diff mbox series

mm: mmu_gather: do not expose delayed_rmap flag

Message ID Y3SWCu6NRaMQ5dbD@li-4a3a4a4c-28e5-11b2-a85c-a8d192c6f089.ibm.com
State New
Headers
Series mm: mmu_gather: do not expose delayed_rmap flag |

Commit Message

Alexander Gordeev Nov. 16, 2022, 7:49 a.m. UTC 
  Flag delayed_rmap of 'struct mmu_gather' is rather
a private member, but it is still accessed directly.
Instead, let the TLB gather code access the flag.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
---
 mm/memory.c     | 3 +--
 mm/mmu_gather.c | 3 +++
 2 files changed, 4 insertions(+), 2 deletions(-)

Comments

Linus Torvalds Nov. 16, 2022, 5:45 p.m. UTC | #1 
On Tue, Nov 15, 2022 at 11:49 PM Alexander Gordeev
<agordeev@linux.ibm.com> wrote:
>
> Flag delayed_rmap of 'struct mmu_gather' is rather
> a private member, but it is still accessed directly.
> Instead, let the TLB gather code access the flag.

Now, I set it up so that if you don't use delayed_rmap, the
tlb_flush_rmaps() function ends up being an empty inline function, and
as such the compiler should already have done this for you - including
optimizing out the test that then doesn't even matter.

But this patch shouldn't *matter*, but it also isn't wrong, so..

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>

Thanks,

                    Linus
diff mbox series

Patch

diff --git a/mm/memory.c b/mm/memory.c
index 42f10cc1de58..38b58cd07b52 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1465,8 +1465,7 @@  static unsigned long zap_pte_range(struct mmu_gather *tlb,
 	/* Do the actual TLB flush before dropping ptl */
 	if (force_flush) {
 		tlb_flush_mmu_tlbonly(tlb);
-		if (tlb->delayed_rmap)
-			tlb_flush_rmaps(tlb, vma);
+		tlb_flush_rmaps(tlb, vma);
 	}
 	pte_unmap_unlock(start_pte, ptl);
 
diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c
index 79de59136cd2..9f22309affee 100644
--- a/mm/mmu_gather.c
+++ b/mm/mmu_gather.c
@@ -60,6 +60,9 @@  void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma)
 {
 	struct mmu_gather_batch *batch;
 
+	if (!tlb->delayed_rmap)
+		return;
+
 	batch = tlb->active;
 	for (int i = 0; i < batch->nr; i++) {
 		struct encoded_page *enc = batch->encoded_pages[i];