From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from chiara.csoma.elte.hu (chiara.csoma.elte.hu [157.181.71.18]) by kvack.org (8.8.7/8.8.7) with ESMTP id CAA16823 for ; Sat, 5 Dec 1998 02:51:34 -0500 Date: Sat, 5 Dec 1998 08:51:13 +0100 (CET) From: MOLNAR Ingo Subject: Re: SWAP: Linux far behind Solaris or I missed something (fwd) In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Rik van Riel Cc: "Stephen C. Tweedie" , Neil Conway , Linux MM , Jean-Michel.Vansteene@bull.net, "linux-kernel@vger.rutgers.edu" List-ID: On Fri, 4 Dec 1998, Rik van Riel wrote: > > I know. That's why relying on fixed margins to ensure good > > performance is wrong: the system really ought to be self-tuning. > > We may yet get it right for 2.2: there are people working on this. > > It appears that 2.1.130 + my little patches only needs the > borrow percentage (otherwise kswapd doesn't have enough > reason to switch from the always-succesful swap_out()), > and that only needs to be set to a high value... 'borrow percentage' is just yet another arbitrary parameter (*). The solution is not to increase the number of parameters and tweak them until there is more or less ok fit on all testcases! (i know that borrow percentage was there originally) The task is to _decrease_ the number of parameters as much as possible. (preferably no 'number' parameters at all, just one basic self-tuning framework) [Unfortunately this is much much harder than adding parameters, it needs a thorough understanding of all issues involved.] -- mingo (*) parameter: degree of freedom in an algorithm, both kernel-source compiled-in constants/tweaks/rules and user-supplied (possibly runtime) parameters. -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org