Re: [PATCH 3/3] mm: oom: show unreclaimable slab info when unreclaimable slabs > user memory

[Michal Hocko]

On Sat 07-10-17 00:37:55, Yang Shi wrote:
> 
> 
> On 10/6/17 2:37 AM, Michal Hocko wrote:
> > On Thu 05-10-17 05:29:10, Yang Shi wrote:
[...]
> > > +	list_for_each_entry_safe(s, s2, &slab_caches, list) {
> > > +		if (!is_root_cache(s) || (s->flags & SLAB_RECLAIM_ACCOUNT))
> > > +			continue;
> > > +
> > > +		memset(&sinfo, 0, sizeof(sinfo));
> > 
> > why do you zero out the structure. All the fields you are printing are
> > filled out in get_slabinfo.
> 
> No special reason, just wipe out the potential stale data on the stack.

Do not add code that has no meaning. The OOM killer is a slow path but
that doesn't mean we should throw spare cycles out of the window.
-- 
Michal Hocko
SUSE Labs