linux-kernel - mm: mmu_gather: do not expose delayed

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Date:   Wed, 16 Nov 2022 08:49:30 +0100
From:   Alexander Gordeev <agordeev@...ux.ibm.com>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Hugh Dickins <hughd@...gle.com>,
        Johannes Weiner <hannes@...xchg.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Nadav Amit <nadav.amit@...il.com>,
        Will Deacon <will@...nel.org>,
        Aneesh Kumar <aneesh.kumar@...ux.ibm.com>,
        Nick Piggin <npiggin@...il.com>,
        Heiko Carstens <hca@...ux.ibm.com>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ux.ibm.com>,
        Sven Schnelle <svens@...ux.ibm.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Gerald Schaefer <gerald.schaefer@...ux.ibm.com>
Subject: mm: mmu_gather: do not expose delayed_rmap flag

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@...ux.ibm.com>
---
 mm/memory.c     | 3 +--
 mm/mmu_gather.c | 3 +++
 2 files changed, 4 insertions(+), 2 deletions(-)

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];
-- 
2.31.1