On Fri 03-09-10 19:05:20, KAMEZAWA Hiroyuki wrote: > On Fri, 3 Sep 2010 11:50:49 +0200 > Michal Hocko <mhocko@xxxxxxx> wrote: > > > On Fri 03-09-10 18:13:27, KAMEZAWA Hiroyuki wrote: > > > On Fri, 3 Sep 2010 10:25:58 +0200 > > > Michal Hocko <mhocko@xxxxxxx> wrote: > > > > > > > On Fri 03-09-10 12:14:52, KAMEZAWA Hiroyuki wrote: > > > > [...] > > [...] > > > > Cannot ZONE_MOVABLE contain different MIGRATE_types? > > > > > > > never. > > > > Then I am terribly missing something. Zone contains free lists for > > different MIGRATE_TYPES, doesn't it? Pages allocated from those free > > lists keep the migration type of the list, right? > > > > ZONE_MOVABLE just says whether it makes sense to move pages in that zone > > at all, right? > > > > ZONE_MOVABLE means "it only contains MOVABLE pages." > So, we can ignore migrate-type. Ahh. OK, it seems that I have to look over movable related code once again. Maybe I just got confused from my experience when ZONE_MOVABLE zone contained MIGRATE_RESERVE pages but now I can see that this is OK and doesn't have anything to do with other migrate types. Anyway, thank you for clarification. [...] > > > > Isn't this a problem? The function is triggered from userspace by sysfs > > > > (0444 file) and holds the lock for pageblock_nr_pages. So someone can > > > > simply read the file and block the zone->lock preventing/delaying > > > > allocations for the rest of the system. > > > > > > > But we need to take this. Maybe no panic you'll see even if no-lock. > > > > Yes, I think that this can only lead to a false possitive in sysfs > > interface. Isolating code holds the lock. > > > > ok, let's go step by step. > > I'm ok that your new patch to be merged. I'll post some clean up and small > bugfix (not related to your patch), later. > (I'll be very busy in this weekend, sorry.) OK, no problem, we are not in hurry ;) > > > Thanks, > -Kame > Thanks! -- Michal Hocko L3 team SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>