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authorMichal Hocko <mhocko@suse.com>2017-07-10 15:48:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-10 16:32:31 -0700
commit4db9b2efe94967be34e3b136a93251a3c1736dd5 (patch)
treebff61c2620df913698bf2617ce6acb293e3fe817 /include
parent7f252f277b66854c61d3abdd4c196d6dc64fa333 (diff)
hugetlb, memory_hotplug: prefer to use reserved pages for migration
new_node_page will try to use the origin's next NUMA node as the migration destination for hugetlb pages. If such a node doesn't have any preallocated pool it falls back to __alloc_buddy_huge_page_no_mpol to allocate a surplus page instead. This is quite subotpimal for any configuration when hugetlb pages are no distributed to all NUMA nodes evenly. Say we have a hotplugable node 4 and spare hugetlb pages are node 0 /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages:10000 /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node2/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node3/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node4/hugepages/hugepages-2048kB/nr_hugepages:10000 /sys/devices/system/node/node5/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node6/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node7/hugepages/hugepages-2048kB/nr_hugepages:0 Now we consume the whole pool on node 4 and try to offline this node. All the allocated pages should be moved to node0 which has enough preallocated pages to hold them. With the current implementation offlining very likely fails because hugetlb allocations during runtime are much less reliable. Fix this by reusing the nodemask which excludes migration source and try to find a first node which has a page in the preallocated pool first and fall back to __alloc_buddy_huge_page_no_mpol only when the whole pool is consumed. [akpm@linux-foundation.org: remove bogus arg from alloc_huge_page_nodemask() stub] Link: http://lkml.kernel.org/r/20170608074553.22152-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: zhong jiang <zhongjiang@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/hugetlb.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 57f700ac127e..8fd0725d3f30 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -349,6 +349,7 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
struct page *alloc_huge_page_node(struct hstate *h, int nid);
struct page *alloc_huge_page_noerr(struct vm_area_struct *vma,
unsigned long addr, int avoid_reserve);
+struct page *alloc_huge_page_nodemask(struct hstate *h, const nodemask_t *nmask);
int huge_add_to_page_cache(struct page *page, struct address_space *mapping,
pgoff_t idx);
@@ -524,6 +525,7 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr
struct hstate {};
#define alloc_huge_page(v, a, r) NULL
#define alloc_huge_page_node(h, nid) NULL
+#define alloc_huge_page_nodemask(h, nmask) NULL
#define alloc_huge_page_noerr(v, a, r) NULL
#define alloc_bootmem_huge_page(h) NULL
#define hstate_file(f) NULL