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From: Daniel Gryniewicz <dang@fprintf.net>
To: Brian McGrew <Brian@doubledimension.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Help with mapping memory into kernel space?
Date: Wed, 18 Aug 2004 11:30:15 -0400	[thread overview]
Message-ID: <1092843015.14961.2.camel@localhost> (raw)
In-Reply-To: <E6456D527ABC5B4DBD1119A9FB461E3501E00B@constellation.doubledimension.com>

On Tue, 2004-08-17 at 22:39 -0700, Brian McGrew wrote:
> Good day All:
> 

<snip>

> The overall problem is that the more system memory we install,
> the fewer IBB's we can use.  For instance, 256MB lets us use
> four IBB's; 512MB lets us use three IBB's and so on.  Basicly,
> the kernel blows up trying to map memory.  Each IBB has two
> banks of 64MB of RAM on them which we try and memmap to system
> memory for speed of addressing.  So essentaily, we're sending
> out four camera systems with only 256MB of memory which is only
> about one quarter of what we need.

On x86, the kernel has 1 GiB of address space.  Try the 2G/2G split
patches, or the 4G/4G patches, either one of which should increase your
kernel address space enough to map both memory and your buffers.

Daniel

  parent reply	other threads:[~2004-08-18 15:30 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-08-18  5:39 Help with mapping memory into kernel space? Brian McGrew
2004-08-18  7:31 ` William Lee Irwin III
2004-08-18 11:16   ` Mark Hounschell
2004-08-18 20:27     ` William Lee Irwin III
2004-08-18 15:30 ` Daniel Gryniewicz [this message]
2004-08-18 15:59   ` Richard B. Johnson

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