From owner-freebsd-hackers Fri Aug 3 11: 3:29 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from elvis.mu.org (elvis.mu.org [216.33.66.196]) by hub.freebsd.org (Postfix) with ESMTP id 1116E37B403 for ; Fri, 3 Aug 2001 11:03:26 -0700 (PDT) (envelope-from bright@elvis.mu.org) Received: by elvis.mu.org (Postfix, from userid 1192) id 176C381D0A; Fri, 3 Aug 2001 13:03:26 -0500 (CDT) Date: Fri, 3 Aug 2001 13:03:26 -0500 From: Alfred Perlstein To: "Eugene L. Vorokov" Cc: freebsd-hackers@freebsd.org Subject: Re: device i/o question Message-ID: <20010803130326.C85642@elvis.mu.org> References: <200108030949.f739nrZ03446@bugz.infotecs.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200108030949.f739nrZ03446@bugz.infotecs.ru>; from vel@bugz.infotecs.ru on Fri, Aug 03, 2001 at 01:49:53PM +0400 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Eugene L. Vorokov [010803 04:33] wrote: > Hello, > > I have a module which creates new device for data exchange between user > program and a module. I was wondering, if I open the device in userspace > and write() some piece of data to it, is it guaranteed that the driver > will get this solid piece of data at once, or in certain circumstances > it can be split into parts which are passed to the driver as several > write events ? I'm pretty sure a single user call of write(2) should translate into a single write to your device. There are limits on the size one can write(2) thought. -- -Alfred Perlstein [alfred@freebsd.org] Ok, who wrote this damn function called '??'? And why do my programs keep crashing in it? To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message