From 394e31d2ceb4b9eae25bd9ed8ea8cb19a40ff181 Mon Sep 17 00:00:00 2001 From: Xishi Qiu Date: Thu, 28 Jul 2016 15:48:53 -0700 Subject: [PATCH] mem-hotplug: alloc new page from a nearest neighbor node when mem-offline If we offline a node, alloc the new page from a nearest neighbor node instead of the current node or other remote nodes, because re-migrate is a waste of time and the distance of the remote nodes is often very large. Also use GFP_HIGHUSER_MOVABLE to alloc new page if the zone is movable zone or highmem zone. Link: http://lkml.kernel.org/r/5795E18B.5060302@huawei.com Signed-off-by: Xishi Qiu Cc: Joonsoo Kim Cc: Vlastimil Babka Cc: Naoya Horiguchi Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory_hotplug.c | 38 +++++++++++++++++++++++++++++++++----- 1 file changed, 33 insertions(+), 5 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 065140ecd081..3894b65b1555 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1548,6 +1548,37 @@ static unsigned long scan_movable_pages(unsigned long start, unsigned long end) return 0; } +static struct page *new_node_page(struct page *page, unsigned long private, + int **result) +{ + gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE; + int nid = page_to_nid(page); + nodemask_t nmask = node_online_map; + struct page *new_page; + + /* + * TODO: allocate a destination hugepage from a nearest neighbor node, + * accordance with memory policy of the user process if possible. For + * now as a simple work-around, we use the next node for destination. + */ + if (PageHuge(page)) + return alloc_huge_page_node(page_hstate(compound_head(page)), + next_node_in(nid, nmask)); + + node_clear(nid, nmask); + if (PageHighMem(page) + || (zone_idx(page_zone(page)) == ZONE_MOVABLE)) + gfp_mask |= __GFP_HIGHMEM; + + new_page = __alloc_pages_nodemask(gfp_mask, 0, + node_zonelist(nid, gfp_mask), &nmask); + if (!new_page) + new_page = __alloc_pages(gfp_mask, 0, + node_zonelist(nid, gfp_mask)); + + return new_page; +} + #define NR_OFFLINE_AT_ONCE_PAGES (256) static int do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) @@ -1611,11 +1642,8 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) goto out; } - /* - * alloc_migrate_target should be improooooved!! - * migrate_pages returns # of failed pages. - */ - ret = migrate_pages(&source, alloc_migrate_target, NULL, 0, + /* Allocate a new page from the nearest neighbor node */ + ret = migrate_pages(&source, new_node_page, NULL, 0, MIGRATE_SYNC, MR_MEMORY_HOTPLUG); if (ret) putback_movable_pages(&source); -- 2.11.0