diff options
| author | Masao Uebayashi <uebayasi@cvs.openbsd.org> | 2014-07-11 10:53:08 +0000 |
|---|---|---|
| committer | Masao Uebayashi <uebayasi@cvs.openbsd.org> | 2014-07-11 10:53:08 +0000 |
| commit | 123f4b6634c6f64980c8a879dc8140fcc706d6d2 (patch) | |
| tree | 8f16526685cec43a88ad22499b7316fe46507593 /sys/arch/arm/include | |
| parent | 7153f32429c8f459cac9dbed87a626718d2b84b9 (diff) | |
CPU_BUSY_CYCLE(): A new MI statement for busy loop power reduction
The new CPU_BUSY_CYCLE() may be put in a busy loop body so that CPU can reduce
power consumption, as Linux's cpu_relax() and FreeBSD's cpu_spinwait(). To
start minimally, use PAUSE on i386/amd64 and empty on others. The name is
chosen following the existing cpu_idle_*() functions. Naming and API may be
polished later.
OK kettenis@
Diffstat (limited to 'sys/arch/arm/include')
| -rw-r--r-- | sys/arch/arm/include/cpu.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sys/arch/arm/include/cpu.h b/sys/arch/arm/include/cpu.h index a75285cd8fc..f00363cac0c 100644 --- a/sys/arch/arm/include/cpu.h +++ b/sys/arch/arm/include/cpu.h @@ -1,4 +1,4 @@ -/* $OpenBSD: cpu.h,v 1.38 2013/09/12 11:43:51 patrick Exp $ */ +/* $OpenBSD: cpu.h,v 1.39 2014/07/11 10:53:07 uebayasi Exp $ */ /* $NetBSD: cpu.h,v 1.34 2003/06/23 11:01:08 martin Exp $ */ /* @@ -234,6 +234,8 @@ extern struct cpu_info *cpu_info[MAXCPUS]; void cpu_boot_secondary_processors(void); #endif /* !MULTIPROCESSOR */ +#define CPU_BUSY_CYCLE() do {} while (0) + #define curpcb curcpu()->ci_curpcb /* |