From: Huang Ying <ying.huang@intel.com> mainline inclusion from mainline-v5.15-rc1 commit f00230ff8411eaecbea1f2e528e205424f3725ba category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IAFONL CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Before commit c5b5a3dd2c1f ("mm: thp: refactor NUMA fault handling"), the TLB flushing is done in do_huge_pmd_numa_page() itself via flush_tlb_range(). But after commit c5b5a3dd2c1f ("mm: thp: refactor NUMA fault handling"), the TLB flushing is done in migrate_pages() as in the following code path anyway. do_huge_pmd_numa_page migrate_misplaced_page migrate_pages So now, the TLB flushing code in do_huge_pmd_numa_page() becomes unnecessary. So the code is deleted in this patch to simplify the code. This is only code cleanup, there's no visible performance difference. The mmu_notifier_invalidate_range() in do_huge_pmd_numa_page() is deleted too. Because migrate_pages() takes care of that too when CPU TLB is flushed. Link: https://lkml.kernel.org/r/20210720065529.716031-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> --- mm/huge_memory.c | 26 -------------------------- 1 file changed, 26 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 72b4f10b822f..eb293d17a104 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1444,32 +1444,6 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) goto out; } - /* - * Since we took the NUMA fault, we must have observed the !accessible - * bit. Make sure all other CPUs agree with that, to avoid them - * modifying the page we're about to migrate. - * - * Must be done under PTL such that we'll observe the relevant - * inc_tlb_flush_pending(). - * - * We are not sure a pending tlb flush here is for a huge page - * mapping or not. Hence use the tlb range variant - */ - if (mm_tlb_flush_pending(vma->vm_mm)) { - flush_tlb_range(vma, haddr, haddr + HPAGE_PMD_SIZE); - /* - * change_huge_pmd() released the pmd lock before - * invalidating the secondary MMUs sharing the primary - * MMU pagetables (with ->invalidate_range()). The - * mmu_notifier_invalidate_range_end() (which - * internally calls ->invalidate_range()) in - * change_pmd_range() will run after us, so we can't - * rely on it here and we need an explicit invalidate. - */ - mmu_notifier_invalidate_range(vma->vm_mm, haddr, - haddr + HPAGE_PMD_SIZE); - } - pmd = pmd_modify(oldpmd, vma->vm_page_prot); page = vm_normal_page_pmd(vma, haddr, pmd); if (!page) -- 2.25.1