From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 28 Dec 2002 08:39:12 +0100 (CET) From: Ingo Molnar Reply-To: Ingo Molnar Subject: Re: shared pagetable benchmarking In-Reply-To: <3E0D4B83.FEE220B8@digeo.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Linus Torvalds , "Martin J. Bligh" , Dave McCracken , Daniel Phillips , linux-mm@kvack.org List-ID: On Fri, 27 Dec 2002, Andrew Morton wrote: > Yup. Ingo said at the time: > > It would be faster to iterate the pagecache mapping's radix tree > and the pagetables at once, but it's also *much* more complex. I have > tried to implement it and had to unroll the change - mixing radix tree > walking and pagetable walking and getting all the VM details right is > really complex - especially considering all the re-lookup race checks > that have to occur upon IO. > > But find_get_pages() is well-suited to this, and was not in place when > he did this work. i agree that find_get_pages() would simplify this work. I did not consider group-lookup - i tried to implement an algorithm that had a single-page scope, to keep the amount of locked pages to the minimum. Ingo -- 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/