On Wed, 14 Mar 2018, Roman Gushchin wrote:
> > @@ -2618,92 +2620,65 @@ static long memcg_oom_badness(struct mem_cgroup *memcg,
> > if (nodemask && !node_isset(nid, *nodemask))
> > continue;
> >
> > - points += mem_cgroup_node_nr_lru_pages(memcg, nid,
> > - LRU_ALL_ANON | BIT(LRU_UNEVICTABLE));
> > -
> > pgdat = NODE_DATA(nid);
> > - points += lruvec_page_state(mem_cgroup_lruvec(pgdat, memcg),
> > - NR_SLAB_UNRECLAIMABLE);
> > + if (is_root_memcg) {
> > + points += node_page_state(pgdat, NR_ACTIVE_ANON) +
> > + node_page_state(pgdat, NR_INACTIVE_ANON);
> > + points += node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE);
> > + } else {
> > + points += mem_cgroup_node_nr_lru_pages(memcg, nid,
> > + LRU_ALL_ANON);
> > + points += lruvec_page_state(mem_cgroup_lruvec(pgdat, memcg),
> > + NR_SLAB_UNRECLAIMABLE);
> > + }
> > }
> >
> > - points += memcg_page_state(memcg, MEMCG_KERNEL_STACK_KB) /
> > - (PAGE_SIZE / 1024);
> > - points += memcg_page_state(memcg, MEMCG_SOCK);
> > - points += memcg_page_state(memcg, MEMCG_SWAP);
> > -
> > + if (is_root_memcg) {
> > + points += global_zone_page_state(NR_KERNEL_STACK_KB) /
> > + (PAGE_SIZE / 1024);
> > + points += atomic_long_read(&total_sock_pages);
> ^^^^^^^^^^^^^^^^
> BTW, where do we change this counter?
>
Seems like it was dropped from the patch somehow. It is intended to do
atomic_long_add(nr_pages) in mem_cgroup_charge_skmem() and
atomic_long_add(-nr_pages) mem_cgroup_uncharge_skmem().
> I also doubt that global atomic variable can work here,
> we probably need something better scaling.
>
Why do you think an atomic_long_add() is too expensive when we're already
disabling irqs and dong try_charge()?
