From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 06 Apr 2003 15:03:03 -0700 From: "Martin J. Bligh" Subject: Re: subobj-rmap Message-ID: <1600000.1049666582@[10.10.2.4]> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: Alan Cox , Andrew Morton , andrea@suse.de, mingo@elte.hu, hugh@veritas.com, dmccr@us.ibm.com, Linux Kernel Mailing List , linux-mm@kvack.org, Bill Irwin List-ID: >> Supposing we keep a list of areas (hung from the address_space) that >> describes independant linear ranges of memory that have the same set >> of vma's mapping them (call those subobjects). Each subobject has a >> chain of vma's from it that are mapping that subobject. >> >> address_space ---> subobject ---> subobject ---> subobject ---> subobject >> | | | | >> v v v v >> vma vma vma vma >> | | | >> v v v >> vma vma vma >> | | >> v v >> vma vma > > OK, lets say we have a file of 1000 pages, or > offsets 0 to 999, with the following mappings: > > VMA A: 0-999 > VMA B: 0-200 > VMA C: 150-400 > VMA D: 300-500 > VMA E: 300-500 > VMA F: 0-999 > > How would you describe these with independant regions ? Good question to illustrate with. Extra spacing added just for ease of reading: 0-150 -> 150-200 -> 200-300 -> 300-400 -> 400-500 -> 500-999 A A A A A A B B C C C D D E E F F F F F F > For VMAs D & E and A & F it's a no-brainer, > but for Oracle shared memory you shouldn't > assume that you have any similar mappings We can always leave the sys_remap_file_pages stuff using pte_chains, and should certainly do that at first. But doing it for normal stuff should be less controversial, I think. M. -- 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: aart@kvack.org