On Wed 05-11-14 10:44:36, Tejun Heo wrote: > On Wed, Nov 05, 2014 at 02:42:19PM +0100, Michal Hocko wrote: > > On Wed 05-11-14 14:31:00, Michal Hocko wrote: > > > On Wed 05-11-14 08:02:47, Tejun Heo wrote: > > [...] > > > > Also, why isn't this part of > > > > oom_killer_disable/enable()? The way they're implemented is really > > > > silly now. It just sets a flag and returns whether there's a > > > > currently running instance or not. How were these even useful? > > > > Why can't you just make disable/enable to what they were supposed to > > > > do from the beginning? > > > > > > Because then we would block all the potential allocators coming from > > > workqueues or kernel threads which are not frozen yet rather than fail > > > the allocation. > > > > After thinking about this more it would be doable by using trylock in > > the allocation oom path. I will respin the patch. The API will be > > cleaner this way. > > In disable, block new invocations of OOM killer and then drain the > in-progress ones. This is a common pattern, isn't it? 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. -- Michal Hocko SUSE Labs -- 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>