From owner-freebsd-hackers Sun Oct 29 20:09:41 1995 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id UAA29493 for hackers-outgoing; Sun, 29 Oct 1995 20:09:41 -0800 Received: from rah.star-gate.com (rah.star-gate.com [204.188.121.18]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id UAA29478 for ; Sun, 29 Oct 1995 20:09:37 -0800 Received: from rah.star-gate.com (localhost.v-site.net [127.0.0.1]) by rah.star-gate.com (8.6.12/8.6.9) with ESMTP id UAA10427 for ; Sun, 29 Oct 1995 20:09:23 -0800 Message-Id: <199510300409.UAA10427@rah.star-gate.com> X-Mailer: exmh version 1.6.2 7/18/95 To: hackers@FreeBSD.ORG Subject: Buffer cache , lmbench part 3 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sun, 29 Oct 1995 20:09:22 -0800 From: "Amancio Hasty Jr." Sender: owner-hackers@FreeBSD.ORG Precedence: bulk Jim Lowe recorded the last space shuttle launch on his FreeBSD box;however, he ran into a minor gotcha the buffer cache. If you want to see the buffer cache in action just play the mpeg movie and look for pauses on on the movie. So the question now is: Is the buffer cache tuneble to avoid this kind of behavior? I was thinking that video capture without compression eats up enourmous amount of disk space so it would not be too unconceivable to bypass the file system and buffer cache and just do raw I/O to the disk. Here is a pointer to Jim's mpeg version of the space shuttle launch it is about 1.7mb and the original was 300MB : ftp://ftp.cs.uwm.edu/pub/shuttle_gifs/sts73.launch.mpg. Enjoy, Amancio