powerpc/mm: Add a parameter to disable 1TB segs

[oliver]

On Tue, Jul 5, 2016 at 10:24 AM, Michael Neuling <mikey at neuling.org> wrote:
> On Mon, 2016-07-04 at 16:09 +1000, Michael Ellerman wrote:
>> On Mon, 2016-04-07 at 00:44:04 UTC, Oliver O'Halloran wrote:
>> >
>> > This patch adds the kernel command line parameter "no_tb_segs" which
>> > forces the kernel to use 256MB rather than 1TB segments. Forcing the
>> > use
>> > of 256MB segments makes it considerably easier to test code that
>> > depends
>> > on an SLB miss occurring.
>> That's a fairly awful name :)
>>
>> Can you call it "disable_1T_segments" ?
>>
>>
>> It should also be mentioned in Documentation/kernel-parameters.txt, with
>> emphasis that it's a debug option and powerpc only.
>
> To that end, should we add "powerpc_" at the start of the option?

I don't think it's necessary. There are annotations in
kernel-parameters.txt that indicate what options are arch specific and
it looks like none of the existing architecture specific options are
prefixed.

>
> Mikey