On Fri, 2025-04-11 at 11:32 +0800, Shuai Xue wrote: > > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe. > > > > > > > > 在 2025/2/19 05:33, Ankur Arora 写道: > > > > Needed for cpuidle-haltpoll. > > > > > > > > Acked-by: Will Deacon <will@xxxxxxxxxx> > > > > Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx> > > > > --- > > > > arch/arm64/kernel/idle.c | 1 + > > > > 1 file changed, 1 insertion(+) > > > > > > > > diff --git a/arch/arm64/kernel/idle.c b/arch/arm64/kernel/idle.c > > > > index 05cfb347ec26..b85ba0df9b02 100644 > > > > --- a/arch/arm64/kernel/idle.c > > > > +++ b/arch/arm64/kernel/idle.c > > > > @@ -43,3 +43,4 @@ void __cpuidle arch_cpu_idle(void) > > > > */ > > > > cpu_do_idle(); > > > > Hi, Ankur, > > > > With haltpoll_driver registered, arch_cpu_idle() on x86 can select > > mwait_idle() in idle threads. > > > > It use MONITOR sets up an effective address range that is monitored > > for write-to-memory activities; MWAIT places the processor in > > an optimized state (this may vary between different implementations) > > until a write to the monitored address range occurs. > > > > Should arch_cpu_idle() on arm64 also use the LDXR/WFE > > to avoid wakeup IPI like x86 monitor/mwait? WFE will wake from the event stream, which can have short sub-ms periods on many systems. May be something to consider when WFET is more widely available. > > > > Thanks. > > Shuai > > > > Regards, Haris Okanovic AWS Graviton Software
