On Thu 28-09-17 01:25:50, Yang Shi wrote: > > > On 9/27/17 3:45 AM, Michal Hocko wrote: > > On Wed 27-09-17 08:53:35, Yang Shi wrote: > > > Kernel may panic when oom happens without killable process sometimes it > > > is caused by huge unreclaimable slabs used by kernel. > > > > > > Although kdump could help debug such problem, however, kdump is not > > > available on all architectures and it might be malfunction sometime. > > > And, since kernel already panic it is worthy capturing such information > > > in dmesg to aid touble shooting. > > > > > > Print out unreclaimable slab info (used size and total size) which > > > actual memory usage is not zero (num_objs * size != 0) when: > > > - unreclaimable slabs : all user memory > unreclaim_slabs_oom_ratio > > > - panic_on_oom is set or no killable process > > > > OK, this is better but I do not see why this should be tunable via proc. > > Just thought someone might want to dump unreclaimable slab info > unconditionally.
If that ever happens then we will eventually add it. But do not add proc knobs for theoretical usecases. We will have to maintain them and it can turn into a maint. pain. Like some others in the past. -- Michal Hocko SUSE Labs
