linux/arch/ia64
Peter Zijlstra 6428671bae locking/mutex: Optimize mutex_trylock() fast-path
A while back Viro posted a number of 'interesting' mutex_is_locked()
users on IRC, one of those was RCU.

RCU seems to use mutex_is_locked() to avoid doing mutex_trylock(), the
regular load before modify pattern.

While the use isn't wrong per se, its curious in that its needed at all,
mutex_trylock() should be good enough on its own to avoid the pointless
cacheline bounces.

So fix those and remove the mutex_is_locked() (ab)use from RCU.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hpe.com>
Link: http://lkml.kernel.org/r/20160601185815.GW3190@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 15:17:01 +02:00
..
configs [IA64] refresh arch/ia64/configs/* using "make savedefconfig" 2014-09-23 11:09:29 -07:00
dig Disintegrate asm/system.h for IA64 2012-03-28 18:30:02 +01:00
hp tty: Replace TTY_IO_ERROR bit tests with tty_io_error() 2016-04-30 09:26:55 -07:00
include locking/mutex: Optimize mutex_trylock() fast-path 2016-06-08 15:17:01 +02:00
kernel exit_thread: accept a task parameter to be exited 2016-05-20 17:58:30 -07:00
lib Merge branch 'master' into for-next 2016-04-18 11:18:55 +02:00
mm ia64/extable: use generic search and sort routines 2016-03-22 15:36:02 -07:00
oprofile Disintegrate asm/system.h for IA64 2012-03-28 18:30:02 +01:00
pci PCI: Set ROM shadow location in arch code, not in PCI core 2016-03-08 12:14:31 -06:00
scripts ia64: remove paravirt code 2015-06-10 14:26:32 -07:00
sn ia64: Reduce stack usage by iterating over nodemask 2016-05-05 10:29:14 -07:00
uv
install.sh
Kconfig exit_thread: remove empty bodies 2016-05-20 17:58:30 -07:00
Kconfig.debug
Makefile kbuild: drop redundant "PHONY += FORCE" 2016-04-20 10:38:40 +02:00
module.lds