On Sun, Oct 12, 2014 at 09:28:04AM -0400, Rik van Riel wrote: > On 10/12/2014 09:17 AM, Peter Zijlstra wrote: > >On Wed, Oct 08, 2014 at 03:37:26PM -0400, r...@redhat.com wrote: > >>+ sched_domains_numa_hops = kzalloc(sizeof(int) * nr_node_ids * > >>nr_node_ids, GFP_KERNEL); > >>+ if (!sched_domains_numa_hops) > >>+ return; > > > >That's potentially a _BIG_ table (1M for a 512 node system). > >The node_distance has magic allocations and is of u8 size, is there any > >way we can re-use node_distance and avoid a second O(n^2) allocation? > > You are right, this should be a u8 at the least. > > Beyond that, I am not convinced that merging things into > the same array is worthwhile, since (IIRC) nr_node_ids > should be set to the actual number of nodes on the system > by then.
The thing is, it looks like all you do is compare hop distance, and the order of the hop distances is the exact same order as the regular numa distance. I could not find a place where you use the actual hop value. So if all you're interested in is the relative ordering, that should be the same for both. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/