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From: Andi Kleen <ak@suse.de>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: akpm@osdl.org, linux-kernel@vger.kernel.org,
	benh@kernel.crashing.org, anton@samba.org, paulus@samba.org,
	linuxppc64-dev@lists.linuxppc.org
Subject: Re: RFC: COW for hugepages
Date: Wed, 7 Apr 2004 14:34:47 +0200	[thread overview]
Message-ID: <20040407143447.4d8f08af.ak@suse.de> (raw)
In-Reply-To: <20040407074239.GG18264@zax>

On Wed, 7 Apr 2004 17:42:39 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> Currently the kernel does not implement copy-on-write for huge pages -
> in fact any sort of page fault on a hugepage results in a SIGBUS.
> This means that hugepages *always* have MAP_SHARED semantics, even if
> MAP_PRIVATE is requested, and in particular that they are always
> shared across a fork().  Particularly when using hugetlbfs as just a
> source of quasi-anonymous memory, those are rather strange semantics.

[...]

Implementing this for ppc64 only is just wrong. Before you do this 
I would suggest to factor out the common code in the various hugetlbpage
implementations and then implement it in common code.

-Andi

  parent reply	other threads:[~2004-04-07 12:34 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-04-07  7:42 RFC: COW for hugepages David Gibson
2004-04-07  7:53 ` Andrew Morton
2004-04-07  8:03   ` Anton Blanchard
2004-04-07  8:29   ` Benjamin Herrenschmidt
2004-04-08  1:57     ` David Gibson
2004-04-07  9:00 ` Zoltan Menyhart
2004-04-08  1:53   ` David Gibson
2004-04-08 11:10     ` Zoltan Menyhart
2004-04-08 14:19       ` David Gibson
2004-04-07 12:34 ` Andi Kleen [this message]
2004-04-07 14:27   ` Anton Blanchard
2004-04-07 14:50     ` Andi Kleen
2004-04-07 21:41       ` Anton Blanchard
2004-04-07 21:47         ` Andi Kleen
2004-04-08  1:11   ` Benjamin Herrenschmidt
2004-04-08  2:01     ` Andrew Morton
2004-04-08  3:09       ` David Gibson
2004-04-08  3:24         ` Andrew Morton
2004-04-08  3:56           ` David Gibson
2004-04-08  1:50   ` David Gibson
2004-04-07 15:21 ` Dave Hansen
2004-04-08  3:22   ` David Gibson

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