From owner-freebsd-hackers Thu Apr 17 20:21:40 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id UAA28451 for hackers-outgoing; Thu, 17 Apr 1997 20:21:40 -0700 (PDT) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id UAA28445 for ; Thu, 17 Apr 1997 20:21:36 -0700 (PDT) Received: (from msmith@localhost) by genesis.atrad.adelaide.edu.au (8.8.5/8.7.3) id MAA21156; Fri, 18 Apr 1997 12:49:58 +0930 (CST) From: Michael Smith Message-Id: <199704180319.MAA21156@genesis.atrad.adelaide.edu.au> Subject: Re: video capture driver interface to file system? In-Reply-To: <199704180304.UAA01268@rah.star-gate.com> from Amancio Hasty at "Apr 17, 97 08:04:28 pm" To: hasty@rah.star-gate.com (Amancio Hasty) Date: Fri, 18 Apr 1997 12:49:58 +0930 (CST) Cc: msmith@atrad.adelaide.edu.au, terry@lambert.org, freebsd-hackers@freebsd.org X-Mailer: ELM [version 2.4ME+ PL28 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Amancio Hasty stands accused of saying: > > Not interested in using write nor any user level api. Ok, so you want the kernel to do the work for you. Have a look at kern/kern_ktrace..c for how ktrace does it; it gets an fd passed in from userland (which is the right place for manipulating files etc.), and writes to it. It also demonstrates using multiple iov entries for writing multiple non-contiguous buffers. > For the purpose of this discussion, what I want to do is when I get a frame > in a buffer to pass a token to a file system routine to write the buffer > to disk. The object is to avoid unnecessarily copying the buffer. If you don't want to futz around with filesystems, then you need to play with bwrite, and you will want to talk to John D. about that. > Amancio -- ]] Mike Smith, Software Engineer msmith@gsoft.com.au [[ ]] Genesis Software genesis@gsoft.com.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control. (ph) +61-8-8267-3493 [[ ]] Unix hardware collector. "Where are your PEZ?" The Tick [[