6dbde35308
It is an optimization and a cleanup, and adds the following new generic percpu methods: percpu_read() percpu_write() percpu_add() percpu_sub() percpu_and() percpu_or() percpu_xor() and implements support for them on x86. (other architectures will fall back to a default implementation) The advantage is that for example to read a local percpu variable, instead of this sequence: return __get_cpu_var(var); ffffffff8102ca2b: 48 8b 14 fd 80 09 74 mov -0x7e8bf680(,%rdi,8),%rdx ffffffff8102ca32: 81 ffffffff8102ca33: 48 c7 c0 d8 59 00 00 mov $0x59d8,%rax ffffffff8102ca3a: 48 8b 04 10 mov (%rax,%rdx,1),%rax We can get a single instruction by using the optimized variants: return percpu_read(var); ffffffff8102ca3f: 65 48 8b 05 91 8f fd mov %gs:0x7efd8f91(%rip),%rax I also cleaned up the x86-specific APIs and made the x86 code use these new generic percpu primitives. tj: * fixed generic percpu_sub() definition as Roel Kluin pointed out * added percpu_and() for completeness's sake * made generic percpu ops atomic against preemption Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Tejun Heo <tj@kernel.org> |
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.. | ||
bitops | ||
4level-fixup.h | ||
atomic.h | ||
audit_change_attr.h | ||
audit_dir_write.h | ||
audit_read.h | ||
audit_signal.h | ||
audit_write.h | ||
bitops.h | ||
bug.h | ||
cmpxchg-local.h | ||
cmpxchg.h | ||
cputime.h | ||
device.h | ||
div64.h | ||
dma-coherent.h | ||
dma-mapping-broken.h | ||
dma-mapping.h | ||
emergency-restart.h | ||
errno-base.h | ||
errno.h | ||
fcntl.h | ||
futex.h | ||
gpio.h | ||
ide_iops.h | ||
int-l64.h | ||
int-ll64.h | ||
ioctl.h | ||
iomap.h | ||
irq_regs.h | ||
Kbuild | ||
Kbuild.asm | ||
kdebug.h | ||
libata-portmap.h | ||
local.h | ||
memory_model.h | ||
mm_hooks.h | ||
mman.h | ||
mutex-dec.h | ||
mutex-null.h | ||
mutex-xchg.h | ||
page.h | ||
pci-dma-compat.h | ||
pci.h | ||
percpu.h | ||
pgtable-nopmd.h | ||
pgtable-nopud.h | ||
pgtable.h | ||
poll.h | ||
resource.h | ||
rtc.h | ||
sections.h | ||
siginfo.h | ||
signal.h | ||
statfs.h | ||
syscall.h | ||
termios.h | ||
tlb.h | ||
topology.h | ||
uaccess.h | ||
vmlinux.lds.h | ||
xor.h |