From 7012b02a2b2c42bb1e1d95040a6e3bb59c7284f7 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 21 Jun 2013 08:58:22 -0400 Subject: locks: move file_lock_list to a set of percpu hlist_heads and convert file_lock_lock to an lglock The file_lock_list is only used for /proc/locks. The vastly common case is for locks to be put onto the list and come off again, without ever being traversed. Help optimize for this use-case by moving to percpu hlist_head-s. At the same time, we can make the locking less contentious by moving to an lglock. When iterating over the lists for /proc/locks, we must take the global lock and then iterate over each CPU's list in turn. This change necessitates a new fl_link_cpu field to keep track of which CPU the entry is on. On x86_64 at least, this field is placed within an existing hole in the struct to avoid growing the size. Signed-off-by: Jeff Layton Acked-by: J. Bruce Fields Signed-off-by: Al Viro --- include/linux/fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/fs.h') diff --git a/include/linux/fs.h b/include/linux/fs.h index 99be011e00de..834c9e5113d9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -954,6 +954,7 @@ struct file_lock { unsigned int fl_flags; unsigned char fl_type; unsigned int fl_pid; + int fl_link_cpu; /* what cpu's list is this on? */ struct pid *fl_nspid; wait_queue_head_t fl_wait; struct file *fl_file; -- cgit v1.2.3