From c77c5cbafe549eb330e8909861a3e16cbda2c848 Mon Sep 17 00:00:00 2001 From: Yang Shi Date: Mon, 14 Dec 2020 19:13:09 -0800 Subject: mm: migrate: skip shared exec THP for NUMA balancing The NUMA balancing skip shared exec base page. Since CONFIG_READ_ONLY_THP_FOR_FS was introduced, there are probably shared exec THP, so skip such THPs for NUMA balancing as well. And Willy's regular filesystem THP support patches could create shared exec THP wven without that config. In addition, the page_is_file_lru() is used to tell if the page is file cache or not, but it filters out shmem page. It sounds like a typical usecase by putting executables in shmem to achieve performance gain via using shmem-THP, so it sounds worth skipping migration for such case too. Link: https://lkml.kernel.org/r/20201113205359.556831-4-shy828301@gmail.com Signed-off-by: Yang Shi Cc: Matthew Wilcox Cc: Jan Kara Cc: Mel Gorman Cc: Michal Hocko Cc: Song Liu Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/migrate.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'mm/migrate.c') diff --git a/mm/migrate.c b/mm/migrate.c index 47aa50d263c2..a7ccda55ca82 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2071,6 +2071,17 @@ bool pmd_trans_migrating(pmd_t pmd) return PageLocked(page); } +static inline bool is_shared_exec_page(struct vm_area_struct *vma, + struct page *page) +{ + if (page_mapcount(page) != 1 && + (page_is_file_lru(page) || vma_is_shmem(vma)) && + (vma->vm_flags & VM_EXEC)) + return true; + + return false; +} + /* * Attempt to migrate a misplaced page to the specified destination * node. Caller is expected to have an elevated reference count on @@ -2088,8 +2099,7 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, * Don't migrate file pages that are mapped in multiple processes * with execute permissions as they are probably shared libraries. */ - if (page_mapcount(page) != 1 && page_is_file_lru(page) && - (vma->vm_flags & VM_EXEC)) + if (is_shared_exec_page(vma, page)) goto out; /* @@ -2144,6 +2154,9 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, int page_lru = page_is_file_lru(page); unsigned long start = address & HPAGE_PMD_MASK; + if (is_shared_exec_page(vma, page)) + goto out; + new_page = alloc_pages_node(node, (GFP_TRANSHUGE_LIGHT | __GFP_THISNODE), HPAGE_PMD_ORDER); @@ -2255,6 +2268,7 @@ out_fail: out_unlock: unlock_page(page); +out: put_page(page); return 0; } -- cgit v1.2.3