From: Linh Dang <linh@linhdang.home>
To: linuxppc-embedded@lists.linuxppc.org
Subject: Re: BAT mapping exported to user-space
Date: Mon, 26 Jul 2004 14:33:27 -0400 [thread overview]
Message-ID: <wn5ekmysjns.fsf@linhd-2.ca.nortel.com> (raw)
In-Reply-To: <EB9CAD60-DF2E-11D8-910D-003065F9B7DC@embeddededge.com> (Dan Malek's message of "Mon, 26 Jul 2004 14:09:22 -0400")
Dan Malek <dan@embeddededge.com> wrote:
>
> On Jul 26, 2004, at 1:20 PM, Linh Dang wrote:
>
>> - has it been discussed/comptemplate/done before?
>
> Of course. Use mmap(), either on /dev/mem directly, or more
> preferable through a simple device driver for your ASIC that
> could also do simple system protection.
>
> Please don't be making such memory mapping kernel
> modifications. It will only cause future trouble.
>
> -- Dan
My understanding is:
- mmap(2) uses pages to map the device (my platform doesn't have large page.)
- mapping a large address range (hundreds-of-megabytes) is much more
efficient with BATs than with pages.
So, do you mean:
- mmap(2) can use BATs? or
- the difference in performance is negligible between BATs and
pages when mapping an address range of 200MBs?
Thanx
--
Linh Dang
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2004-07-26 18:33 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-07-26 17:20 BAT mapping exported to user-space Linh Dang
2004-07-26 18:09 ` Dan Malek
2004-07-26 18:33 ` Linh Dang [this message]
2004-07-27 1:18 ` Dan Malek
2004-07-27 2:27 ` Linh Dang
2004-07-27 16:36 ` Dan Malek
2004-07-27 17:34 ` Dang, Linh [CAR:2X23:EXCH]
2004-07-27 18:02 ` Dan Malek
2004-07-27 19:32 ` Linh Dang
2004-07-27 20:09 ` Dan Malek
2004-07-28 8:12 ` Oliver Korpilla
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