Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 18 Jan 2002 11:59:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 18 Jan 2002 11:59:19 -0500 Received: from smtpde02.sap-ag.de ([194.39.131.53]:39842 "EHLO smtpde02.sap-ag.de") by vger.kernel.org with ESMTP id ; Fri, 18 Jan 2002 11:46:57 -0500 Message-ID: <3C485169.7070005@sap.com> Date: Fri, 18 Jan 2002 17:46:33 +0100 From: Wilhelm Nuesser User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.6) Gecko/20011120 X-Accept-Language: en-us MIME-Version: 1.0 To: Alan Cox CC: Andrea Arcangeli , linux-kernel@vger.kernel.org, Rik van Riel Subject: Re: clarification about redhat and vm In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-SAP: out X-SAP: out Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Alan Cox wrote: >>"If redhat doesn't use the -aa VM " was a short form of "if redhat >>cannot see the goodness of all the bugfixing work that happened between >>the 2.4.9 VM and any current branch 2.4, and so if they keep shipping >>2.4.9 VM as the best one for DBMS and critical VM apps like the SAP >>benchmark". >> > >The RH VM is totally unrelated to the crap in 2.4.9 vanilla. The SAP comment >begs a question. 2.4.10 seems to have problems remembering to actually >do fsync()'s. How much of your SAP benchmark is from fsync's that dont >happen ? Do you get the same values with 2.4.18-aa ? > Well, basically we checked the thing many times with quite different kernels. Our current tests - which show exactly the same results as 2.4.[10,14,15] - run on the new "official" SuSE kernel 2.4.16. Again, we observe a performance increase in high swap situations of about a factor of ten compared to 2.4.[7,9]. IMO, this shows that errors like fsync etc. are _not_ responsible for the improved performance. But of course, we will check the newer kernels as well. I think we could live with another factor of ten ... Best regards Willi ----------------------- Willi N??er SAP LinuxLab - 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/