linux-kernel - [PATCH v2 5/5] mm: Add update_mmu_tlb

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Message-Id: <20240506155120.83105-6-libang.li@antgroup.com>
Date: Mon, 06 May 2024 23:51:20 +0800
From: "Bang Li" <libang.li@...group.com>
To: akpm@...ux-foundation.org,
	chenhuacai@...nel.org,
	tsbogend@...ha.franken.de,
	paul.walmsley@...ive.com,
	palmer@...belt.com,
	chris@...kel.net,
	jcmvbkbc@...il.com
Cc:  <linux-kernel@...r.kernel.org>,
   <linux-mm@...ck.org>,
   <loongarch@...ts.linux.dev>,
   <linux-riscv@...ts.infradead.org>,
   <david@...hat.com>,
   <ryan.roberts@....com>,
   <ioworker0@...il.com>,
   <libang.linux@...il.com>,
  "Bang Li" <libang.li@...group.com>
Subject: [PATCH v2 5/5] mm: Add update_mmu_tlb_range()

After the commit 19eaf44954df ("mm: thp: support allocation of anonymous
multi-size THP"), it may need to batch update tlb of an address range
through the update_mmu_tlb function. We can simplify this operation by
adding the update_mmu_tlb_range function, which may also reduce the
execution of some unnecessary code in some architectures.

Signed-off-by: Bang Li <libang.li@...group.com>
---
 include/linux/pgtable.h | 8 ++++++++
 mm/memory.c             | 4 +---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 18019f037bae..869bfe6054f1 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -737,6 +737,14 @@ static inline void update_mmu_tlb(struct vm_area_struct *vma,
 #define __HAVE_ARCH_UPDATE_MMU_TLB
 #endif
 
+#ifndef __HAVE_ARCH_UPDATE_MMU_TLB_RANGE
+static inline void update_mmu_tlb_range(struct vm_area_struct *vma,
+				unsigned long address, pte_t *ptep, unsigned int nr)
+{
+}
+#define __HAVE_ARCH_UPDATE_MMU_TLB_RANGE
+#endif
+
 /*
  * Some architectures may be able to avoid expensive synchronization
  * primitives when modifications are made to PTE's which are already
diff --git a/mm/memory.c b/mm/memory.c
index eea6e4984eae..2d53e29cf76e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4421,7 +4421,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	vm_fault_t ret = 0;
 	int nr_pages = 1;
 	pte_t entry;
-	int i;
 
 	/* File mapping without ->vm_ops ? */
 	if (vma->vm_flags & VM_SHARED)
@@ -4491,8 +4490,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 		update_mmu_tlb(vma, addr, vmf->pte);
 		goto release;
 	} else if (nr_pages > 1 && !pte_range_none(vmf->pte, nr_pages)) {
-		for (i = 0; i < nr_pages; i++)
-			update_mmu_tlb(vma, addr + PAGE_SIZE * i, vmf->pte + i);
+		update_mmu_tlb_range(vma, addr, vmf->pte, nr_pages);
 		goto release;
 	}
 
-- 
2.19.1.6.gb485710b