Inspired by Benjamin Herrenschmidt, this patch series try to reduce the
cpu/mmu feature checking overhead by using jump label. The following is
the difference of the run path of cpu_has_feature between before and after
applying these patches:
before after
addis r10,r2,1 b xxx
addi r9,r10,-2280 b xxx (This will also be omitted if the
ld r9,0(r9) feature is not set)
ld r9,16(r9)
rldicl. r8,r9,55,63
beq c000000000037c94
This patch series passed the build test for almost all the defconfig of ppc.
There does have some broken for some configs. But they are not related to this
change. This also passed allyesconfig for x86. Boot test on p2020rdb and
p5020ds boards.
Kevin Hao (5):
jump_label: factor out the base part of jump_label.h to a separate
file
jump_label: also include linux/atomic.h when jump label is enabled
powerpc: move the cpu_has_feature to a separate file
powerpc: use the jump label for cpu_has_feature
powerpc: use jump label for mmu_has_feature
arch/powerpc/include/asm/cacheflush.h | 1 +
arch/powerpc/include/asm/cpufeatures.h | 42 ++++++++++
arch/powerpc/include/asm/cputable.h | 8 --
arch/powerpc/include/asm/cputime.h | 1 +
arch/powerpc/include/asm/dbell.h | 1 +
arch/powerpc/include/asm/dcr-native.h | 1 +
arch/powerpc/include/asm/mman.h | 1 +
arch/powerpc/include/asm/mmu.h | 19 +++++
arch/powerpc/include/asm/time.h | 1 +
arch/powerpc/kernel/align.c | 1 +
arch/powerpc/kernel/cputable.c | 43 ++++++++++
arch/powerpc/kernel/irq.c | 1 +
arch/powerpc/kernel/process.c | 1 +
arch/powerpc/kernel/setup-common.c | 1 +
arch/powerpc/kernel/setup_32.c | 1 +
arch/powerpc/kernel/smp.c | 1 +
arch/powerpc/oprofile/op_model_rs64.c | 1 +
arch/powerpc/platforms/cell/pervasive.c | 1 +
arch/powerpc/xmon/ppc-dis.c | 1 +
include/linux/jump_label.h | 132 +----------------------------
include/linux/jump_label_base.h | 142 ++++++++++++++++++++++++++++++++
21 files changed, 263 insertions(+), 138 deletions(-)
create mode 100644 arch/powerpc/include/asm/cpufeatures.h
create mode 100644 include/linux/jump_label_base.h
--
1.8.3.1
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