Support MAP_NORESERVE accounting as part of the new counter.
For each hugepage allocation, at allocation time we check if there is a reservation for this allocation or not. If there is a reservation for this allocation, then this allocation was charged at reservation time, and we don't re-account it. If there is no reserevation for this allocation, we charge the appropriate hugetlb_cgroup.
The hugetlb_cgroup to uncharge for this allocation is stored in page[3].private. We use new APIs added in an earlier patch to set this pointer.
Signed-off-by: Mina Almasry almasrymina@google.com
---
Changes in v10: - Refactored deferred_reserve check.
--- mm/hugetlb.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 9bcfc12c5d214..d3f107626f927 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1374,6 +1374,9 @@ static void __free_huge_page(struct page *page) clear_page_huge_active(page); hugetlb_cgroup_uncharge_page(hstate_index(h), pages_per_huge_page(h), page, false); + hugetlb_cgroup_uncharge_page(hstate_index(h), pages_per_huge_page(h), + page, true); + if (restore_reserve) h->resv_huge_pages++;
@@ -2207,6 +2210,7 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, long gbl_chg; int ret, idx; struct hugetlb_cgroup *h_cg; + bool deferred_reserve;
idx = hstate_index(h); /* @@ -2244,10 +2248,20 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, gbl_chg = 1; }
+ /* If this allocation is not consuming a reservation, charge it now. + */ + deferred_reserve = map_chg || avoid_reserve || !vma_resv_map(vma); + if (deferred_reserve) { + ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), + &h_cg, true); + if (ret) + goto out_subpool_put; + } + ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg, false); if (ret) - goto out_subpool_put; + goto out_uncharge_cgroup_reservation;
spin_lock(&hugetlb_lock); /* @@ -2271,6 +2285,14 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, } hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page, false); + /* If allocation is not consuming a reservation, also store the + * hugetlb_cgroup pointer on the page. + */ + if (deferred_reserve) { + hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, + page, true); + } + spin_unlock(&hugetlb_lock);
set_page_private(page, (unsigned long)spool); @@ -2296,6 +2318,10 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, out_uncharge_cgroup: hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg, false); +out_uncharge_cgroup_reservation: + if (deferred_reserve) + hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), + h_cg, true); out_subpool_put: if (map_chg || avoid_reserve) hugepage_subpool_put_pages(spool, 1); -- 2.25.0.rc1.283.g88dfdc4193-goog