On Wed, Jul 15, 2015 at 12:03:18PM -0700, Andres Lagar-Cavilla wrote: > For both /proc/kpage* interfaces you add (and more critically for the > rmap-causing one, kpageidle): > > It's a good idea to do cond_sched(). Whether after each pfn, each Nth > pfn, each put_user, I leave to you, but a reasonable cadence is > needed, because user-space can call this on the entire physical > address space, and that's a lot of work to do without re-scheduling. I really don't think it's necessary. These files can only be read/written by the root, who has plenty ways to kill the system anyway. The program that is allowed to read/write these files must be conscious and do it in batches of reasonable size. AFAICS the same reasoning already lays behind /proc/kpagecount and /proc/kpageflag, which also do not thrust the "right" batch size on their readers. Thanks, Vladimir -- 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>