From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 360436B0011 for ; Wed, 27 Apr 2011 17:42:24 -0400 (EDT) Message-ID: <4DB88DAF.2010504@freescale.com> Date: Wed, 27 Apr 2011 16:42:07 -0500 From: Timur Tabi MIME-Version: 1.0 Subject: Re: [PATCH 2/3] make new alloc_pages_exact() References: <20110414200139.ABD98551@kernel> <20110414200140.CDE09A20@kernel> <4DB88AF0.1050501@freescale.com> <1303940249.9516.366.camel@nimitz> In-Reply-To: <1303940249.9516.366.camel@nimitz> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andi Kleen , Mel Gorman , Andrew Morton , Michal Nazarewicz , David Rientjes Dave Hansen wrote: >> Is there an easy way to verify that alloc_pages_exact(5MB) really does allocate >> > only 5MB and not 8MB? > I'm not sure why you're asking. How do we know that the _normal_ > allocator only gives us 4k when we ask for 4k? Well, that's just how it > works. If alloc_pages_exact() returns success, you know it's got the > amount of memory that you asked for, and only that plus a bit of masking > for page alignment. > > Have you seen alloc_pages_exact() behaving in some other way? I've never tested this part of alloc_pages_exact(), even when I wrote (the first version of) it. I just took it on faith that it actually did what it was supposed to do. -- Timur Tabi Linux kernel developer at Freescale -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org