From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from max.phys.uu.nl (max.phys.uu.nl [131.211.32.73]) by kvack.org (8.8.7/8.8.7) with ESMTP id MAA26731 for ; Thu, 25 Jun 1998 12:05:14 -0400 Received: from mirkwood.dummy.home (root@anx1p7.phys.uu.nl [131.211.33.96]) by max.phys.uu.nl (8.8.7/8.8.7/hjm) with ESMTP id SAA04397 for ; Thu, 25 Jun 1998 18:05:07 +0200 (MET DST) Received: from localhost (riel@localhost) by mirkwood.dummy.home (8.9.0/8.8.3) with SMTP id SAA32603 for ; Thu, 25 Jun 1998 18:00:15 +0200 Date: Thu, 25 Jun 1998 18:00:15 +0200 (CEST) From: Rik van Riel Reply-To: Rik van Riel Subject: Memory management. (fwd) Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org To: Linux MM List-ID: Hi, I found this message in my INBOX today. It might be interesting to read... (I know that Eric and Stephen are working on eliminating said problem) Rik. ---------- Forwarded message ---------- Date: Thu, 25 Jun 1998 16:22:11 +0200 From: Stefane Fermigier To: H.H.vanRiel@phys.uu.nl Subject: Memory management. Hi, thanks for submiting your page to Linux Center. I have a question for the MM team: yesterday, there was a seminar on free software at the Pari 8 university, and someone called Louis Leon, well known as a benchmarker of workstations performances for the french magazine ``LMB'' asked the following rather technical question. He said that under most circumstances, Linux was able to get the best results, but that when huge amounts of data were to be transfered from and then to disk during the computations, performances were dropping badly. This would appear when the size of the files that are manipulated is _half_ of the RAM of the systems, when one would think that RAM just (approximately) _equal_ to the size of the files would be enough. According to Remy Card, this might be a question of ``double buffering'', that is, the data would go to _two_ different RAM buffers instead of just one. A guy from the FreeBSD, who was speaking at the conference, was happy to say that this doesn't happen under FreeBSD. What do you think of this? Is it something that you are aware of? Are you working on that kind of problems? Regards, S. -- Stefane Fermigier, MdC a l'Universite Paris 7. Tel: 01.44.27.61.01 (Bureau). , , . "A complex system that works is invariably found to have evolved from a simple system that worked." Grady Booch.