From ffb29b1c255ab48cb0062a3d11c101501e3e9b3f Mon Sep 17 00:00:00 2001 From: Chen Wandun Date: Thu, 28 Oct 2021 14:36:24 -0700 Subject: [PATCH] mm/vmalloc: fix numa spreading for large hash tables Eric Dumazet reported a strange numa spreading info in [1], and found commit 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings") introduced this issue [2]. Dig into the difference before and after this patch, page allocation has some difference: before: alloc_large_system_hash __vmalloc __vmalloc_node(..., NUMA_NO_NODE, ...) __vmalloc_node_range __vmalloc_area_node alloc_page /* because NUMA_NO_NODE, so choose alloc_page branch */ alloc_pages_current alloc_page_interleave /* can be proved by print policy mode */ after: alloc_large_system_hash __vmalloc __vmalloc_node(..., NUMA_NO_NODE, ...) __vmalloc_node_range __vmalloc_area_node alloc_pages_node /* choose nid by nuam_mem_id() */ __alloc_pages_node(nid, ....) So after commit 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings"), it will allocate memory in current node instead of interleaving allocate memory. Link: https://lore.kernel.org/linux-mm/CANn89iL6AAyWhfxdHO+jaT075iOa3XcYn9k6JJc7JR2XYn6k_Q@mail.gmail.com/ [1] Link: https://lore.kernel.org/linux-mm/CANn89iLofTR=AK-QOZY87RdUZENCZUT4O6a0hvhu3_EwRMerOg@mail.gmail.com/ [2] Link: https://lkml.kernel.org/r/20211021080744.874701-2-chenwandun@huawei.com Fixes: 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings") Signed-off-by: Chen Wandun Reported-by: Eric Dumazet Cc: Shakeel Butt Cc: Nicholas Piggin Cc: Kefeng Wang Cc: Hanjun Guo Cc: Uladzislau Rezki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d77830ff604c..e8a807c78110 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2816,6 +2816,8 @@ vm_area_alloc_pages(gfp_t gfp, int nid, unsigned int order, unsigned int nr_pages, struct page **pages) { unsigned int nr_allocated = 0; + struct page *page; + int i; /* * For order-0 pages we make use of bulk allocator, if @@ -2823,7 +2825,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid, * to fails, fallback to a single page allocator that is * more permissive. */ - if (!order) { + if (!order && nid != NUMA_NO_NODE) { while (nr_allocated < nr_pages) { unsigned int nr, nr_pages_request; @@ -2848,7 +2850,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid, if (nr != nr_pages_request) break; } - } else + } else if (order) /* * Compound pages required for remap_vmalloc_page if * high-order pages. @@ -2856,11 +2858,12 @@ vm_area_alloc_pages(gfp_t gfp, int nid, gfp |= __GFP_COMP; /* High-order pages or fallback path if "bulk" fails. */ - while (nr_allocated < nr_pages) { - struct page *page; - int i; - page = alloc_pages_node(nid, gfp, order); + while (nr_allocated < nr_pages) { + if (nid == NUMA_NO_NODE) + page = alloc_pages(gfp, order); + else + page = alloc_pages_node(nid, gfp, order); if (unlikely(!page)) break;