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From: "Andreas Block" <andreas.block@esd-electronics.com>
To: linux-kernel@vger.kernel.org
Subject: Re: Bad page state with x86_64
Date: Wed, 27 Sep 2006 09:20:48 +0200	[thread overview]
Message-ID: <op.tgiz0y0t8n9ctc@pc-block.esd> (raw)
In-Reply-To: <4519200A.4000109@yahoo.com.au>

On Tue, 26 Sep 2006 14:41:46 +0200, Nick Piggin <nickpiggin@yahoo.com.au>
wrote:

> It is freeing a PageReserved page. You should ensure to balance your
> reference counting on *each* page (or allocate a compound page and
> treat it as a single one). When you map pages into userspace via
> nopage or remap_pfn_range, you need to increment their count, which
> gets decremented by the VM when they are unmapped.

Thanks a lot for your time and help. Still there are a few things a
seemingly don't understand correctly.
Do I understand you right, I don't have to "put_page" after calling
"get_page" in my no-page handler?
Also I'm wondering, why this code works flawlessly on 2.6.10 32-Bit and
several 2.4.x kernels 32-Bit and PPC and is failing to work on x86_64,
only. Do I have to do the "get/put_page" mechanism differnetly on x86_64?
Another question:
In my no-page handler, I reserve the physical page. I do have to clear the
reserve bit of those page after unmap, right? Or is this done implicitly
as well?

Again, thanks for your effort.
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      reply	other threads:[~2006-09-27  7:24 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-09-26 10:18 Andreas Block
2006-09-26 12:41 ` Nick Piggin
2006-09-27  7:20   ` Andreas Block [this message]

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