public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Milton Miller <miltonm@bga•com>
To: Yuri Tikhonov <yur@emcraft•com>
Cc: wd@denx•de, dzu@denx•de, linuxppc-dev@ozlabs•org,
	paulus@samba•org, hugh@veritas•com, akpm@linux-foundation•org,
	prodyuth@gmail•com, yanok@emcraft•com
Subject: Re: [PATCH][v4] powerpc 44x: support for 256KB PAGE_SIZE
Date: Fri, 16 Jan 2009 09:00:33 -0600	[thread overview]
Message-ID: <f341f40f2bfa0818be32a86da62ada9b@bga.com> (raw)
In-Reply-To: <200901130149.43588.yur@emcraft.com>

On Jan 12, 2009, at 4:49 PM, Yuri Tikhonov wrote:

> This patch adds support for 256KB pages on ppc44x-based boards.

Another day, another comment.  The motivation for reply was the second 
comment below.

>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 84b8613..18f33ef 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -443,6 +443,19 @@ config PPC_64K_PAGES
>  	bool "64k page size" if 44x || PPC_STD_MMU_64
>  	select PPC_HAS_HASH_64K if PPC_STD_MMU_64
>
> +config PPC_256K_PAGES
> +	bool "256k page size" if 44x
> +	depends on !STDBINUTILS && !SHMEM

depends on !STDBINUTILS && (!SHMEM || BROKEN)

to identify that it is not fundamentally incompatable just not a chance 
of working without other changes.

> +	help
> +	  Make the page size 256k.
> +
> +	  As the ELF standard only requires alignment to support page
> +	  sizes up to 64k, you will need to compile all of your user
> +	  space applications with a non-standard binutils settings
> +	  (see the STDBINUTILS description for details).
> +
> +	  Say N unless you know what you are doing.
> +
>  endchoice
>
>  config FORCE_MAX_ZONEORDER


> diff --git a/arch/powerpc/platforms/44x/Kconfig 
> b/arch/powerpc/platforms/44x/Kconfig
> index 3496bc0..d02e8c8 100644
> --- a/arch/powerpc/platforms/44x/Kconfig
> +++ b/arch/powerpc/platforms/44x/Kconfig
> @@ -214,6 +214,18 @@ config 440SPe
>  	bool
>  	select IBM_NEW_EMAC_EMAC4
>
> +config STDBINUTILS
> +	bool "Using standard binutils settings"
> +	depends on 44x
> +	default y


I think this should be

config STDBINUTILS
	bool "Using standard binutils settings" if 44x
	default y

that way we imply that all powerpc users are using the standard 
binutils instead of only those using a 44x platform.  We still get the 
intended effect of asking the user only on 44x.

I haven't looked at the resulting question or config order to see if it 
makes sense to leave it here or put it closer to the page size.


> +	help
> +	  Turning this option off allows you to select 256KB PAGE_SIZE on 
> 44x.
> +	  Note, that kernel will be able to run only those applications,
> +	  which had been compiled using binutils later than 2.17.50.0.3 with
> +	  '-zmax-page-size' set to 256K (the default is 64K). Or, if using
> +	  the older binutils, you can patch them with a trivial patch, which
> +	  changes the ELF_MAXPAGESIZE definition from 0x10000 to 0x40000.
> +
>  config 460EX
>  	bool
>  	select PPC_FPU
> -- 
> 1.6.0.6

milton

  reply	other threads:[~2009-01-16 14:54 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-12 22:49 [PATCH][v4] powerpc 44x: support for 256KB PAGE_SIZE Yuri Tikhonov
2009-01-16 15:00 ` Milton Miller [this message]
2009-01-16 15:18   ` Re[2]: " Yuri Tikhonov
2009-01-18  2:32     ` Milton Miller
2009-01-18 13:40       ` Josh Boyer
2009-01-29 11:40       ` Re[4]: " Yuri Tikhonov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=f341f40f2bfa0818be32a86da62ada9b@bga.com \
    --to=miltonm@bga$(echo .)com \
    --cc=akpm@linux-foundation$(echo .)org \
    --cc=dzu@denx$(echo .)de \
    --cc=hugh@veritas$(echo .)com \
    --cc=linuxppc-dev@ozlabs$(echo .)org \
    --cc=paulus@samba$(echo .)org \
    --cc=prodyuth@gmail$(echo .)com \
    --cc=wd@denx$(echo .)de \
    --cc=yanok@emcraft$(echo .)com \
    --cc=yur@emcraft$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox