Re: [Qemu-devel] [PATCH kvm-unit-tests v8 03/10] arm/arm64: add some delay routines

[Andrew Jones]

On Tue, Dec 27, 2016 at 10:27:25AM -0500, Christopher Covington wrote:
> On 12/09/2016 07:15 AM, Andrew Jones wrote:
> > On Fri, Dec 09, 2016 at 11:41:06AM +0000, Andre Przywara wrote:
> >> Hi,
> >>
> >> On 08/12/16 17:50, Andrew Jones wrote:
> >>> Allow a thread to wait some specified amount of time. Can
> >>> specify in cycles, usecs, and msecs.
> 
> >>> +++ b/lib/arm/asm/delay.h
> >>> @@ -0,0 +1,14 @@
> >>> +#ifndef _ASMARM_DELAY_H_
> >>> +#define _ASMARM_DELAY_H_
> >>> +/*
> >>> + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <address@hidden>
> >>> + *
> >>> + * This work is licensed under the terms of the GNU LGPL, version 2.
> >>> + */
> >>> +#include <libcflat.h>
> >>> +
> >>> +extern void delay(u64 cycles);
> >>
> >> Nit: Shouldn't this parameter be called "ticks"? Cycles might be a bit
> >> misleading, especially since this prototype is the only documentation on
> >> this. You might just want to fix this when applying the patches.
> > 
> > Right or wrong the kernel uses 'cycles' for this function, named
> > __timer_delay for arm and __delay for arm64. I guess I prefer
> > consistency here.
> 
> I too expect timers to tick and CPUs to cycle. The benefit of
> parameter-name-precise consistency with the Linux source is not
> obvious to me.
>

I just didn't have a strong enough opinion on it to change it. It appears
I'm in a minority though. As this is in master already, patches welcome :)

Thanks,
drew