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Date: Wed, 11 Jul 2001 06:43:55 +1200
From: Chris Wedgwood <cw@f00f.org>
To: Brian Gerst <bgerst@didntduck.org>
Cc: Jesse Pollard <pollard@tomcat.admin.navo.hpc.mil>, ttabi@interactivesi.com,
        linux-kernel@vger.kernel.org
Subject: Re: What is the truth about Linux 2.4's RAM limitations?
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On Tue, Jul 10, 2001 at 02:28:54PM -0400, Brian Gerst wrote:

    Jesse Pollard wrote:

        > If the entire page table were given to a user, then a full cache
        > flush would have to be done on every context switch and system
        > call. That would be very slow, but would allow a full 4G address
        > for the user.

    A full cache flush would be needed at every entry into the kernel,
    including hardware interrupts.  Very poor for performance.

Why would a cache flush be necessary at all? I assume ia32 caches
where physically not virtually mapped?




   --cw
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