On Wed, 2011-02-02 at 01:07 +0100, Andrea Arcangeli wrote: > > I guess we could also try and figure out whether the khugepaged CPU > > overhead really comes from the scanning or the collapsing operations > > themselves. Should be as easy as some oprofiling. > > Actually I already know, the scanning is super fast. So it's no real > big deal to increase the scanning. It's big deal only if there are > plenty more of collapse/split. Compared to the KSM scan, the > khugepaged scan costs nothing. Just FYI, I did some profiling on a workload that constantly split and joined pages. Very little of the overhead was in the scanning itself, so I think you're dead-on here. -- Dave -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>