect one for everybody. That way changes are carefully and slowly reviewed and merged, with results to justify the change. This way everybody is testing the same thing, and bisection will work. The situation with SLUB is already a nightmare because now each allocator has half the testing and half the work put into it. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>