On Sun, Oct 27, 2013 at 08:30:08AM -0400, Tejun Heo wrote: >On Mon, Oct 21, 2013 at 04:58:11PM +0800, Wei Yang wrote: >> When a cpu belongs to a new group, there is no cpu has the same group id. This >> means it can be assigned a new group id without checking with every others. >> >> This patch does this optimiztion. > >Does this actually matter? If so, it'd probably make a lot more sense >to start inner loop at @cpu + 1 so that it becomes O(N). One of the worst case in my mind: CPU: 0 1 2 3 4 ... Group: 0 1 2 3 4 ... (sounds it is impossible in the real world) Every time, when we encounter a new CPU and try to assign it to a group, we found it belongs to a new group. The original logic will iterate on all old CPUs again, while the new logic could skip this and assign it to a new group. Again, this is a tiny change, which doesn't matters a lot. BTW, I don't get your point for "start inner loop at @cpu+1". The original logic is: loop 1: 0 - nr_cpus loop 2: 0 - (cpu - 1) If you found one better approach to improve the logic, I believe all the users will appreciate your efforts :-) Thanks for your review and comments again ~ > >Thanks. > >-- >tejun -- Richard Yang Help you, Help me -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>