Re: [PATCH 3/5] MIPS: Set page size to 16KB for malta SMP defconfigs

[Markos Chandras <Markos.Chandras@imgtec.com>]

On 02/21/2014 05:38 PM, Ralf Baechle wrote:
> On Thu, Feb 20, 2014 at 02:00:26PM +0000, Markos Chandras wrote:
>
>> From: Paul Burton <paul.burton@imgtec.com>
>>
>> For Malta defconfigs which may run on an SMP configuration without
>> hardware cache anti-aliasing, a 16KB page size is a safer default.
>> Most notably at the moment it will avoid cache aliasing issues for
>> multicore proAptiv systems.
>
> You're aware that this may cause binary compatibility issues with old
> userland?  So far the defaults were chosen to maximise compatibility
> over performance.
>
>    Ralf
>
Hi Ralf,

Are you referring to programs hard coding the page size to 4k instead of 
using the getpagesize()? Well yes this could be a problem. But is that a 
real problem? We are changing the default value so whoever has such an 
old userland can easily switch to the 4k page size. It may also be a 
good opportunity to expose such application and get the fixed properly 
:) But if that's not acceptable, we can drop the patch. Paul what do you 
think?

-- 
markos