[Top] [All Lists]

Re: sparse or discontiguous memory on 32bit mips platform

To: "Sundius, Michael" <>
Subject: Re: sparse or discontiguous memory on 32bit mips platform
From: "Jon Fraser" <>
Date: Mon, 14 Jul 2008 12:58:58 -0400
In-reply-to: <>
Organization: Broadcom
Original-recipient: rfc822;
References: <>

I have something similar.  Under 2.6.24, I have the following


Each bank of memory is in a separate node. I did have to write
some code in arch/mips/kernel/setup.c to setup the multiple memory
regions.  I used some of the PPC NUMA code as an example, IIRC.

Because my second bank of mem starts at 0x20000000,
I use HIGHMEM to access it.  There been some HIGHMEM info
posted to this list in the last 6 months.

I didn't think my efforts were general enough to post, but maybe
more people are doing these discontiguous memory platforms.


On Mon, 2008-07-14 at 09:30 -0700, Sundius, Michael wrote:
> Hi,
> I'm looking into turning on either sparse memory or discontiguous
> memory for a 32 Mips platform (single processor) since we have 2
> large memory banks that are nowhere near each other in physical
> memory.
> What has been done in hardware, has been done and so be it.
> But since we are an embedded system, we do have memroy constraints and
> wish to conserve as much space as possible, we are trying to avoid
> creating
> pagetables for the whole space.
> That said, I have a few questions.
> 1) Are there any 32 Mips platforms where either sparsemem or
> discontigmem have been supported?
> 2) It seems like sparesemem is the wave of the future, am I
> correct in assuming that this is simmplier / more efficient /
> "better" way to go?
> 3) Is there anywhere (besides the code) where I can find an article
> or some documentation on how sparsemem and/or discontig work? or how
> to go about adding support for them in a here to for unsupported
> platform?
> all info, pointers, hints, advice and comments are much appreciated.
> thanks
> Mike
> ______________________________________________________________________
>       - - - - -                              Cisco
> - - - - -         
> This e-mail and any attachments may contain information which is
> confidential, 
> proprietary, privileged or otherwise protected by law. The information
> is solely 
> intended for the named addressee (or a person responsible for
> delivering it to 
> the addressee). If you are not the intended recipient of this message,
> you are 
> not authorized to read, print, retain, copy or disseminate this
> message or any 
> part of it. If you have received this e-mail in error, please notify
> the sender 
> immediately by return e-mail and delete it from your computer.

<Prev in Thread] Current Thread [Next in Thread>