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[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>
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parent
0d9a490abe
commit
39005d022a
1 changed files with 10 additions and 3 deletions
13
fs/locks.c
13
fs/locks.c
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@ -794,7 +794,8 @@ out:
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static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request, struct file_lock *conflock)
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{
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struct file_lock *fl;
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struct file_lock *new_fl, *new_fl2;
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struct file_lock *new_fl = NULL;
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struct file_lock *new_fl2 = NULL;
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struct file_lock *left = NULL;
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struct file_lock *right = NULL;
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struct file_lock **before;
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@ -803,9 +804,15 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
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/*
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* We may need two file_lock structures for this operation,
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* so we get them in advance to avoid races.
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*
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* In some cases we can be sure, that no new locks will be needed
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*/
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new_fl = locks_alloc_lock();
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new_fl2 = locks_alloc_lock();
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if (!(request->fl_flags & FL_ACCESS) &&
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(request->fl_type != F_UNLCK ||
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request->fl_start != 0 || request->fl_end != OFFSET_MAX)) {
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new_fl = locks_alloc_lock();
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new_fl2 = locks_alloc_lock();
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}
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lock_kernel();
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if (request->fl_type != F_UNLCK) {
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