diff mbox series

[v11,3/4] mm/tlbbatch: Introduce arch_flush_tlb_batched_pending()

Message ID 20230717131004.12662-4-yangyicong@huawei.com (mailing list archive)
State New
Headers show
Series arm64: support batched/deferred tlb shootdown during page reclamation/migration | expand

Commit Message

Yicong Yang July 17, 2023, 1:10 p.m. UTC 
From: Yicong Yang <yangyicong@hisilicon.com>

Currently we'll flush the mm in flush_tlb_batched_pending() to
avoid race between reclaim unmaps pages by batched TLB flush
and mprotect/munmap/etc. Other architectures like arm64 may
only need a synchronization barrier(dsb) here rather than
a full mm flush. So add arch_flush_tlb_batched_pending() to
allow an arch-specific implementation here. This intends no
functional changes on x86 since still a full mm flush for
x86.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
---
 arch/x86/include/asm/tlbflush.h | 5 +++++
 mm/rmap.c                       | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

Comments

Catalin Marinas July 21, 2023, 6:24 p.m. UTC | #1 
On Mon, Jul 17, 2023 at 09:10:03PM +0800, Yicong Yang wrote:
> From: Yicong Yang <yangyicong@hisilicon.com>
> 
> Currently we'll flush the mm in flush_tlb_batched_pending() to
> avoid race between reclaim unmaps pages by batched TLB flush
> and mprotect/munmap/etc. Other architectures like arm64 may
> only need a synchronization barrier(dsb) here rather than
> a full mm flush. So add arch_flush_tlb_batched_pending() to
> allow an arch-specific implementation here. This intends no
> functional changes on x86 since still a full mm flush for
> x86.
> 
> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
diff mbox series

Patch

diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 1c7d3a36e16c..837e4a50281a 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -284,6 +284,11 @@  static inline void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *b
 	cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm));
 }
 
+static inline void arch_flush_tlb_batched_pending(struct mm_struct *mm)
+{
+	flush_tlb_mm(mm);
+}
+
 extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch);
 
 static inline bool pte_flags_need_flush(unsigned long oldflags,
diff --git a/mm/rmap.c b/mm/rmap.c
index 9699c6011b0e..3a16c91be7e2 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -717,7 +717,7 @@  void flush_tlb_batched_pending(struct mm_struct *mm)
 	int flushed = batch >> TLB_FLUSH_BATCH_FLUSHED_SHIFT;
 
 	if (pending != flushed) {
-		flush_tlb_mm(mm);
+		arch_flush_tlb_batched_pending(mm);
 		/*
 		 * If the new TLB flushing is pending during flushing, leave
 		 * mm->tlb_flush_batched as is, to avoid losing flushing.