Patch attempts to improve the performace of __arch_hweight functions by making them inline instead of current out of line implementation.
Testcase is to disable/enable SMT on a large (192 thread) POWER7 lpar. Program used for SMT disable/enable is "ppc64_cpu" with "--smt=[off/on]" option. Here are the perf output. In this case, __arch_hweight64 is called by __bitmap_weight. Without patch (ppc64_cpu --smt=off): 17.60% ppc64_cpu [kernel.kallsyms] [k] .deactivate_slab .... 4.85% ppc64_cpu [kernel.kallsyms] [k] .__bitmap_weight .... 1.36% ppc64_cpu [kernel.kallsyms] [k] .__disable_runtime 1.29% ppc64_cpu [kernel.kallsyms] [k] .__arch_hweight64 With patch (ppc64_cpu --smt=off): 17.29% ppc64_cpu [kernel.kallsyms] [k] .deactivate_slab .... 3.71% ppc64_cpu [kernel.kallsyms] [k] .__bitmap_weight 3.26% ppc64_cpu [kernel.kallsyms] [k] .build_overlap_sched_groups .... Without patch (ppc64_cpu --smt=on): 8.35% ppc64_cpu [kernel.kallsyms] [k] .strlen 7.00% ppc64_cpu [kernel.kallsyms] [k] .memset 6.78% ppc64_cpu [kernel.kallsyms] [k] .__bitmap_weight 4.23% ppc64_cpu [kernel.kallsyms] [k] .deactivate_slab .... 1.58% ppc64_cpu [kernel.kallsyms] [k] .refresh_zone_stat_thresholds 1.57% ppc64_cpu [kernel.kallsyms] [k] .__arch_hweight64 1.54% ppc64_cpu [kernel.kallsyms] [k] .__enable_runtime .... With patch (ppc64_cpu --smt=on): 9.44% ppc64_cpu [kernel.kallsyms] [k] .strlen 6.43% ppc64_cpu [kernel.kallsyms] [k] .memset 5.48% ppc64_cpu [kernel.kallsyms] [k] .__bitmap_weight 4.59% ppc64_cpu [kernel.kallsyms] [k] .insert_entry 4.29% ppc64_cpu [kernel.kallsyms] [k] .deactivate_slab .... Patch changes v2: 1. Removed the arch/powerpc/lib/hweight_64.S file. Signed-off-by: Madhavan Srinivasan <ma...@linux.vnet.ibm.com> --- arch/powerpc/include/asm/bitops.h | 130 ++++++++++++++++++++++++++++++++- arch/powerpc/include/asm/ppc-opcode.h | 6 ++ arch/powerpc/lib/Makefile | 2 +- arch/powerpc/lib/hweight_64.S | 110 ---------------------------- 4 files changed, 133 insertions(+), 115 deletions(-) delete mode 100644 arch/powerpc/lib/hweight_64.S diff --git a/arch/powerpc/include/asm/bitops.h b/arch/powerpc/include/asm/bitops.h index 910194e..136fe6a 100644 --- a/arch/powerpc/include/asm/bitops.h +++ b/arch/powerpc/include/asm/bitops.h @@ -43,8 +43,10 @@ #endif #include <linux/compiler.h> +#include <linux/types.h> #include <asm/asm-compat.h> #include <asm/synch.h> +#include <asm/cputable.h> /* * clear_bit doesn't imply a memory barrier @@ -263,10 +265,130 @@ static __inline__ int fls64(__u64 x) #endif /* __powerpc64__ */ #ifdef CONFIG_PPC64 -unsigned int __arch_hweight8(unsigned int w); -unsigned int __arch_hweight16(unsigned int w); -unsigned int __arch_hweight32(unsigned int w); -unsigned long __arch_hweight64(__u64 w); + +static inline unsigned int __arch_hweight8(unsigned int w) +{ + unsigned int register iop asm("r3") = w; + unsigned int register tmp asm("r4"); + __asm__ __volatile__ ( + stringify_in_c(BEGIN_FTR_SECTION) + "bl .__sw_hweight8;" + "nop;" + stringify_in_c(FTR_SECTION_ELSE) + PPC_POPCNTB_M(%1,%2) ";" + "clrldi %0,%1,64-8;" + stringify_in_c(ALT_FTR_SECTION_END_IFCLR((%3))) + : "=r" (iop), "=r" (tmp) + : "r" (iop), "i" (CPU_FTR_POPCNTB) + : "r0", "r1", "r5", "r6", "r7", "r8", "r9", + "r10", "r11", "r12", "r13", "r31", "lr", "cr0", "xer"); + + return iop; +} + +static inline unsigned int __arch_hweight16(unsigned int w) +{ + unsigned int register iop asm("r3") = w; + unsigned int register tmp asm("r4"); + __asm__ __volatile__ ( + stringify_in_c(BEGIN_FTR_SECTION) + "bl .__sw_hweight16;" + "nop;" + "nop;" + "nop;" + "nop;" + stringify_in_c(FTR_SECTION_ELSE) + stringify_in_c(BEGIN_FTR_SECTION_NESTED(50)) + PPC_POPCNTB_M(%0,%2) ";" + "srdi %1,%0,8;" + "add %0,%1,%0;" + "clrldi %0,%0,64-8;" + stringify_in_c(FTR_SECTION_ELSE_NESTED(50)) + "clrlwi %0,%2,16;" + PPC_POPCNTW_M(%1,%0) ";" + "clrldi %0,%1,64-8;" + stringify_in_c(ALT_FTR_SECTION_END_NESTED_IFCLR(%4,50)) + stringify_in_c(ALT_FTR_SECTION_END_IFCLR((%3))) + : "=r" (iop), "=r" (tmp) + : "r" (iop), "i" (CPU_FTR_POPCNTB), "i" (CPU_FTR_POPCNTD) + : "r0", "r1", "r5", "r6", "r7", "r8", "r9", + "r10", "r11", "r12", "r13", "r31", "lr", "cr0", "xer"); + + return iop; +} + +static inline unsigned int __arch_hweight32(unsigned int w) +{ + unsigned int register iop asm("r3") = w; + unsigned int register tmp asm("r4"); + __asm__ __volatile__ ( + stringify_in_c(BEGIN_FTR_SECTION) + "bl .__sw_hweight32;" + "nop;" + "nop;" + "nop;" + "nop;" + "nop;" + "nop;" + stringify_in_c(FTR_SECTION_ELSE) + stringify_in_c(BEGIN_FTR_SECTION_NESTED(51)) + PPC_POPCNTB_M(%0,%2) ";" + "srdi %1,%0,16;" + "add %0,%1,%0;" + "srdi %1,%0,8;" + "add %0,%1,%0;" + "clrldi %0,%0,64-8;" + stringify_in_c(FTR_SECTION_ELSE_NESTED(51)) + PPC_POPCNTW_M(%1,%2) ";" + "clrldi %0,%1,64-8;" + stringify_in_c(ALT_FTR_SECTION_END_NESTED_IFCLR(%4,51)) + stringify_in_c(ALT_FTR_SECTION_END_IFCLR((%3))) + : "=r" (iop), "=r" (tmp) + : "r" (iop), "i" (CPU_FTR_POPCNTB), "i" (CPU_FTR_POPCNTD) + : "r0", "r1", "r5", "r6", "r7", "r8", "r9", + "r10", "r11", "r12", "r13", "r31", "lr", "cr0", "xer"); + + return iop; +} + +static inline __u64 __arch_hweight64(__u64 w) +{ + __u64 register iop asm("r3") = w; + __u64 register tmp asm("r4"); + __asm__ __volatile__ ( + stringify_in_c(BEGIN_FTR_SECTION) + "bl .__sw_hweight64;" + "nop;" + "nop;" + "nop;" + "nop;" + "nop;" + "nop;" + "nop;" + "nop;" + stringify_in_c(FTR_SECTION_ELSE) + stringify_in_c(BEGIN_FTR_SECTION_NESTED(52)) + PPC_POPCNTB_M(%0,%2) ";" + "srdi %1,%0,32;" + "add %0,%1,%0;" + "srdi %1,%0,16;" + "add %0,%1,%0;" + "srdi %1,%0,8;" + "add %0,%1,%0;" + "clrldi %0,%0,64-8;" + stringify_in_c(FTR_SECTION_ELSE_NESTED(52)) + PPC_POPCNTD_M(%1,%2) ";" + "clrldi %0,%1,64-8;" + stringify_in_c(ALT_FTR_SECTION_END_NESTED_IFCLR(%4,52)) + stringify_in_c(ALT_FTR_SECTION_END_IFCLR((%3))) + : "=r" (iop), "=r" (tmp) + : "r" (iop), "i" (CPU_FTR_POPCNTB), "i" (CPU_FTR_POPCNTD) + : "r0", "r1", "r5", "r6", "r7", "r8", "r9", + "r10", "r11", "r12", "r13", "r31", "lr", "cr0", "xer"); + + return iop; +} + #include <asm-generic/bitops/const_hweight.h> #else #include <asm-generic/bitops/hweight.h> diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h index eccfc16..fc8767a 100644 --- a/arch/powerpc/include/asm/ppc-opcode.h +++ b/arch/powerpc/include/asm/ppc-opcode.h @@ -245,6 +245,12 @@ __PPC_RA(a) | __PPC_RS(s)) #define PPC_POPCNTW(a, s) stringify_in_c(.long PPC_INST_POPCNTW | \ __PPC_RA(a) | __PPC_RS(s)) +#define PPC_POPCNTB_M(a, s) stringify_in_c(.long PPC_INST_POPCNTB | \ + ___PPC_RA(a) | ___PPC_RS(s)) +#define PPC_POPCNTD_M(a, s) stringify_in_c(.long PPC_INST_POPCNTD | \ + ___PPC_RA(a) | ___PPC_RS(s)) +#define PPC_POPCNTW_M(a, s) stringify_in_c(.long PPC_INST_POPCNTW | \ + ___PPC_RA(a) | ___PPC_RS(s)) #define PPC_RFCI stringify_in_c(.long PPC_INST_RFCI) #define PPC_RFDI stringify_in_c(.long PPC_INST_RFDI) #define PPC_RFMCI stringify_in_c(.long PPC_INST_RFMCI) diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile index 4504332..66f553d 100644 --- a/arch/powerpc/lib/Makefile +++ b/arch/powerpc/lib/Makefile @@ -16,7 +16,7 @@ obj-$(CONFIG_HAS_IOMEM) += devres.o obj-$(CONFIG_PPC64) += copypage_64.o copyuser_64.o \ memcpy_64.o usercopy_64.o mem_64.o string.o \ - checksum_wrappers_64.o hweight_64.o \ + checksum_wrappers_64.o \ copyuser_power7.o string_64.o copypage_power7.o \ memcpy_power7.o obj-$(CONFIG_PPC_EMULATE_SSTEP) += sstep.o ldstfp.o diff --git a/arch/powerpc/lib/hweight_64.S b/arch/powerpc/lib/hweight_64.S deleted file mode 100644 index 9b96ff2..0000000 --- a/arch/powerpc/lib/hweight_64.S +++ /dev/null @@ -1,110 +0,0 @@ -/* - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - * - * Copyright (C) IBM Corporation, 2010 - * - * Author: Anton Blanchard <an...@au.ibm.com> - */ -#include <asm/processor.h> -#include <asm/ppc_asm.h> - -/* Note: This code relies on -mminimal-toc */ - -_GLOBAL(__arch_hweight8) -BEGIN_FTR_SECTION - b .__sw_hweight8 - nop - nop -FTR_SECTION_ELSE - PPC_POPCNTB(R3,R3) - clrldi r3,r3,64-8 - blr -ALT_FTR_SECTION_END_IFCLR(CPU_FTR_POPCNTB) - -_GLOBAL(__arch_hweight16) -BEGIN_FTR_SECTION - b .__sw_hweight16 - nop - nop - nop - nop -FTR_SECTION_ELSE - BEGIN_FTR_SECTION_NESTED(50) - PPC_POPCNTB(R3,R3) - srdi r4,r3,8 - add r3,r4,r3 - clrldi r3,r3,64-8 - blr - FTR_SECTION_ELSE_NESTED(50) - clrlwi r3,r3,16 - PPC_POPCNTW(R3,R3) - clrldi r3,r3,64-8 - blr - ALT_FTR_SECTION_END_NESTED_IFCLR(CPU_FTR_POPCNTD, 50) -ALT_FTR_SECTION_END_IFCLR(CPU_FTR_POPCNTB) - -_GLOBAL(__arch_hweight32) -BEGIN_FTR_SECTION - b .__sw_hweight32 - nop - nop - nop - nop - nop - nop -FTR_SECTION_ELSE - BEGIN_FTR_SECTION_NESTED(51) - PPC_POPCNTB(R3,R3) - srdi r4,r3,16 - add r3,r4,r3 - srdi r4,r3,8 - add r3,r4,r3 - clrldi r3,r3,64-8 - blr - FTR_SECTION_ELSE_NESTED(51) - PPC_POPCNTW(R3,R3) - clrldi r3,r3,64-8 - blr - ALT_FTR_SECTION_END_NESTED_IFCLR(CPU_FTR_POPCNTD, 51) -ALT_FTR_SECTION_END_IFCLR(CPU_FTR_POPCNTB) - -_GLOBAL(__arch_hweight64) -BEGIN_FTR_SECTION - b .__sw_hweight64 - nop - nop - nop - nop - nop - nop - nop - nop -FTR_SECTION_ELSE - BEGIN_FTR_SECTION_NESTED(52) - PPC_POPCNTB(R3,R3) - srdi r4,r3,32 - add r3,r4,r3 - srdi r4,r3,16 - add r3,r4,r3 - srdi r4,r3,8 - add r3,r4,r3 - clrldi r3,r3,64-8 - blr - FTR_SECTION_ELSE_NESTED(52) - PPC_POPCNTD(R3,R3) - clrldi r3,r3,64-8 - blr - ALT_FTR_SECTION_END_NESTED_IFCLR(CPU_FTR_POPCNTD, 52) -ALT_FTR_SECTION_END_IFCLR(CPU_FTR_POPCNTB) -- 1.7.10.4 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev