From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3D26304C.51FAE560@zip.com.au> Date: Fri, 05 Jul 2002 16:48:28 -0700 From: Andrew Morton MIME-Version: 1.0 Subject: Re: vm lock contention reduction References: <3D24F869.2538BC08@zip.com.au> <3D2501FA.4B14EB14@zip.com.au> <20020705231113.GA25360@holomorphy.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: William Lee Irwin III Cc: Rik van Riel , Andrea Arcangeli , "linux-mm@kvack.org" , Linus Torvalds List-ID: William Lee Irwin III wrote: > > On Thu, Jul 04, 2002 at 07:18:34PM -0700, Andrew Morton wrote: > > Of course, that change means that we wouldn't be able to throttle > > page allocators against IO any more, and we'd have to do something > > smarter. What a shame ;) > > This is actually necessary IMHO. Some testing I've been able to do seems > to reveal the current throttling mechanism as inadequate. > I don't think so. If you're referring to the situation where your 4G machine had 3.5G dirty pages without triggering writeback. That's not a generic problem. It's something specific to your setup. You're going to have to repeat it and stick some printk's into balance_dirty_pages(). No other way of finding it. Possibly it's an arith overflow in there, but I more suspect that your nr_pagecache_pages() function is returning an incorrect value. This happened to David M-T just this week in the 2.4 kernel - the nr_buffermem_pages() function was returning a bad value due to an unaccounted-for hole in the memory map and the observed effect was just the same. So. Please debug it. - -- 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/