From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 20 May 2000 08:52:21 +0200 From: Carlo Wood Subject: VM and classzone Message-ID: <20000520085221.A8294@a2000.nl> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: ; from andrea@suse.de on Fri, May 19, 2000 at 09:16:35AM -0700 Sender: owner-linux-mm@kvack.org Return-Path: To: linux-kernel@vger.rutgers.edu Cc: linux-mm@kvack.org, torvalds@transmeta.com, riel@conectiva.com.br, andrea@suse.de List-ID: On Fri, May 19, 2000 at 09:16:35AM -0700, Andrea Arcangeli wrote: > On Fri, 19 May 2000, Rik van Riel wrote: > > >varying loads (but that's orthagonal, except for the fact > >that it would automagically solve the last 2 problems with > >pre9-2 + quintela). > > This make no sense to me. It it fixes two problems that doesn't mean it's > not orthogonal. > > I'm not sure about the problems you're talking about. And I'm not > convinced that waiting I/O completation during shink_mmap will be > successfully. > > Andrea I know I am pretty new to this list, but allow me to put an observation into a summary: The were problems with VM - also known as 'kswapd problem' because it showed itself mainly as a stall of the kernel while kswapd was consuming often, and a lot, cpu. Andrea Arcangeli has been working on what is known as the "class zone" patch(es) - which is a structural redesign related to how VM works (correct me if I am wrong). Linus didn't add this to the kernel because he thinks that Andreas (re)design has flaws. Rik van Riel also worked on VM, but more from the point of view of 'how to fix the kswapd bug', and he succeeded (at least partly, perhaps completely): reports have been posted that this bug is now gone - which is also my own humble observation. Nevertheless, the discussion about Andreas design continues as if it had to do with the bug - which is not true (I agree with Linus on this). In order to come to a solution, I'd like to suggest the following: - Linus makes a short list of what he thinks are the pros and cons of Andreas design, so it is more clear to Andrea what is the reason for the rejection so far; and if his design will ever make a chance to get into the kernel at all. - If there is chance that after possible improvements the patch will be added to a future kernel, then a series of benchmark tests if proposed by all parties that will produce *numbers* - so we will be able to actually see the impact of Andreas patch (with and without). $0.02 of a neutral party, -- Carlo Wood -- 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/