Well I'm glad you've conceded that queues are useful for high performance computing, and that higher order allocations are not a free and unlimited resource. I hope we can move forward now with some objective, testable comparisons and criteria for selecting one main slab allocator. On Fri, May 21, 2010 at 04:14:52PM -0500, Christoph Lameter wrote: > (V2 some more work as time permitted this week) > > SLEB is a merging of SLUB with some queuing concepts from SLAB and a new way > of managing objects in the slabs using bitmaps. It uses a percpu queue so that > free operations can be properly buffered and a bitmap for managing the > free/allocated state in the slabs. It is slightly more inefficient than > SLUB (due to the need to place large bitmaps --sized a few words--in some > slab pages if there are more than BITS_PER_LONG objects in a slab page) but > in general does compete well with SLUB (and therefore also with SLOB) > in terms of memory wastage. > > It does not have the excessive memory requirements of SLAB because > there is no slab management structure nor alien caches. Under NUMA > the remote shared caches are used instead (which may have its issues). > > The SLAB scheme of not touching the object during management is adopted. > SLEB can efficiently free and allocate cache cold objects without > causing cache misses. > > There are numerous SLAB schemes that are not supported. Those could be > added if needed and if they really make a difference. > > WARNING: This only ran successfully using hackbench in kvm instances so far. > But works with NUMA, SMP and UP there. > > V1->V2 Add NUMA capabilities. Refine queue size configurations (not complete). > Test in UP, SMP, NUMA > > -- > 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> -- 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>