]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
atomic: only take lock when the counter drops to zero on UP as well
authorJan Blunck <jblunck@suse.de>
Tue, 16 Jun 2009 22:33:33 +0000 (15:33 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 17 Jun 2009 02:47:47 +0000 (19:47 -0700)
commit417dcdf99ec9f8d8d6917189130bdc17cb67c678
tree4a97ab3ec286dda502ee7b3a16e0b6186cdc30d9
parenta7d932af06e8eee2163627d19898e18da5635449
atomic: only take lock when the counter drops to zero on UP as well

_atomic_dec_and_lock() should not unconditionally take the lock before
calling atomic_dec_and_test() in the UP case.  For consistency reasons it
should behave exactly like in the SMP case.

Besides that this works around the problem that with CONFIG_DEBUG_SPINLOCK
this spins in __spin_lock_debug() if the lock is already taken even if the
counter doesn't drop to 0.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: Valerie Aurora <vaurora@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib/dec_and_lock.c