diff mbox series

[RFC,08/24] mm/memory: allow specifying MM lock range to handle_mm_fault()

Message ID 20200224203057.162467-9-walken@google.com (mailing list archive)
State New, archived
Headers show
Series Fine grained MM locking | expand

Commit Message

Michel Lespinasse Feb. 24, 2020, 8:30 p.m. UTC
This change adds a new handle_mm_fault_range() function, which behaves
like handle_mm_fault() but specifies an explicit MM lock range.

handle_mm_fault() remains as an inline wrapper which passes the default
coarse locking range.

Signed-off-by: Michel Lespinasse <walken@google.com>
---
 include/linux/hugetlb.h |  5 +++--
 include/linux/mm.h      | 11 +++++++++--
 mm/hugetlb.c            | 14 +++++++++-----
 mm/memory.c             | 16 +++++++++-------
 4 files changed, 30 insertions(+), 16 deletions(-)
diff mbox series

Patch

diff --git include/linux/hugetlb.h include/linux/hugetlb.h
index 31d4920994b9..75992d78289e 100644
--- include/linux/hugetlb.h
+++ include/linux/hugetlb.h
@@ -88,7 +88,8 @@  int hugetlb_report_node_meminfo(int, char *);
 void hugetlb_show_meminfo(void);
 unsigned long hugetlb_total_pages(void);
 vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
-			unsigned long address, unsigned int flags);
+			unsigned long address, unsigned int flags,
+			struct mm_lock_range *range);
 int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
 				struct vm_area_struct *dst_vma,
 				unsigned long dst_addr,
@@ -307,7 +308,7 @@  static inline void __unmap_hugepage_range(struct mmu_gather *tlb,
 
 static inline vm_fault_t hugetlb_fault(struct mm_struct *mm,
 			struct vm_area_struct *vma, unsigned long address,
-			unsigned int flags)
+			unsigned int flags, struct mm_lock_range *range)
 {
 	BUG();
 	return 0;
diff --git include/linux/mm.h include/linux/mm.h
index a1c9a0aa898b..1b6b022064b4 100644
--- include/linux/mm.h
+++ include/linux/mm.h
@@ -1460,8 +1460,15 @@  int generic_error_remove_page(struct address_space *mapping, struct page *page);
 int invalidate_inode_page(struct page *page);
 
 #ifdef CONFIG_MMU
-extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
-			unsigned long address, unsigned int flags);
+extern vm_fault_t handle_mm_fault_range(struct vm_area_struct *vma,
+			unsigned long address, unsigned int flags,
+			struct mm_lock_range *range);
+static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
+			unsigned long address, unsigned int flags)
+{
+	return handle_mm_fault_range(vma, address, flags,
+				     mm_coarse_lock_range());
+}
 extern int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
 			    unsigned long address, unsigned int fault_flags,
 			    bool *unlocked);
diff --git mm/hugetlb.c mm/hugetlb.c
index 662f34b6c869..9d6fe9f291a7 100644
--- mm/hugetlb.c
+++ mm/hugetlb.c
@@ -3788,7 +3788,8 @@  int huge_add_to_page_cache(struct page *page, struct address_space *mapping,
 static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
 			struct vm_area_struct *vma,
 			struct address_space *mapping, pgoff_t idx,
-			unsigned long address, pte_t *ptep, unsigned int flags)
+			unsigned long address, pte_t *ptep, unsigned int flags,
+			struct mm_lock_range *range)
 {
 	struct hstate *h = hstate_vma(vma);
 	vm_fault_t ret = VM_FAULT_SIGBUS;
@@ -3831,7 +3832,7 @@  static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
 				.vma = vma,
 				.address = haddr,
 				.flags = flags,
-				.range = mm_coarse_lock_range(),
+				.range = range,
 				/*
 				 * Hard to debug if it ends up being
 				 * used by a callee that assumes
@@ -3997,7 +3998,8 @@  u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx)
 #endif
 
 vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
-			unsigned long address, unsigned int flags)
+			unsigned long address, unsigned int flags,
+			struct mm_lock_range *range)
 {
 	pte_t *ptep, entry;
 	spinlock_t *ptl;
@@ -4039,7 +4041,8 @@  vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 
 	entry = huge_ptep_get(ptep);
 	if (huge_pte_none(entry)) {
-		ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, flags);
+		ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep,
+				      flags, range);
 		goto out_mutex;
 	}
 
@@ -4348,7 +4351,8 @@  long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 						FAULT_FLAG_ALLOW_RETRY);
 				fault_flags |= FAULT_FLAG_TRIED;
 			}
-			ret = hugetlb_fault(mm, vma, vaddr, fault_flags);
+			ret = hugetlb_fault(mm, vma, vaddr, fault_flags,
+					    mm_coarse_lock_range());
 			if (ret & VM_FAULT_ERROR) {
 				err = vm_fault_to_errno(ret, flags);
 				remainder = 0;
diff --git mm/memory.c mm/memory.c
index 6cb3359f0857..bc24a6bdaa06 100644
--- mm/memory.c
+++ mm/memory.c
@@ -4039,7 +4039,8 @@  static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
  * return value.  See filemap_fault() and __lock_page_or_retry().
  */
 static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
-		unsigned long address, unsigned int flags)
+		unsigned long address, unsigned int flags,
+		struct mm_lock_range *range)
 {
 	struct vm_fault vmf = {
 		.vma = vma,
@@ -4047,7 +4048,7 @@  static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
 		.flags = flags,
 		.pgoff = linear_page_index(vma, address),
 		.gfp_mask = __get_fault_gfp_mask(vma),
-		.range = mm_coarse_lock_range(),
+		.range = range,
 	};
 	unsigned int dirty = flags & FAULT_FLAG_WRITE;
 	struct mm_struct *mm = vma->vm_mm;
@@ -4134,8 +4135,9 @@  static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
  * The mmap_sem may have been released depending on flags and our
  * return value.  See filemap_fault() and __lock_page_or_retry().
  */
-vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
-		unsigned int flags)
+vm_fault_t handle_mm_fault_range(struct vm_area_struct *vma,
+		unsigned long address, unsigned int flags,
+		struct mm_lock_range *range)
 {
 	vm_fault_t ret;
 
@@ -4160,9 +4162,9 @@  vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
 		mem_cgroup_enter_user_fault();
 
 	if (unlikely(is_vm_hugetlb_page(vma)))
-		ret = hugetlb_fault(vma->vm_mm, vma, address, flags);
+		ret = hugetlb_fault(vma->vm_mm, vma, address, flags, range);
 	else
-		ret = __handle_mm_fault(vma, address, flags);
+		ret = __handle_mm_fault(vma, address, flags, range);
 
 	if (flags & FAULT_FLAG_USER) {
 		mem_cgroup_exit_user_fault();
@@ -4178,7 +4180,7 @@  vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(handle_mm_fault);
+EXPORT_SYMBOL_GPL(handle_mm_fault_range);
 
 #ifndef __PAGETABLE_P4D_FOLDED
 /*