From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 8 Jan 2001 13:57:00 +0000 From: "Stephen C. Tweedie" Subject: Re: Subtle MM bug Message-ID: <20010108135700.O9321@redhat.com> References: <200101080602.WAA02132@pizda.ninka.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from torvalds@transmeta.com on Sun, Jan 07, 2001 at 10:42:11PM -0800 Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds Cc: "David S. Miller" , Rik van Riel , Marcelo Tosatti , linux-mm@kvack.org List-ID: Hi, On Sun, Jan 07, 2001 at 10:42:11PM -0800, Linus Torvalds wrote: > > and just get rid of all the logic to try to "find the best mm". It's bogus > anyway: we should get perfectly fair access patterns by just doing > everything in round-robin Definitely. > Then, with something like the above, we just try to make sure that we scan > the whole virtual memory space every once in a while. Make the "every once > in a while" be some simple heuristic like "try to keep the active list to > less than 50% of all memory". ... which will produce an enormous storm of soft page faults for workloads involving mmaping large amounts of data or where we have a lot of space devoted to anonymous pages, such as static computational workloads. The idea of an inactive list target is sound, but it needs to be based on memory pressure: we don't need anything like 50% if we aren't under any pressure, so compute-bound workloads with large data sets can achieve stability. --Stephen -- 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/