On Wed 29-06-16 22:14:09, Oleg Nesterov wrote: > On 06/28, Michal Hocko wrote: > > > > On Mon 27-06-16 19:55:55, Oleg Nesterov wrote: > > > On 06/27, Michal Hocko wrote: > > > > > > > > On Mon 27-06-16 17:51:20, Oleg Nesterov wrote: > > > > > > > > > > Yes I agree, it would be nice to remove find_lock_task_mm(). And in > > > > > fact it would be nice to kill task_struct->mm (but this needs a lot > > > > > of cleanups). We probably want signal_struct->mm, but this is a bit > > > > > complicated (locking). > > > > > > > > Is there any hard requirement to reset task_struct::mm in the first > > > > place? > > > > > > Well, at least the scheduler needs this. > > > > Could you point me to where it depends on that? I mean if we are past > > exit_mm then we have unmapped the address space most probably but why > > should we care about that in the scheduler? There shouldn't be any > > further access to the address space by that point. I can see that > > context_switch() checks task->mm but it should just work when it sees it > > non NULL, right? > > But who will do the final mmdrop() then? I am not saying this is impossible > to change, say we do this in finish_task_switch(TASK_DEAD) or even in > free_task(), but we do not want this? I thought it could be done somewhere in release_task after we unhash the process but then we would need something for the exlusion (possibly task_lock) to handle races when the oom killer sees a task while it is being unhashed. I guess it should be doable... -- 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>