Merge branch 'vm-cleanups' (unmap_vma() interface cleanup)

This series sanitizes the interface to unmap_vma().  The crazy interface
annoyed me no end when I was looking at unmap_single_vma(), which we can
spend quite a lot of time in (especially with loads that have a lot of
small fork/exec's: shell scripts etc).

Moving the nr_accounted calculations to where they belong at least
clarifies things a little.  I hope to come back to look at the
performance of this later, but if/when I get back to it I at least don't
have to see the crazy interfaces any more.

* vm-cleanups:
  vm: remove 'nr_accounted' calculations from the unmap_vmas() interfaces
  vm: simplify unmap_vmas() calling convention

include/linux/mm.h

@@ -896,10 +896,8 @@ int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
 		unsigned long size);
 void zap_page_range(struct vm_area_struct *vma, unsigned long address,
 		unsigned long size, struct zap_details *);
-void unmap_vmas(struct mmu_gather *tlb,
-		struct vm_area_struct *start_vma, unsigned long start_addr,
-		unsigned long end_addr, unsigned long *nr_accounted,
-		struct zap_details *);
+void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
+		unsigned long start, unsigned long end);
 
 /**
  * mm_walk - callbacks for walk_page_range

mm/memory.c

@@ -1295,7 +1295,7 @@ static void unmap_page_range(struct mmu_gather *tlb,
 
 static void unmap_single_vma(struct mmu_gather *tlb,
 		struct vm_area_struct *vma, unsigned long start_addr,
-		unsigned long end_addr, unsigned long *nr_accounted,
+		unsigned long end_addr,
 		struct zap_details *details)
 {
 	unsigned long start = max(vma->vm_start, start_addr);
@@ -1307,9 +1307,6 @@ static void unmap_single_vma(struct mmu_gather *tlb,
 	if (end <= vma->vm_start)
 		return;
 
-	if (vma->vm_flags & VM_ACCOUNT)
-		*nr_accounted += (end - start) >> PAGE_SHIFT;
-
 	if (unlikely(is_pfn_mapping(vma)))
 		untrack_pfn_vma(vma, 0, 0);
 
@@ -1339,8 +1336,6 @@ static void unmap_single_vma(struct mmu_gather *tlb,
  * @vma: the starting vma
  * @start_addr: virtual address at which to start unmapping
  * @end_addr: virtual address at which to end unmapping
- * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
- * @details: details of nonlinear truncation or shared cache invalidation
  *
  * Unmap all pages in the vma list.
  *
@@ -1355,15 +1350,13 @@ static void unmap_single_vma(struct mmu_gather *tlb,
  */
 void unmap_vmas(struct mmu_gather *tlb,
 		struct vm_area_struct *vma, unsigned long start_addr,
-		unsigned long end_addr, unsigned long *nr_accounted,
-		struct zap_details *details)
+		unsigned long end_addr)
 {
 	struct mm_struct *mm = vma->vm_mm;
 
 	mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);
 	for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next)
-		unmap_single_vma(tlb, vma, start_addr, end_addr, nr_accounted,
-				 details);
+		unmap_single_vma(tlb, vma, start_addr, end_addr, NULL);
 	mmu_notifier_invalidate_range_end(mm, start_addr, end_addr);
 }
 
@@ -1376,19 +1369,21 @@ void unmap_vmas(struct mmu_gather *tlb,
  *
  * Caller must protect the VMA list
  */
-void zap_page_range(struct vm_area_struct *vma, unsigned long address,
+void zap_page_range(struct vm_area_struct *vma, unsigned long start,
 		unsigned long size, struct zap_details *details)
 {
 	struct mm_struct *mm = vma->vm_mm;
 	struct mmu_gather tlb;
-	unsigned long end = address + size;
-	unsigned long nr_accounted = 0;
+	unsigned long end = start + size;
 
 	lru_add_drain();
 	tlb_gather_mmu(&tlb, mm, 0);
 	update_hiwater_rss(mm);
-	unmap_vmas(&tlb, vma, address, end, &nr_accounted, details);
-	tlb_finish_mmu(&tlb, address, end);
+	mmu_notifier_invalidate_range_start(mm, start, end);
+	for ( ; vma && vma->vm_start < end; vma = vma->vm_next)
+		unmap_single_vma(&tlb, vma, start, end, details);
+	mmu_notifier_invalidate_range_end(mm, start, end);
+	tlb_finish_mmu(&tlb, start, end);
 }
 
 /**
@@ -1406,13 +1401,12 @@ static void zap_page_range_single(struct vm_area_struct *vma, unsigned long addr
 	struct mm_struct *mm = vma->vm_mm;
 	struct mmu_gather tlb;
 	unsigned long end = address + size;
-	unsigned long nr_accounted = 0;
 
 	lru_add_drain();
 	tlb_gather_mmu(&tlb, mm, 0);
 	update_hiwater_rss(mm);
 	mmu_notifier_invalidate_range_start(mm, address, end);
-	unmap_single_vma(&tlb, vma, address, end, &nr_accounted, details);
+	unmap_single_vma(&tlb, vma, address, end, details);
 	mmu_notifier_invalidate_range_end(mm, address, end);
 	tlb_finish_mmu(&tlb, address, end);
 }

mm/mmap.c

@@ -1889,15 +1889,20 @@ find_extend_vma(struct mm_struct * mm, unsigned long addr)
  */
 static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma)
 {
+	unsigned long nr_accounted = 0;
+
 	/* Update high watermark before we lower total_vm */
 	update_hiwater_vm(mm);
 	do {
 		long nrpages = vma_pages(vma);
 
+		if (vma->vm_flags & VM_ACCOUNT)
+			nr_accounted += nrpages;
 		mm->total_vm -= nrpages;
 		vm_stat_account(mm, vma->vm_flags, vma->vm_file, -nrpages);
 		vma = remove_vma(vma);
 	} while (vma);
+	vm_unacct_memory(nr_accounted);
 	validate_mm(mm);
 }
 
@@ -1912,13 +1917,11 @@ static void unmap_region(struct mm_struct *mm,
 {
 	struct vm_area_struct *next = prev? prev->vm_next: mm->mmap;
 	struct mmu_gather tlb;
-	unsigned long nr_accounted = 0;
 
 	lru_add_drain();
 	tlb_gather_mmu(&tlb, mm, 0);
 	update_hiwater_rss(mm);
-	unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL);
-	vm_unacct_memory(nr_accounted);
+	unmap_vmas(&tlb, vma, start, end);
 	free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,
 				 next ? next->vm_start : 0);
 	tlb_finish_mmu(&tlb, start, end);
@@ -2305,8 +2308,7 @@ void exit_mmap(struct mm_struct *mm)
 	tlb_gather_mmu(&tlb, mm, 1);
 	/* update_hiwater_rss(mm) here? but nobody should be looking */
 	/* Use -1 here to ensure all VMAs in the mm are unmapped */
-	unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
-	vm_unacct_memory(nr_accounted);
+	unmap_vmas(&tlb, vma, 0, -1);
 
 	free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0);
 	tlb_finish_mmu(&tlb, 0, -1);
@@ -2315,8 +2317,12 @@ void exit_mmap(struct mm_struct *mm)
 	 * Walk the list again, actually closing and freeing it,
 	 * with preemption enabled, without holding any MM locks.
 	 */
-	while (vma)
+	while (vma) {
+		if (vma->vm_flags & VM_ACCOUNT)
+			nr_accounted += vma_pages(vma);
 		vma = remove_vma(vma);
+	}
+	vm_unacct_memory(nr_accounted);
 
 	BUG_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT);
 }