linux_dsm_epyc7002/arch/x86
Arjan van de Ven 79e1dd05d1 x86: Provide an alternative() based cmpxchg64()
cmpxchg64() today generates, to quote Linus, "barf bag" code.

cmpxchg64() is about to get used in the scheduler to fix a bug there,
but it's a prerequisite that cmpxchg64() first be made non-sucking.

This patch turns cmpxchg64() into an efficient implementation that
uses the alternative() mechanism to just use the raw instruction on
all modern systems.

Note: the fallback is NOT smp safe, just like the current fallback
is not SMP safe. (Interested parties with i486 based SMP systems
are welcome to submit fix patches for that.)

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
[ fixed asm constraint bug ]
Fixed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090930170754.0886ff2e@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-30 22:55:59 +02:00
..
boot Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
configs tracing: Rename FTRACE_SYSCALLS for tracepoints 2009-08-26 00:17:35 +02:00
crypto Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-14 07:57:32 -07:00
ia32 perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
include/asm x86: Provide an alternative() based cmpxchg64() 2009-09-30 22:55:59 +02:00
kernel x86: Provide an alternative() based cmpxchg64() 2009-09-30 22:55:59 +02:00
kvm Merge branch 'kvm-updates/2.6.32' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2009-09-14 17:43:43 -07:00
lguest lguest: move panic notifier registration to its expected place. 2009-09-23 22:26:44 +09:30
lib x86: Provide an alternative() based cmpxchg64() 2009-09-30 22:55:59 +02:00
math-emu Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2 2009-03-27 17:28:43 +01:00
mm Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
oprofile perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
pci const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
power x86: Remove final bits of CONFIG_X86_OLD_MCE 2009-09-18 08:31:23 +02:00
vdso kbuild: rename ld-option to cc-ldoption 2009-09-20 12:27:42 +02:00
video
xen Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
Kbuild x86: standardize Kbuild rules 2009-04-16 18:09:02 +02:00
Kconfig x86: Fix hwpoison code related build failure on 32-bit NUMAQ 2009-09-27 09:55:11 +02:00
Kconfig.cpu x86: add specific support for Intel Atom architecture 2009-08-23 11:20:02 +02:00
Kconfig.debug kmemcheck: make kconfig accessible for other architectures 2009-06-15 15:49:17 +02:00
Makefile kbuild: use INSTALLKERNEL to select customized installkernel script 2009-09-20 12:18:14 +02:00
Makefile_32.cpu x86: add specific support for Intel Atom architecture 2009-08-23 11:20:02 +02:00