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From: Anton Blanchard <anton@samba.org>
To: "Sexton, Matt" <sexton@mc.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: inconsistent mmap and get_user_pages with hugetlbfs on ppc64
Date: Sun, 18 Sep 2005 21:22:12 +1000	[thread overview]
Message-ID: <20050918112212.GD17639@krispykreme> (raw)
In-Reply-To: <92CB67C83EE773499A7F2F6EA7E3FC940F0E99@ad-email1.ad.mc.com>


Hi,

> On a ppc64 platform running 2.6.13-1, the virtual to physical mapping
> established by mmap'ing a hugetlbfs file does not seem to match the
> mapping described by get_user_pages().

I just tried a simple test - I created a program that allocated a
hugetlb page and wrote some stuff in it. I then attached with gdb and
dumped memory at that address and things came out OK.

That should have exercised the ptrace -> access_process_vm -> get_user_pages
path. So at least for this case get_user_pages seems to be working :)

It would be useful to simplify your problem a bit and take DMA out of
the picture. Moving this over to linuxppc64-dev@ozlabs.org would also
make sense.

Anton

  reply	other threads:[~2005-09-18 11:23 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-09-16 22:52 inconsistent mmap and get_user_pages with hugetlbfs on ppc64 Sexton, Matt
2005-09-18 11:22 ` Anton Blanchard [this message]
2005-09-29 17:50 ` Adam Litke

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