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| author | Miklos Szeredi <miklos@szeredi.hu> | 2006-06-23 02:05:10 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-23 07:43:02 -0700 |
| commit | 39005d022ad221b76dc2de0ac62ef475a796433b (patch) | |
| tree | e0a36fec7076d48764f0588b9ce09ce8e9f067ff /fs | |
| parent | 0d9a490abe1f69fda220f7866f6f23af41daa128 (diff) | |
| download | linux-3.10-39005d022ad221b76dc2de0ac62ef475a796433b.tar.gz linux-3.10-39005d022ad221b76dc2de0ac62ef475a796433b.tar.bz2 linux-3.10-39005d022ad221b76dc2de0ac62ef475a796433b.zip | |
[PATCH] locks: don't do unnecessary allocations
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@szeredi.hu>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/locks.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/locks.c b/fs/locks.c index c5ac6b40e76..2344f241c68 100644 --- a/fs/locks.c +++ b/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 inode *inode, struct file_lock *request /* * 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) { |