From 6c855fce2e62e5e9b796b23fe15be1d8b2c8bee2 Mon Sep 17 00:00:00 2001 From: Hugh Dickins <hughd@google.com> Date: Wed, 7 Jul 2021 13:13:33 -0700 Subject: [PATCH] mm/rmap: try_to_migrate() skip zone_device !device_private I know nothing about zone_device pages and !device_private pages; but if try_to_migrate_one() will do nothing for them, then it's better that try_to_migrate() filter them first, than trawl through all their vmas. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Link: https://lore.kernel.org/lkml/1241d356-8ec9-f47b-a5ec-9b2bf66d242@google.com/ Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Yang Shi <shy828301@gmail.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- mm/rmap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index 1235368f06282..795f9d5f83863 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1703,9 +1703,6 @@ static bool try_to_migrate_one(struct page *page, struct vm_area_struct *vma, struct mmu_notifier_range range; enum ttu_flags flags = (enum ttu_flags)(long)arg; - if (is_zone_device_page(page) && !is_device_private_page(page)) - return true; - /* * When racing against e.g. zap_pte_range() on another cpu, * in between its ptep_get_and_clear_full() and page_remove_rmap(), @@ -1944,6 +1941,9 @@ void try_to_migrate(struct page *page, enum ttu_flags flags) TTU_SYNC))) return; + if (is_zone_device_page(page) && !is_device_private_page(page)) + return; + /* * During exec, a temporary VMA is setup and later moved. * The VMA is moved under the anon_vma lock but not the -- GitLab