Vlastimil Babka <vbabka@xxxxxxx> writes: > > I'm worried about the "for_each_possible..." approach here and elsewhere > in the patch as it can be rather excessive compared to the online number > of cpus (we've seen BIOSes report large numbers of possible CPU's). IIRC Even if they report a few hundred extra reading some more shared cache lines is very cheap. The prefetcher usually quickly figures out such a pattern and reads it all in parallel. I doubt it will be noticeable, especially not in a slow path like reading something from proc/sys. > the general approach with vmstat is to query just online cpu's / nodes, > and if they go offline, transfer their accumulated stats to some other > "victim"? That's very complicated, and unlikely to be worth it. -Andi -- 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>
