linux-brain/arch/parisc
John David Anglin eba0611e98 parisc: Remove unnecessary barriers from spinlock.h
commit 3b885ac1dc 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 13:12:41 +02:00
..
configs mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 2016-08-30 10:10:21 -07:00
include parisc: Remove unnecessary barriers from spinlock.h 2018-08-24 13:12:41 +02:00
kernel parisc: Remove ordered stores from syscall.S 2018-08-24 13:12:41 +02:00
lib parisc: fix bugs in pa_memcpy 2017-04-21 09:31:20 +02:00
math-emu parisc: Fix typo in fpudispatch.c 2016-05-22 22:29:07 +02:00
mm parisc: Report SIGSEGV instead of SIGBUS when running out of stack 2017-07-21 07:42:20 +02:00
oprofile oprofile: more whitespace fixes 2008-10-15 20:55:51 +02:00
Kconfig parisc: Enable CONFIG_MLONGCALLS by default 2018-08-15 18:14:41 +02:00
Kconfig.debug parisc: Fix ftrace function tracer 2016-04-14 17:47:19 +02:00
Makefile parisc: Fix ftrace function tracer 2016-04-14 17:47:19 +02:00
defpalo.conf parisc: switch to gzip-compressed vmlinuz kernel 2013-07-09 22:09:20 +02:00
install.sh parisc: make "make install" not depend on vmlinux 2013-11-07 22:28:06 +01:00
nm Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00