From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 5 Aug 2001 13:20:41 -0700 (PDT) From: Linus Torvalds Subject: Re: [RFC][DATA] re "ongoing vm suckage" In-Reply-To: <996985193.982.7.camel@gromit> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Michael Rothwell Cc: Mike Black , Ben LaHaise , Daniel Phillips , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton List-ID: On 5 Aug 2001, Michael Rothwell wrote: > > Could there be both interactive and throughput optimizations, and a > way to choose one or the other at run-time? Or even just at compile > time? Quite frankly, that's in my opinion the absolute worst approach. Yes, it's an approach many systems take - put the tuning load on the user, and blame the user if something doesn't work well. That way you don't have to bother with trying to get the code right, or make it make sense. In general, I think we can get latency to acceptable values, and latency is the _hard_ thing. We seem to have become a lot better already, by just removing the artificial ll_rw_blk code. Getting throughput up to where it should be should "just" be a matter of making sure we get nicely overlapping IO going. We probably just have some silly bug tht makes us hickup every once in a while and not keep the queues full enough. My current suspect is the read-ahead code itself being a bit too inflexible, but.. Linus -- 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/