The patch titled
locks: don't do unnecessary allocations
has been removed from the -mm tree. Its filename is
locks-dont-do-unnecessary-allocations.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: locks: don't do unnecessary allocations
From: Miklos Szeredi <miklos@xxxxxxxxxx>
posix_lock_file() always allocates new locks in advance, even if it's easy to
determine that no allocations will be needed.
Optimize these cases:
- FL_ACCESS flag is set
- Unlocking the whole range
Signed-off-by: Miklos Szeredi <miklos@xxxxxxxxxx>
Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/locks.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff -puN fs/locks.c~locks-dont-do-unnecessary-allocations fs/locks.c
--- a/fs/locks.c~locks-dont-do-unnecessary-allocations
+++ a/fs/locks.c
@@ -794,7 +794,8 @@ out:
static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request, struct file_lock *conflock)
{
struct file_lock *fl;
- struct file_lock *new_fl, *new_fl2;
+ struct file_lock *new_fl = NULL;
+ struct file_lock *new_fl2 = NULL;
struct file_lock *left = NULL;
struct file_lock *right = NULL;
struct file_lock **before;
@@ -803,9 +804,15 @@ static int __posix_lock_file_conf(struct
/*
* We may need two file_lock structures for this operation,
* so we get them in advance to avoid races.
+ *
+ * In some cases we can be sure, that no new locks will be needed
*/
- new_fl = locks_alloc_lock();
- new_fl2 = locks_alloc_lock();
+ if (!(request->fl_flags & FL_ACCESS) &&
+ (request->fl_type != F_UNLCK ||
+ request->fl_start != 0 || request->fl_end != OFFSET_MAX)) {
+ new_fl = locks_alloc_lock();
+ new_fl2 = locks_alloc_lock();
+ }
lock_kernel();
if (request->fl_type != F_UNLCK) {
_
Patches currently in -mm which might be from miklos@xxxxxxxxxx are
origin.patch
fuse-use-misc_major.patch
fuse-no-backgrounding-on-interrupt.patch
fuse-add-control-filesystem.patch
fuse-add-control-filesystem-get_sb_single-fix.patch
fuse-add-control-filesystem-printk-fix.patch
fuse-add-posix-file-locking-support.patch
fuse-ensure-flush-reaches-userspace.patch
fuse-rename-the-interrupted-flag.patch
fuse-add-request-interruption.patch
-
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