From owner-freebsd-current Mon Dec 1 14:02:42 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id OAA24270 for current-outgoing; Mon, 1 Dec 1997 14:02:42 -0800 (PST) (envelope-from owner-freebsd-current) Received: from dyson.iquest.net (dyson.iquest.net [198.70.144.127]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id OAA24253 for ; Mon, 1 Dec 1997 14:02:27 -0800 (PST) (envelope-from toor@dyson.iquest.net) Received: (from root@localhost) by dyson.iquest.net (8.8.7/8.8.8) id RAA07400; Mon, 1 Dec 1997 17:02:21 -0500 (EST) (envelope-from toor) From: "John S. Dyson" Message-Id: <199712012202.RAA07400@dyson.iquest.net> Subject: Re: FYI: usage of new AIO calls In-Reply-To: <199712012154.OAA12784@mt.sri.com> from Nate Williams at "Dec 1, 97 02:54:44 pm" To: nate@mt.sri.com (Nate Williams) Date: Mon, 1 Dec 1997 17:02:21 -0500 (EST) Cc: toor@dyson.iquest.net, nate@mt.sri.com, current@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL31 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-current@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Nate Williams said: > I wrote: > > What is a VCHR device? > > John replied: > > > VCHR files are character devices that you would see the 'c' in the > > first column for 'ls -l'. > > Ahh, character special devices. SEF also pointed this out to me right > after I got this email. I know what those are, but I've never heard > them distinguished as VCHR devices. > > I'm all better now, must have been too much Turkey. *grin* > > > If you know what the AIO/LIO functions are for, and have software that > > One more question. AIO == Asynchronous I/O, but LIO? > AIO == Asynchronous I/O. LIO == List (directed) I/O. LIO essentially allows for multiple AIO requests to be batched into a single system call. It is kind of like writev/readv, except you can intermix read and write system calls with LIO. With LIO, you can specify a signal to post when it is fully done. signanosleep(2) is especially useful in conjunction with LIO. -- John dyson@freebsd.org jdyson@nc.com