From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [patch 4/6] mm: merge populate and nopage into fault (fixes nonlinear) From: Peter Zijlstra In-Reply-To: <20070307103842.GD5555@wotan.suse.de> References: <20070307004709.432ddf97.akpm@linux-foundation.org> <20070307010756.b31c8190.akpm@linux-foundation.org> <1173259942.6374.125.camel@twins> <20070307094503.GD8609@wotan.suse.de> <20070307100430.GA5080@wotan.suse.de> <1173262002.6374.128.camel@twins> <20070307102106.GB5555@wotan.suse.de> <1173263085.6374.132.camel@twins> <20070307103842.GD5555@wotan.suse.de> Content-Type: text/plain Date: Wed, 07 Mar 2007 11:47:42 +0100 Message-Id: <1173264462.6374.140.camel@twins> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Miklos Szeredi , akpm@linux-foundation.org, mingo@elte.hu, linux-mm@kvack.org, linux-kernel@vger.kernel.org, benh@kernel.crashing.org List-ID: On Wed, 2007-03-07 at 11:38 +0100, Nick Piggin wrote: > > > There are real users who want these fast, though. > > > > Yeah, why don't we have a tree per nonlinear vma to find these pages? > > > > wli mentions shadow page tables.. > > We could do something more efficient, but I thought that half the point > was that they didn't carry any of this extra memory, and they could be > really fast to set up at the expense of efficiency elsewhere. I'm failing to understand this :-( That extra memory, and apparently they don't want the inefficiency either. > I don't see it being a big deal. I doubt anybody is writing out huge > amounts of data via nonlinear mappings. Well, now they don't, but it could be done or even exploited as a DoS. -- 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/ . Don't email: email@kvack.org