diff options
| author |   Huang Ying <ying.huang@intel.com> | 2021-09-02 14:56:40 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-03 09:58:13 -0700 |
| commit | f00230ff8411eaecbea1f2e528e205424f3725ba (patch) | |
| tree | 8856c555738debfe98181598279a960fe7ec764b /mm/huge_memory.c | |
| parent | mm: remove flush_kernel_dcache_page (diff) | |
| download | linux-dev-f00230ff8411eaecbea1f2e528e205424f3725ba.tar.xz linux-dev-f00230ff8411eaecbea1f2e528e205424f3725ba.zip | |
mm,do_huge_pmd_numa_page: remove unnecessary TLB flushing code
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>
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 26 |
1 files changed, 0 insertions, 26 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 890fb73ac89b..5e9ef0fc261e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1440,32 +1440,6 @@ 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) |