From: Arjan van de Ven <arjanv@redhat.com>
To: Linh Dang <linhd@nortel.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: mmap (2) vs read (2)
Date: Sat, 17 Sep 2005 14:26:35 -0400 [thread overview]
Message-ID: <1126981595.3010.1.camel@localhost.localdomain> (raw)
In-Reply-To: <wn58xxvhdz8.fsf@linhd-2.ca.nortel.com>
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On Sat, 2005-09-17 at 12:10 -0400, Linh Dang wrote:
> Hi, how come reading memory from /dev/mem using pread(2) or mmap(2)
> will give diffent results?
because you're being evil ;)
mmap of /dev/mem for *ram* is special. To avoid cache aliases and other
evils, you can only mmap non-ram realistically on /dev/mem.
Why are you using /dev/mem in the first place, it's a sure sign that
you're doing something really wrong in your design...
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next prev parent reply other threads:[~2005-09-17 20:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-17 16:10 mmap (2) vs read (2) Linh Dang
2005-09-17 18:26 ` Arjan van de Ven [this message]
2005-09-18 16:47 ` Linh Dang
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