[PATCH 1/4] powerpc/tm: Add commandline option to disable hardware transactional memory

[Michael Ellerman]

Breno Leitao <leitao at debian.org> writes:
> On Sat, Oct 21, 2017 at 11:58:47AM +1100, Michael Neuling wrote:
>> On Fri, 2017-10-20 at 09:45 -0200, Breno Leitao wrote:
>> > On Thu, Oct 12, 2017 at 09:17:16PM +1100, Michael Ellerman wrote:
>> > > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
>> > > index f83056297441..d9bd6555f980 100644
>> > > --- a/arch/powerpc/kernel/prom.c
>> > > +++ b/arch/powerpc/kernel/prom.c
>> > > @@ -658,6 +658,35 @@ static void __init early_reserve_mem(void)
>> > >  #endif
>> > >  }
>> > >  
>> > > +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
>> > > +static bool tm_disabled __initdata;
>> > 
>> > I think the name 'tm_disabled' might cause more confusion on the TM
>> > code. Mainly because we already have tm_enable() and tm_enabled()
>> > functions which are related to the MSR register and TM bit, and, with
>> > your new variable, tm_enabled() and tm_disabled are not going to be
>> > exclusionary. Neither tm_enable() with be able to toggle the tm_disabled
>> > value.

I've merged it with that name, but I'm happy to take an incremental
patch to give it a better name.

>> Got a proposal for better names?
>
> That is the hardest part, but I thought about something as:
>
>  * tm_disabled_on_boot

Maybe.

>  * tm_off

Nah.

>  * tm_explicit_disabled

Maybe.

>  * tm_feature_disabled

No that's not quite accurate.

>  * tm_enablement_disabled

I refuse to use "enablement" ;)

> I think these names, although a bit longer, might avoid the confusion
> with tm_enable/tm_enabled nomenclature.

tm_cmdline_disabled would be OK. Or tm_force_disable, or ...

cheers