From: Markos Chandras <Markos.Chandras@imgtec.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: <linux-mips@linux-mips.org>, Paul Burton <paul.burton@imgtec.com>
Subject: Re: [PATCH 3/5] MIPS: Set page size to 16KB for malta SMP defconfigs
Date: Mon, 3 Mar 2014 14:06:18 +0000 [thread overview]
Message-ID: <53148C5A.7020101@imgtec.com> (raw)
In-Reply-To: <20140221173829.GI19285@linux-mips.org>
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
WARNING: multiple messages have this Message-ID (diff)
From: Markos Chandras <Markos.Chandras@imgtec.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org, Paul Burton <paul.burton@imgtec.com>
Subject: Re: [PATCH 3/5] MIPS: Set page size to 16KB for malta SMP defconfigs
Date: Mon, 3 Mar 2014 14:06:18 +0000 [thread overview]
Message-ID: <53148C5A.7020101@imgtec.com> (raw)
Message-ID: <20140303140618.WlDpawrRUtmblDLyP5PgPU4-tC-qvOqcEq6A5HPzDQM@z> (raw)
In-Reply-To: <20140221173829.GI19285@linux-mips.org>
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
next prev parent reply other threads:[~2014-03-03 14:05 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-20 14:00 [PATCH 0/5] Update Malta defconfigs Markos Chandras
2014-02-20 14:00 ` Markos Chandras
2014-02-20 14:00 ` [PATCH 1/5] MIPS: regenerate malta defconfigs Markos Chandras
2014-02-20 14:00 ` Markos Chandras
2014-02-20 14:00 ` [PATCH 2/5] MIPS: Malta: Enable DEVTMPFS Markos Chandras
2014-02-20 14:00 ` Markos Chandras
2014-02-20 14:00 ` [PATCH 3/5] MIPS: Set page size to 16KB for malta SMP defconfigs Markos Chandras
2014-02-20 14:00 ` Markos Chandras
2014-02-21 17:38 ` Ralf Baechle
2014-03-03 14:06 ` Markos Chandras [this message]
2014-03-03 14:06 ` Markos Chandras
2014-03-03 14:29 ` Paul Burton
2014-03-03 14:29 ` Paul Burton
2014-03-04 17:01 ` Ralf Baechle
2014-03-03 22:24 ` Aaro Koskinen
2014-03-03 23:03 ` David Daney
2014-03-10 13:55 ` Aurelien Jarno
2014-03-10 17:42 ` David Daney
2014-02-20 14:00 ` [PATCH 4/5] MIPS: Default NR_CPUS=8 " Markos Chandras
2014-02-20 14:00 ` Markos Chandras
2014-02-20 14:00 ` [PATCH 5/5] MIPS: Add defconfig for Malta SMVP with EVA Markos Chandras
2014-02-20 14:00 ` Markos Chandras
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