From: Russell King <rmk@arm.linux.org.uk>
To: Nick Piggin <npiggin@suse.de>
Cc: Martin Schwidefsky <martin.schwidefsky@de.ibm.com>,
carsteno@linux.vnet.ibm.com,
Heiko Carstens <h.carstens@de.ibm.com>,
Jared Hulbert <jaredeh@gmail.com>,
Linux Memory Management List <linux-mm@kvack.org>,
linux-arch@vger.kernel.org
Subject: Re: [rfc][patch] mm: use a pte bit to flag normal pages
Date: Mon, 7 Jan 2008 10:30:29 +0000 [thread overview]
Message-ID: <20080107103028.GA9325@flint.arm.linux.org.uk> (raw)
In-Reply-To: <20080107044355.GA11222@wotan.suse.de>
On Mon, Jan 07, 2008 at 05:43:55AM +0100, Nick Piggin wrote:
> We initially wanted to do the whole vm_normal_page thing this way, with
> another pte bit, but we thought there were one or two archs with no spare
> bits. BTW. I also need this bit in order to implement my lockless
> get_user_pages, so I do hope to get it in. I'd like to know what
> architectures cannot spare a software bit in their pte_present ptes...
ARM is going to have to use the three remaining bits we have in the PTE
to store the memory type to resolve bugs on later platforms. Once they're
used, ARM will no longer have any room for any further PTE expansion.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of:
next prev parent reply other threads:[~2008-01-07 10:32 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20071221104701.GE28484@wotan.suse.de>
[not found] ` <OFEC52C590.33A28896-ONC12573B8.0069F07E-C12573B8.006B1A41@de.ibm.com>
2008-01-07 4:43 ` [rfc][patch] mm: use a pte bit to flag normal pages Nick Piggin
2008-01-07 10:30 ` Russell King [this message]
2008-01-07 11:14 ` Nick Piggin
2008-01-07 18:49 ` Jared Hulbert
2008-01-07 19:45 ` Russell King
2008-01-07 22:52 ` Jared Hulbert
2008-01-08 2:37 ` Andi Kleen
2008-01-08 2:49 ` Nick Piggin
2008-01-08 3:31 ` Andi Kleen
2008-01-08 3:52 ` Nick Piggin
2008-01-08 10:11 ` Catalin Marinas
2008-01-08 10:52 ` Russell King
2008-01-08 13:54 ` Catalin Marinas
2008-01-08 14:08 ` Russell King
2008-01-10 13:33 ` Carsten Otte
2008-01-10 23:18 ` Nick Piggin
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