On Wed, Nov 05, 2014 at 05:39:56PM +0100, Michal Hocko wrote: > On Wed 05-11-14 11:29:29, Tejun Heo wrote: > > Hello, Michal. > > > > On Wed, Nov 05, 2014 at 05:01:15PM +0100, Michal Hocko wrote: > > > I am not sure I am following. With the latest patch OOM path is no > > > longer blocked by the PM (aka oom_killer_disable()). Allocations simply > > > fail if the read_trylock fails. > > > oom_killer_disable is moved before tasks are frozen and it will wait for > > > all on-going OOM killers on the write lock. OOM killer is enabled again > > > on the resume path. > > > > Sure, but why are we exposing new interfaces? Can't we just make > > oom_killer_disable() first set the disable flag and wait for the > > on-going ones to finish (and make the function fail if it gets chosen > > as an OOM victim)? > > Still not following. How do you want to detect an on-going OOM without > any interface around out_of_memory? I thought you were using oom_killer_allowed_start() outside OOM path. Ugh.... why is everything weirdly structured? oom_killer_disabled implies that oom killer may fail, right? Why is __alloc_pages_slowpath() checking it directly? If whether oom killing failed or not is relevant to its users, make out_of_memory() return an error code. There's no reason for the exclusion detail to leak out of the oom killer proper. The only interface should be disable/enable and whether oom killing failed or not. Thanks. -- tejun -- 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>