From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from wx-out-0102.google.com (wx-out-0102.google.com [66.249.82.201]) by ozlabs.org (Postfix) with ESMTP id 2E1E1679E6 for ; Mon, 8 May 2006 22:43:48 +1000 (EST) Received: by wx-out-0102.google.com with SMTP id h29so788963wxd for ; Mon, 08 May 2006 05:43:47 -0700 (PDT) Message-ID: Date: Mon, 8 May 2006 08:36:43 -0400 From: "Ralph Blach" To: "moris dong" Subject: Re: Large Page Support, 2.6 kernel , PPC440 In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_38490_32197939.1147091803918" References: Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , ------=_Part_38490_32197939.1147091803918 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Morris, A long time ago, I did this for a 405 and it involves much more than just changing the page shift. >>From my memory, I will give you what I think you have to do. 1)you must go into tlb handling code and change it. That is in the header file 44x.S i beleive. 2)You have to change the pte directory sizes 3)You have to chage the linker script. 4)You have to change the size of the zero page. 5)you have to chage dcache flush routines, to cover the new page size. You have to find where 4096/4095 is hard coded as the page size and change it. This is no small job, and what you come up with will be very unsupported. I beleive If you pin the kerel TLB you might get the performance you need and this should be in the kernel config scripts. Good luck, Chip On 5/1/06, moris dong wrote: > > Friends, > My PPC440 (32bit) MMU supports multiple page sizes. > For the default 4K pages, my 2.6.11 kernel compiles and boots just fine. > I want to re-build it with large pages, to improve my application > performance. > I tried modifying PAGE_SHIFT in "page.h" to 13 (8K pages) and re-build my > kernel. > Compilation worked out fine, but my kernel does NOT boot, nor it prints > anything to the console. > > Has anyone successfully compiled & booted a 2.6 kernel with pages larger > than 4K ? > What am I doing wrong ? > > Thanks a lot. > > _________________________________________________________________ > Express yourself instantly with MSN Messenger! Download today it's FREE! > http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/ > > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded > ------=_Part_38490_32197939.1147091803918 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Morris,

A long time ago, I did this for a 405 and it involves much m= ore than just changing the page shift.

From my memory, I will give y= ou what I think you have to do.
1)you must go into tlb handling code and= change it.  That is in the=20
header file 44x.S i beleive.
2)You have to change the pte directory = sizes
3)You have to chage the linker script.
4)You have to change the= size of the zero page.
5)you have to chage dcache flush routines, to co= ver the new page size.
You have to find where 4096/4095 is hard coded as the page size and cha= nge it.

This  is no small job, and what you come up with will b= e very unsupported.
I beleive If you pin the kerel TLB you might get the performance you need and this should be in the kernel config scripts.
Good luck,

Chip

On 5/= 1/06, moris dong < moris_dong@hotmail.com> wrote:
Friends,
My PPC440 (32bit) MMU supports multi= ple page sizes.
For the default 4K pages, my 2.6.11 kernel compiles and boots just fine= .
I want to re-build it with large pages, to improve my application
p= erformance.
I tried modifying PAGE_SHIFT in "page.h" to 13 (8K= pages) and re-build my
kernel.
Compilation worked out fine, but my kernel does NOT boot, no= r it prints
anything to the console.

Has anyone successfully comp= iled & booted a 2.6 kernel with pages larger
than 4K ?
What am I = doing wrong ?

Thanks a lot.

______________________________________________= ___________________
Express yourself instantly with MSN Messenger! Downl= oad today it's FREE!
http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/

= _______________________________________________
Linuxppc-embedded mailin= g list
Linuxppc-embedded= @ozlabs.org
h= ttps://ozlabs.org/mailman/listinfo/linuxppc-embedded

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