From: Arnd Bergmann Date: Sat, 18 Sep 2010 13:09:31 +0000 (+0200) Subject: fs/locks.c: prepare for BKL removal X-Git-Tag: v2.6.37-rc1~174^2~5 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b89f432133851a01c0d28822f11cbdcc15781a75;p=pandora-kernel.git fs/locks.c: prepare for BKL removal This prepares the removal of the big kernel lock from the file locking code. We still use the BKL as long as fs/lockd uses it and ceph might sleep, but we can flip the definition to a private spinlock as soon as that's done. All users outside of fs/lockd get converted to use lock_flocks() instead of lock_kernel() where appropriate. Based on an earlier patch to use a spinlock from Matthew Wilcox, who has attempted this a few times before, the earliest patch from over 10 years ago turned it into a semaphore, which ended up being slower than the BKL and was subsequently reverted. Someone should do some serious performance testing when this becomes a spinlock, since this has caused problems before. Using a spinlock should be at least as good as the BKL in theory, but who knows... Signed-off-by: Arnd Bergmann Acked-by: Matthew Wilcox Cc: Christoph Hellwig Cc: Trond Myklebust Cc: "J. Bruce Fields" Cc: Andrew Morton Cc: Miklos Szeredi Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: John Kacur Cc: Sage Weil Cc: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org --- Reading git-diff-tree failed