linux-kernel - [PATCH v2 29/30] mm: Convert do_set_pte() to set_pte

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Message-Id: <20230227175741.71216-30-willy@infradead.org>
Date:   Mon, 27 Feb 2023 17:57:40 +0000
From:   "Matthew Wilcox (Oracle)" <willy@...radead.org>
To:     linux-mm@...ck.org, linux-arch@...r.kernel.org
Cc:     Yin Fengwei <fengwei.yin@...el.com>, linux-kernel@...r.kernel.org,
        Matthew Wilcox <willy@...radead.org>
Subject: [PATCH v2 29/30] mm: Convert do_set_pte() to set_pte_range()

From: Yin Fengwei <fengwei.yin@...el.com>

set_pte_range() allows to setup page table entries for a specific
range.  It takes advantage of batched rmap update for large folio.
It now takes care of calling update_mmu_cache_range().

Signed-off-by: Yin Fengwei <fengwei.yin@...el.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
 Documentation/filesystems/locking.rst |  2 +-
 include/linux/mm.h                    |  3 ++-
 mm/filemap.c                          |  3 +--
 mm/memory.c                           | 27 +++++++++++++++------------
 4 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
index 7de7a7272a5e..922886fefb7f 100644
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -663,7 +663,7 @@ locked. The VM will unlock the page.
 Filesystem should find and map pages associated with offsets from "start_pgoff"
 till "end_pgoff". ->map_pages() is called with page table locked and must
 not block.  If it's not possible to reach a page without blocking,
-filesystem should skip it. Filesystem should use do_set_pte() to setup
+filesystem should skip it. Filesystem should use set_pte_range() to setup
 page table entry. Pointer to entry associated with the page is passed in
 "pte" field in vm_fault structure. Pointers to entries for other offsets
 should be calculated relative to "pte".
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1f79667824eb..568ebe7058d4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1168,7 +1168,8 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
 }
 
 vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page);
-void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr);
+void set_pte_range(struct vm_fault *vmf, struct folio *folio,
+		struct page *page, unsigned int nr, unsigned long addr);
 
 vm_fault_t finish_fault(struct vm_fault *vmf);
 vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);
diff --git a/mm/filemap.c b/mm/filemap.c
index db86e459dde6..07ebd90967a3 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3507,8 +3507,7 @@ static vm_fault_t filemap_map_folio_range(struct vm_fault *vmf,
 			ret = VM_FAULT_NOPAGE;
 
 		ref_count++;
-		do_set_pte(vmf, page, addr);
-		update_mmu_cache(vma, addr, vmf->pte);
+		set_pte_range(vmf, folio, page, 1, addr);
 	} while (vmf->pte++, page++, addr += PAGE_SIZE, ++count < nr_pages);
 
 	/* Restore the vmf->pte */
diff --git a/mm/memory.c b/mm/memory.c
index bfa3100ec5a3..b09c03e4fadb 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4256,7 +4256,8 @@ vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
 }
 #endif
 
-void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr)
+void set_pte_range(struct vm_fault *vmf, struct folio *folio,
+		struct page *page, unsigned int nr, unsigned long addr)
 {
 	struct vm_area_struct *vma = vmf->vma;
 	bool uffd_wp = pte_marker_uffd_wp(vmf->orig_pte);
@@ -4264,7 +4265,7 @@ void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr)
 	bool prefault = vmf->address != addr;
 	pte_t entry;
 
-	flush_icache_page(vma, page);
+	flush_icache_pages(vma, page, nr);
 	entry = mk_pte(page, vma->vm_page_prot);
 
 	if (prefault && arch_wants_old_prefaulted_pte())
@@ -4278,14 +4279,18 @@ void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr)
 		entry = pte_mkuffd_wp(entry);
 	/* copy-on-write page */
 	if (write && !(vma->vm_flags & VM_SHARED)) {
-		inc_mm_counter(vma->vm_mm, MM_ANONPAGES);
-		page_add_new_anon_rmap(page, vma, addr);
-		lru_cache_add_inactive_or_unevictable(page, vma);
+		add_mm_counter(vma->vm_mm, MM_ANONPAGES, nr);
+		VM_BUG_ON_FOLIO(nr != 1, folio);
+		folio_add_new_anon_rmap(folio, vma, addr);
+		folio_add_lru_vma(folio, vma);
 	} else {
-		inc_mm_counter(vma->vm_mm, mm_counter_file(page));
-		page_add_file_rmap(page, vma, false);
+		add_mm_counter(vma->vm_mm, mm_counter_file(page), nr);
+		folio_add_file_rmap_range(folio, page, nr, vma, false);
 	}
-	set_pte_at(vma->vm_mm, addr, vmf->pte, entry);
+	set_ptes(vma->vm_mm, addr, vmf->pte, entry, nr);
+
+	/* no need to invalidate: a not-present page won't be cached */
+	update_mmu_cache_range(vma, addr, vmf->pte, nr);
 }
 
 static bool vmf_pte_changed(struct vm_fault *vmf)
@@ -4358,11 +4363,9 @@ vm_fault_t finish_fault(struct vm_fault *vmf)
 
 	/* Re-check under ptl */
 	if (likely(!vmf_pte_changed(vmf))) {
-		do_set_pte(vmf, page, vmf->address);
-
-		/* no need to invalidate: a not-present page won't be cached */
-		update_mmu_cache(vma, vmf->address, vmf->pte);
+		struct folio *folio = page_folio(page);
 
+		set_pte_range(vmf, folio, page, 1, vmf->address);
 		ret = 0;
 	} else {
 		update_mmu_tlb(vma, vmf->address, vmf->pte);
-- 
2.39.1