On Mon 12-06-17 13:53:51, Vlastimil Babka wrote:
> On 06/12/2017 11:06 AM, Michal Hocko wrote:
[...]
> > -/* Movability of hugepages depends on migration support. */
> > -static inline gfp_t htlb_alloc_mask(struct hstate *h)
> > +static struct page *dequeue_huge_page_node(struct hstate *h, int nid)
> > {
> > - if (hugepages_treat_as_movable || hugepage_migration_supported(h))
> > - return GFP_HIGHUSER_MOVABLE;
> > - else
> > - return GFP_HIGHUSER;
> > + if (nid != NUMA_NO_NODE)
> > + return dequeue_huge_page_node_exact(h, nid);
> > +
> > + return dequeue_huge_page_nodemask(h, nid, NULL);
>
> This with nid == NUMA_NO_NODE will break at node_zonelist(nid,
> gfp_mask); in dequeue_huge_page_nodemask(). I guess just use the local
> node as preferred.
You are right. Anyway I have a patch to remove this helper altogether.
> > -retry_cpuset:
> > - cpuset_mems_cookie = read_mems_allowed_begin();
> > - gfp_mask = htlb_alloc_mask(h);
> > - nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
> > - zonelist = node_zonelist(nid, gfp_mask);
> > -
> > - for_each_zone_zonelist_nodemask(zone, z, zonelist,
> > - MAX_NR_ZONES - 1, nodemask) {
> > - if (cpuset_zone_allowed(zone, gfp_mask)) {
> > - page = dequeue_huge_page_node(h, zone_to_nid(zone));
> > - if (page) {
> > - if (avoid_reserve)
> > - break;
> > - if (!vma_has_reserves(vma, chg))
> > - break;
> > -
> > - SetPagePrivate(page);
> > - h->resv_huge_pages--;
> > - break;
> > - }
> > - }
> > + nid = huge_node(vma, address, htlb_alloc_mask(h), &mpol, &nodemask);
> > + page = dequeue_huge_page_nodemask(h, nid, nodemask);
> > + if (page && !(avoid_reserve || (!vma_has_reserves(vma, chg)))) {
>
> Ugh that's hard to parse.
> What about: if (page && !avoid_reserve && vma_has_reserves(...)) ?
Yeah, I have just translated the two breaks into a single condition
without scratching my head to much. If you think that this face of De Morgan
is nicer I can use it.
--
Michal Hocko
SUSE Labs
