[PATCH V2 fix 5/6] mm: hugetlb: add a new function to allocate a new gigantic page
From: Huang Shijie <hidden>
Date: 2016-11-16 06:55:54
Also in:
linux-mm
Subsystem:
hugetlb subsystem, memory management, the rest · Maintainers:
Muchun Song, Oscar Salvador, Andrew Morton, Linus Torvalds
There are three ways we can allocate a new gigantic page: 1. When the NUMA is not enabled, use alloc_gigantic_page() to get the gigantic page. 2. The NUMA is enabled, but the vma is NULL. There is no memory policy we can refer to. So create a @nodes_allowed, initialize it with init_nodemask_of_mempolicy() or init_nodemask_of_node(). Then use alloc_fresh_gigantic_page() to get the gigantic page. 3. The NUMA is enabled, and the vma is valid. We can follow the memory policy of the @vma. Get @nodes_allowed by huge_nodemask(), and use alloc_fresh_gigantic_page() to get the gigantic page. Signed-off-by: Huang Shijie <redacted> --- Since the huge_nodemask() is changed, we have to change this function a little. --- mm/hugetlb.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6995087..c33bddc 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c@@ -1502,6 +1502,69 @@ int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) /* * There are 3 ways this can get called: + * + * 1. When the NUMA is not enabled, use alloc_gigantic_page() to get + * the gigantic page. + * + * 2. The NUMA is enabled, but the vma is NULL. + * Create a @nodes_allowed, and use alloc_fresh_gigantic_page() to get + * the gigantic page. + * + * 3. The NUMA is enabled, and the vma is valid. + * Use the @vma's memory policy. + * Get @nodes_allowed by huge_nodemask(), and use alloc_fresh_gigantic_page() + * to get the gigantic page. + */ +static struct page *__hugetlb_alloc_gigantic_page(struct hstate *h, + struct vm_area_struct *vma, unsigned long addr, int nid) +{ + NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY); + struct page *page = NULL; + + /* Not NUMA */ + if (!IS_ENABLED(CONFIG_NUMA)) { + if (nid == NUMA_NO_NODE) + nid = numa_mem_id(); + + page = alloc_gigantic_page(nid, huge_page_order(h)); + if (page) + prep_compound_gigantic_page(page, huge_page_order(h)); + + NODEMASK_FREE(nodes_allowed); + return page; + } + + /* NUMA && !vma */ + if (!vma) { + if (nid == NUMA_NO_NODE) { + if (!init_nodemask_of_mempolicy(nodes_allowed)) { + NODEMASK_FREE(nodes_allowed); + nodes_allowed = &node_states[N_MEMORY]; + } + } else if (nodes_allowed) { + init_nodemask_of_node(nodes_allowed, nid); + } else { + nodes_allowed = &node_states[N_MEMORY]; + } + + page = alloc_fresh_gigantic_page(h, nodes_allowed, true); + + if (nodes_allowed != &node_states[N_MEMORY]) + NODEMASK_FREE(nodes_allowed); + + return page; + } + + /* NUMA && vma */ + if (huge_nodemask(vma, addr, nodes_allowed)) + page = alloc_fresh_gigantic_page(h, nodes_allowed, true); + + NODEMASK_FREE(nodes_allowed); + return page; +} + +/* + * There are 3 ways this can get called: * 1. With vma+addr: we use the VMA's memory policy * 2. With !vma, but nid=NUMA_NO_NODE: We try to allocate a huge * page from any node, and let the buddy allocator itself figure
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2.5.5