android_kernel_samsung_univ.../arch/parisc
John David Anglin 400db6fe74 parisc: Remove unnecessary barriers from spinlock.h
commit 3b885ac1dc35b87a39ee176a6c7e2af9c789d8b8 upstream.

Now that mb() is an instruction barrier, it will slow performance if we issue
unnecessary barriers.

The spinlock defines have a number of unnecessary barriers.  The __ldcw()
define is both a hardware and compiler barrier.  The mb() barriers in the
routines using __ldcw() serve no purpose.

The only barrier needed is the one in arch_spin_unlock().  We need to ensure
all accesses are complete prior to releasing the lock.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-24 13:27:01 +02:00
..
configs rtmutex: Delete scriptable tester 2015-07-20 11:45:45 +02:00
include parisc: Remove unnecessary barriers from spinlock.h 2018-08-24 13:27:01 +02:00
kernel parisc: Remove ordered stores from syscall.S 2018-08-24 13:27:00 +02:00
lib parisc: Unbreak handling exceptions from kernel modules 2016-04-20 15:41:52 +09:00
math-emu
mm parisc: Report SIGSEGV instead of SIGBUS when running out of stack 2017-07-21 07:44:56 +02:00
oprofile
defpalo.conf
install.sh
Kconfig parisc: Enable CONFIG_MLONGCALLS by default 2018-08-15 17:42:05 +02:00
Kconfig.debug
Makefile Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2015-02-19 10:07:08 -08:00
nm