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Borislav Petkov f21262b8e0 x86/alternatives: Switch AMD F15h and later to the P6 NOPs 
Software optimization guides for both F15h and F16h cite those
NOPs as the optimal ones. A microbenchmark confirms that
actually even older families are better with the single-insn
NOPs so switch to them for the alternatives.

Cycles count below includes the loop overhead of the measurement
but that overhead is the same with all runs.

	F10h, revE:
	-----------
	Running NOP tests, 1000 NOPs x 1000000 repetitions

	K8:
			      90     288.212282 cycles
			   66 90     288.220840 cycles
			66 66 90     288.219447 cycles
		     66 66 66 90     288.223204 cycles
		  66 66 90 66 90     571.393424 cycles
	       66 66 90 66 66 90     571.374919 cycles
	    66 66 66 90 66 66 90     572.249281 cycles
	 66 66 66 90 66 66 66 90     571.388651 cycles

	P6:
			      90     288.214193 cycles
			   66 90     288.225550 cycles
			0f 1f 00     288.224441 cycles
		     0f 1f 40 00     288.225030 cycles
		  0f 1f 44 00 00     288.233558 cycles
	       66 0f 1f 44 00 00     324.792342 cycles
	    0f 1f 80 00 00 00 00     325.657462 cycles
	 0f 1f 84 00 00 00 00 00     430.246643 cycles

	F14h:
	----
	Running NOP tests, 1000 NOPs x 1000000 repetitions

	K8:
			      90     510.404890 cycles
			   66 90     510.432117 cycles
			66 66 90     510.561858 cycles
		     66 66 66 90     510.541865 cycles
		  66 66 90 66 90    1014.192782 cycles
	       66 66 90 66 66 90    1014.226546 cycles
	    66 66 66 90 66 66 90    1014.334299 cycles
	 66 66 66 90 66 66 66 90    1014.381205 cycles

	P6:
			      90     510.436710 cycles
			   66 90     510.448229 cycles
			0f 1f 00     510.545100 cycles
		     0f 1f 40 00     510.502792 cycles
		  0f 1f 44 00 00     510.589517 cycles
	       66 0f 1f 44 00 00     510.611462 cycles
	    0f 1f 80 00 00 00 00     511.166794 cycles
	 0f 1f 84 00 00 00 00 00     511.651641 cycles

	F15h:
	-----
	Running NOP tests, 1000 NOPs x 1000000 repetitions

	K8:
			      90     243.128396 cycles
			   66 90     243.129883 cycles
			66 66 90     243.131631 cycles
		     66 66 66 90     242.499324 cycles
		  66 66 90 66 90     481.829083 cycles
	       66 66 90 66 66 90     481.884413 cycles
	    66 66 66 90 66 66 90     481.851446 cycles
	 66 66 66 90 66 66 66 90     481.409220 cycles

	P6:
			      90     243.127026 cycles
			   66 90     243.130711 cycles
			0f 1f 00     243.122747 cycles
		     0f 1f 40 00     242.497617 cycles
		  0f 1f 44 00 00     245.354461 cycles
	       66 0f 1f 44 00 00     361.930417 cycles
	    0f 1f 80 00 00 00 00     362.844944 cycles
	 0f 1f 84 00 00 00 00 00     480.514948 cycles

	F16h:
	-----
	Running NOP tests, 1000 NOPs x 1000000 repetitions

	K8:
			      90     507.793298 cycles
			   66 90     507.789636 cycles
			66 66 90     507.826490 cycles
		     66 66 66 90     507.859075 cycles
		  66 66 90 66 90    1008.663129 cycles
	       66 66 90 66 66 90    1008.696259 cycles
	    66 66 66 90 66 66 90    1008.692517 cycles
	 66 66 66 90 66 66 66 90    1008.755399 cycles

	P6:
			      90     507.795232 cycles
			   66 90     507.794761 cycles
			0f 1f 00     507.834901 cycles
		     0f 1f 40 00     507.822629 cycles
		  0f 1f 44 00 00     507.838493 cycles
	       66 0f 1f 44 00 00     507.908597 cycles
	    0f 1f 80 00 00 00 00     507.946417 cycles
	 0f 1f 84 00 00 00 00 00     507.954960 cycles

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431332153-18566-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11 10:26:05 +02:00
..
alpha alpha: forward declare struct pt_regs in processor.h 2015-04-17 09:03:53 -04:00
arc ARC changes for 4.1-rc1: 2015-04-24 07:55:54 -07:00
arm xen: Add __GFP_DMA flag when xen_swiotlb_init gets free pages on ARM 2015-05-06 15:02:58 +01:00
arm64 arm64: perf: Fix the pmu node name in warning message 2015-04-30 12:11:30 +01:00
avr32 Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2015-04-15 13:53:55 -07:00
blackfin blackfin updates for Linux 4.1 2015-04-24 07:58:07 -07:00
c6x C6X Fixes for v4.1 2015-04-16 18:48:55 -04:00
cris CRIS changes for 4.1 2015-04-26 13:31:05 -07:00
frv Devicetree updates for 4.1: 2015-04-24 08:46:18 -07:00
hexagon Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2015-04-15 13:53:55 -07:00
ia64 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
m32r Char/Misc driver patches for 4.1-rc1 2015-04-21 09:42:58 -07:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2015-04-20 10:12:29 -07:00
metag Metag architecture changes for v4.1 2015-04-24 07:56:50 -07:00
microblaze microblaze: use asm-generic for seccomp.h 2015-04-17 09:04:10 -04:00
mips TTY/Serial patches for 4.1-rc1 2015-04-21 09:33:10 -07:00
mn10300 Devicetree updates for 4.1: 2015-04-24 08:46:18 -07:00
nios2 nios2 update for v4.1-rc1 2015-04-24 07:59:07 -07:00
openrisc Merge branch 'akpm' (patches from Andrew) 2015-04-15 16:39:15 -07:00
parisc parisc: Replace PT_NLEVELS with CONFIG_PGTABLE_LEVELS 2015-04-21 22:04:03 +02:00
powerpc powerpc/powernv: Restore non-volatile CRs after nap 2015-05-01 16:55:11 +10:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2015-04-28 09:58:46 -07:00
score arch: Remove exec_domain from remaining archs 2015-04-12 21:03:30 +02:00
sh Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-04-24 09:49:37 -07:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2015-04-21 23:21:34 -07:00
tile tile: properly use node_isset() on a nodemask_t 2015-04-28 10:36:45 -04:00
um Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2015-04-15 13:53:55 -07:00
unicore32 Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2015-04-15 13:53:55 -07:00
x86 x86/alternatives: Switch AMD F15h and later to the P6 NOPs 2015-05-11 10:26:05 +02:00
xtensa Xtensa changes and fixes for 4.1 2015-04-17 15:32:30 -04:00
.gitignore
Kconfig powerpc updates for 4.1 2015-04-16 13:53:32 -05:00