From b2261026825ed34066b24069359d118098bb1876 Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Wed, 11 Sep 2013 14:21:00 -0700 Subject: [PATCH] mm, hugetlb: fix and clean-up node iteration code to alloc or free Current node iteration code have a minor problem which do one more node rotation if we can't succeed to allocate. For example, if we start to allocate at node 0, we stop to iterate at node 0. Then we start to allocate at node 1 for next allocation. I introduce new macros "for_each_node_mask_to_[alloc|free]" and fix and clean-up node iteration code to alloc or free. This makes code more understandable. Signed-off-by: Joonsoo Kim Reviewed-by: Aneesh Kumar K.V Acked-by: Hillf Danton Cc: Michal Hocko Cc: Naoya Horiguchi Cc: Wanpeng Li Cc: Rik van Riel Cc: Mel Gorman Cc: "Aneesh Kumar K.V" Cc: KAMEZAWA Hiroyuki Cc: Hugh Dickins Cc: Davidlohr Bueso Cc: David Gibson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 143 ++++++++++++++++++++++----------------------------- 1 file changed, 61 insertions(+), 82 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index a698d40d1c3e..08b7595fe3c1 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -772,33 +772,6 @@ static int hstate_next_node_to_alloc(struct hstate *h, return nid; } -static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed) -{ - struct page *page; - int start_nid; - int next_nid; - int ret = 0; - - start_nid = hstate_next_node_to_alloc(h, nodes_allowed); - next_nid = start_nid; - - do { - page = alloc_fresh_huge_page_node(h, next_nid); - if (page) { - ret = 1; - break; - } - next_nid = hstate_next_node_to_alloc(h, nodes_allowed); - } while (next_nid != start_nid); - - if (ret) - count_vm_event(HTLB_BUDDY_PGALLOC); - else - count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); - - return ret; -} - /* * helper for free_pool_huge_page() - return the previously saved * node ["this node"] from which to free a huge page. Advance the @@ -817,6 +790,40 @@ static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) return nid; } +#define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ + for (nr_nodes = nodes_weight(*mask); \ + nr_nodes > 0 && \ + ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ + nr_nodes--) + +#define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ + for (nr_nodes = nodes_weight(*mask); \ + nr_nodes > 0 && \ + ((node = hstate_next_node_to_free(hs, mask)) || 1); \ + nr_nodes--) + +static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed) +{ + struct page *page; + int nr_nodes, node; + int ret = 0; + + for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { + page = alloc_fresh_huge_page_node(h, node); + if (page) { + ret = 1; + break; + } + } + + if (ret) + count_vm_event(HTLB_BUDDY_PGALLOC); + else + count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); + + return ret; +} + /* * Free huge page from pool from next node to free. * Attempt to keep persistent huge pages more or less @@ -826,36 +833,31 @@ static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, bool acct_surplus) { - int start_nid; - int next_nid; + int nr_nodes, node; int ret = 0; - start_nid = hstate_next_node_to_free(h, nodes_allowed); - next_nid = start_nid; - - do { + for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { /* * If we're returning unused surplus pages, only examine * nodes with surplus pages. */ - if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) && - !list_empty(&h->hugepage_freelists[next_nid])) { + if ((!acct_surplus || h->surplus_huge_pages_node[node]) && + !list_empty(&h->hugepage_freelists[node])) { struct page *page = - list_entry(h->hugepage_freelists[next_nid].next, + list_entry(h->hugepage_freelists[node].next, struct page, lru); list_del(&page->lru); h->free_huge_pages--; - h->free_huge_pages_node[next_nid]--; + h->free_huge_pages_node[node]--; if (acct_surplus) { h->surplus_huge_pages--; - h->surplus_huge_pages_node[next_nid]--; + h->surplus_huge_pages_node[node]--; } update_and_free_page(h, page); ret = 1; break; } - next_nid = hstate_next_node_to_free(h, nodes_allowed); - } while (next_nid != start_nid); + } return ret; } @@ -1192,14 +1194,12 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma, int __weak alloc_bootmem_huge_page(struct hstate *h) { struct huge_bootmem_page *m; - int nr_nodes = nodes_weight(node_states[N_MEMORY]); + int nr_nodes, node; - while (nr_nodes) { + for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { void *addr; - addr = __alloc_bootmem_node_nopanic( - NODE_DATA(hstate_next_node_to_alloc(h, - &node_states[N_MEMORY])), + addr = __alloc_bootmem_node_nopanic(NODE_DATA(node), huge_page_size(h), huge_page_size(h), 0); if (addr) { @@ -1211,7 +1211,6 @@ int __weak alloc_bootmem_huge_page(struct hstate *h) m = addr; goto found; } - nr_nodes--; } return 0; @@ -1350,48 +1349,28 @@ static inline void try_to_free_low(struct hstate *h, unsigned long count, static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, int delta) { - int start_nid, next_nid; - int ret = 0; + int nr_nodes, node; VM_BUG_ON(delta != -1 && delta != 1); - if (delta < 0) - start_nid = hstate_next_node_to_alloc(h, nodes_allowed); - else - start_nid = hstate_next_node_to_free(h, nodes_allowed); - next_nid = start_nid; - - do { - int nid = next_nid; - if (delta < 0) { - /* - * To shrink on this node, there must be a surplus page - */ - if (!h->surplus_huge_pages_node[nid]) { - next_nid = hstate_next_node_to_alloc(h, - nodes_allowed); - continue; - } + if (delta < 0) { + for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { + if (h->surplus_huge_pages_node[node]) + goto found; } - if (delta > 0) { - /* - * Surplus cannot exceed the total number of pages - */ - if (h->surplus_huge_pages_node[nid] >= - h->nr_huge_pages_node[nid]) { - next_nid = hstate_next_node_to_free(h, - nodes_allowed); - continue; - } + } else { + for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { + if (h->surplus_huge_pages_node[node] < + h->nr_huge_pages_node[node]) + goto found; } + } + return 0; - h->surplus_huge_pages += delta; - h->surplus_huge_pages_node[nid] += delta; - ret = 1; - break; - } while (next_nid != start_nid); - - return ret; +found: + h->surplus_huge_pages += delta; + h->surplus_huge_pages_node[node] += delta; + return 1; } #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) -- 2.20.1