On Tue, Nov 03, 2009 at 10:30:24AM +0100, Thomas Bogendoerfer wrote: > On Mon, Nov 02, 2009 at 04:12:35PM -0800, David Daney wrote: > > On SMP systems, the collection of statistics can cause cache line > > bouncing in the lines associated with the counters. Make the > > statistics configurable so this can be avoided. Also we need to make > > the counters atomic_t so that they can be reliably modified on SMP > > systems. > > how about making it a per_cpu thing and avoid the atomic instructions ? Working on that. The tricky part is that statistics may end up somewhat inaccurate when a reader iterates over the per-CPU array of stats to add them all up. I've not found a solution for that yet but then again it should not be something which actually would cause pain. Ralf
