mm: gup: use get_user_pages_unlocked within get_user_pages_fast

This allows the get_user_pages_fast slow path to release the mmap_sem before blocking. Signed-off-by: Andrea Arcangeli <[email protected]> Reviewed-by: Kirill A. Shutemov <[email protected]> Cc: Andres Lagar-Cavilla <[email protected]> Cc: Peter Feiner <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
yoshikig · Feb 12, 2015 · a7b7807 · a7b7807
1 parent 0fd71a5
commit a7b7807
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Showing 7 changed files with 16 additions and 33 deletions.
diff --git a/arch/mips/mm/gup.c b/arch/mips/mm/gup.c
@@ -301,11 +301,9 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 	start += nr << PAGE_SHIFT;
 	pages += nr;
 
-	down_read(&mm->mmap_sem);
-	ret = get_user_pages(current, mm, start,
-				(end - start) >> PAGE_SHIFT,
-				write, 0, pages, NULL);
-	up_read(&mm->mmap_sem);
+	ret = get_user_pages_unlocked(current, mm, start,
+				      (end - start) >> PAGE_SHIFT,
+				      write, 0, pages);
 
 	/* Have to be a bit careful with return values */
 	if (nr > 0) {

diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c
@@ -235,10 +235,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 	/* Try to get the remaining pages with get_user_pages */
 	start += nr << PAGE_SHIFT;
 	pages += nr;
-	down_read(&mm->mmap_sem);
-	ret = get_user_pages(current, mm, start,
-			     nr_pages - nr, write, 0, pages, NULL);
-	up_read(&mm->mmap_sem);
+	ret = get_user_pages_unlocked(current, mm, start,
+			     nr_pages - nr, write, 0, pages);
 	/* Have to be a bit careful with return values */
 	if (nr > 0)
 		ret = (ret < 0) ? nr : ret + nr;

diff --git a/arch/sh/mm/gup.c b/arch/sh/mm/gup.c
@@ -257,10 +257,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 		start += nr << PAGE_SHIFT;
 		pages += nr;
 
-		down_read(&mm->mmap_sem);
-		ret = get_user_pages(current, mm, start,
-			(end - start) >> PAGE_SHIFT, write, 0, pages, NULL);
-		up_read(&mm->mmap_sem);
+		ret = get_user_pages_unlocked(current, mm, start,
+			(end - start) >> PAGE_SHIFT, write, 0, pages);
 
 		/* Have to be a bit careful with return values */
 		if (nr > 0) {

diff --git a/arch/sparc/mm/gup.c b/arch/sparc/mm/gup.c
@@ -249,10 +249,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 		start += nr << PAGE_SHIFT;
 		pages += nr;
 
-		down_read(&mm->mmap_sem);
-		ret = get_user_pages(current, mm, start,
-			(end - start) >> PAGE_SHIFT, write, 0, pages, NULL);
-		up_read(&mm->mmap_sem);
+		ret = get_user_pages_unlocked(current, mm, start,
+			(end - start) >> PAGE_SHIFT, write, 0, pages);
 
 		/* Have to be a bit careful with return values */
 		if (nr > 0) {

diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c
@@ -388,10 +388,9 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 		start += nr << PAGE_SHIFT;
 		pages += nr;
 
-		down_read(&mm->mmap_sem);
-		ret = get_user_pages(current, mm, start,
-			(end - start) >> PAGE_SHIFT, write, 0, pages, NULL);
-		up_read(&mm->mmap_sem);
+		ret = get_user_pages_unlocked(current, mm, start,
+					      (end - start) >> PAGE_SHIFT,
+					      write, 0, pages);
 
 		/* Have to be a bit careful with return values */
 		if (nr > 0) {

diff --git a/mm/gup.c b/mm/gup.c
@@ -1243,10 +1243,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 		start += nr << PAGE_SHIFT;
 		pages += nr;
 
-		down_read(&mm->mmap_sem);
-		ret = get_user_pages(current, mm, start,
-				     nr_pages - nr, write, 0, pages, NULL);
-		up_read(&mm->mmap_sem);
+		ret = get_user_pages_unlocked(current, mm, start,
+					      nr_pages - nr, write, 0, pages);
 
 		/* Have to be a bit careful with return values */
 		if (nr > 0) {

diff --git a/mm/util.c b/mm/util.c
@@ -240,14 +240,8 @@ int __weak get_user_pages_fast(unsigned long start,
 				int nr_pages, int write, struct page **pages)
 {
 	struct mm_struct *mm = current->mm;
-	int ret;
-
-	down_read(&mm->mmap_sem);
-	ret = get_user_pages(current, mm, start, nr_pages,
-					write, 0, pages, NULL);
-	up_read(&mm->mmap_sem);
-
-	return ret;
+	return get_user_pages_unlocked(current, mm, start, nr_pages,
+				       write, 0, pages);
 }
 EXPORT_SYMBOL_GPL(get_user_pages_fast);