From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 25 Sep 2000 15:10:51 +0200 (CEST) From: Ingo Molnar Reply-To: mingo@elte.hu Subject: Re: [patch] vmfixes-2.4.0-test9-B2 In-Reply-To: <20000925145856.A13011@athlon.random> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: Linus Torvalds , Rik van Riel , Roger Larsson , MM mailing list , linux-kernel@vger.kernel.org List-ID: On Mon, 25 Sep 2000, Andrea Arcangeli wrote: > > yet another elevator algorithm we need a squeaky clean VM balancer above > > FYI: My current tree (based on 2.4.0-test8-pre5) delivers 16mbyte/sec > in the tiobench write test compared to clean 2.4.0-test8-pre5 that > delivers 8mbyte/sec great! I'm happy we have a fine-tuned elevator again. > Also I I found the reason of your hang, it's the TASK_EXCLUSIVE in > wait_for_request. The high part of the queue is reserved for reads. > Now if a read completes and it wakeups a write you'll hang. yep. But i dont understand why this makes any difference - the waitqueue wakeup is FIFO, so any other request will eventually arrive. Could you explain this bug a bit better? > If you think I should delay those fixes to do something else I don't > agree sorry. no, i never ment it. I find it very good that those half-done changes are cleaned up and the remaining bugs / performance problems are eliminated - the first reports about bad write performance came right after the original elevator patches went in, about 6 months ago. 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.eu.org/Linux-MM/