On Tue 16-08-16 16:25:12, Oleg Nesterov wrote: > On 08/16, Oleg Nesterov wrote: > > > > On 08/15, Brenden Blanco wrote: > > > > > > Hi folks, > > > > > > I think I have come across a memory leak in uprobes, which is fairly easy > > > to > > > reproduce. > > > > At first glance this looks as a problem in memcg, add CC's... > > > > put_page(old_page) looks properly balanced, and I assume we do not need > > the additional "uncharge", we can rely on __page_cache_release(). > > > > And I do not see any leak if I try to reproduce with CONFIG_MEMCG=n. > > Heh. it seems that mem_cgroup_*() logic was always wrong in __replace_page().
Yes this seems broken since 00501b531c47 ("mm: memcontrol: rewrite charge API") > Could you try the patch below? The patch looks good to me. Thanks! > Oleg. > --- > > --- x/kernel/events/uprobes.c > +++ x/kernel/events/uprobes.c > @@ -200,7 +200,8 @@ static int __replace_page(struct vm_area > > err = 0; > unlock: > - mem_cgroup_cancel_charge(kpage, memcg, false); > + if (err) > + mem_cgroup_cancel_charge(kpage, memcg, false); > mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); > unlock_page(page); > return err; -- Michal Hocko SUSE Labs