diff options
| author | Roman Gushchin <roman.gushchin@linux.dev> | 2025-05-22 01:28:38 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-05-31 22:46:12 -0700 |
| commit | bfe125f1b1870c7b5f05b489a525042d6715fcc1 (patch) | |
| tree | 36c1847a303850e9a59a605683438bd1de6d37f9 /mm | |
| parent | 28615e6eed152f2fda5486680090b74aeed7b554 (diff) | |
mmu_gather: move tlb flush for VM_PFNMAP/VM_MIXEDMAP vmas into free_pgtables()
Commit b67fbebd4cf9 ("mmu_gather: Force tlb-flush VM_PFNMAP vmas") added a
forced tlbflush to tlb_vma_end(), which is required to avoid a race
between munmap() and unmap_mapping_range(). However it added some
overhead to other paths where tlb_vma_end() is used, but vmas are not
removed, e.g. madvise(MADV_DONTNEED).
Fix this by moving the tlb flush out of tlb_end_vma() into new
tlb_flush_vmas() called from free_pgtables(), somewhat similar to the
stable version of the original commit: commit 895428ee124a ("mm: Force TLB
flush for PFNMAP mappings before unlink_file_vma()").
Note, that if tlb->fullmm is set, no flush is required, as the whole mm is
about to be destroyed.
Link: https://lkml.kernel.org/r/20250522012838.163876-1-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Nick Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 2 | ||||
| -rw-r--r-- | mm/mmu_gather.c | 1 |
2 files changed, 3 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index 37d8738f5e12..8eba595056fe 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -358,6 +358,8 @@ void free_pgtables(struct mmu_gather *tlb, struct ma_state *mas, { struct unlink_vma_file_batch vb; + tlb_free_vmas(tlb); + do { unsigned long addr = vma->vm_start; struct vm_area_struct *next; diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c index db7ba4a725d6..b49cc6385f1f 100644 --- a/mm/mmu_gather.c +++ b/mm/mmu_gather.c @@ -424,6 +424,7 @@ static void __tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, #ifdef CONFIG_MMU_GATHER_PAGE_SIZE tlb->page_size = 0; #endif + tlb->vma_pfn = 0; __tlb_reset_range(tlb); inc_tlb_flush_pending(tlb->mm); |