Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 29 Aug 2002 16:49:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 29 Aug 2002 16:49:16 -0400 Received: from holly.csn.ul.ie ([136.201.105.4]:33548 "HELO holly.csn.ul.ie") by vger.kernel.org with SMTP id ; Thu, 29 Aug 2002 16:49:16 -0400 Date: Thu, 29 Aug 2002 21:53:32 +0100 (IST) From: Mel Gorman X-X-Sender: mel@skynet To: Daniel Phillips Cc: linux-mm@kvack.org, Subject: Re: 2.4.19 Vs 2.4.19-rmap14a with anonymous mmaped memory In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1873 Lines: 46 On Thu, 29 Aug 2002, Daniel Phillips wrote: > The perl script that writes tables isn't too informative without knowing > how the tables are used. Pseudocode that says exactly what your final > reference pattern is would be a lot more useful. I guessed that after I thought about it for a while and reworked the algorithm for 0.7. To make things easier again, I added a new graph to the reports which is in 0.7 called "Page Index Reference over Time" see http://www.csn.ul.ie/~mel/projects/vmregress/output_sample/mmap/read/25000/mapanon.html It is the second graph. At the beginning, it is at the 0th page and it moves through the address space over time. A totally random one would make this graph look like noise. The graph should give a good idea how memory was referenced. In 0.6 and with these tests, it would have been a similar curve except the last page would have been hit around 40000 references before the end of the test. After that, the pages were referenced in a linear pattern which was a mistake after reviewing it a bit. If people are still interested, I'll run a full set of tests again on 2.4.19 and 2.4.19-rmap14a with 0.7 and post up the results complete with the page reference information so you don't have to guess this time. It takes about a full day to run a complete series. Any taker? > It would also be useful to state what you define as a reference. A user > space program read-accesses a single byte from some address? > A reference in this test was reading a full page of information using copy_from_user() -- Mel Gorman MSc Student, University of Limerick http://www.csn.ul.ie/~mel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/