From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 26 May 2000 18:36:40 +0200 From: Jamie Lokier Subject: Re: [RFC] 2.3/4 VM queues idea Message-ID: <20000526183640.A21731@pcep-jamie.cern.ch> References: <200005242057.NAA77059@apollo.backplane.com> <20000525115202.A19969@pcep-jamie.cern.ch> <200005251618.JAA82894@apollo.backplane.com> <20000525185059.A20563@pcep-jamie.cern.ch> <20000526120805.C10082@redhat.com> <20000526132219.C21510@pcep-jamie.cern.ch> <20000526141526.E10082@redhat.com> <20000526163129.B21662@pcep-jamie.cern.ch> <20000526153821.N10082@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20000526153821.N10082@redhat.com>; from sct@redhat.com on Fri, May 26, 2000 at 03:38:21PM +0100 Sender: owner-linux-mm@kvack.org Return-Path: To: "Stephen C. Tweedie" Cc: Matthew Dillon , Rik van Riel , linux-mm@kvack.org List-ID: Stephen C. Tweedie wrote: > > mremaps that simply expand or shrink a segment are fine by themselves. > > mremaps that move a segment are fine by themselves. > > No, they are not fine. When you move a segment, you end up with pages > which have the same offset but are now at a different VA. What that > means is that you have no way of finding out, for a given physical page, > what the VA of all of the mappings of that page may be. That means that > you have no way to find all of the ptes short of scanning all the vmas > in order. That's ok. VA == vma->pgoff + page_offset. Move a vma and that's still true. The ptes are found by looking at the list of all vmas referring to all the address_spaces that refer to a page. -- Jamie -- 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.eu.org/Linux-MM/