From owner-freebsd-hackers Thu Nov 1 10: 0:29 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from srv1.cosmo-project.de (srv1.cosmo-project.de [213.83.6.106]) by hub.freebsd.org (Postfix) with ESMTP id 166BC37B406 for ; Thu, 1 Nov 2001 10:00:23 -0800 (PST) Received: (from uucp@localhost) by srv1.cosmo-project.de (8.11.0/8.11.0) with UUCP id fA1I0HL96382; Thu, 1 Nov 2001 19:00:17 +0100 (CET) Received: from mail.cicely.de (cicely20.cicely.de [10.1.1.22]) by cicely5.cicely.de (8.12.1/8.12.1) with ESMTP id fA1HrGqb016280; Thu, 1 Nov 2001 18:53:17 +0100 (CET)?g (envelope-from ticso@cicely8.cicely.de) Received: from cicely8.cicely.de (cicely8.cicely.de [10.1.2.10]) by mail.cicely.de (8.11.0/8.11.0) with ESMTP id fA1HrGF20274; Thu, 1 Nov 2001 18:53:16 +0100 (CET) Received: (from ticso@localhost) by cicely8.cicely.de (8.11.4/8.11.4) id fA1Hr4r09763; Thu, 1 Nov 2001 18:53:04 +0100 (CET) (envelope-from ticso) Date: Thu, 1 Nov 2001 18:53:02 +0100 From: Bernd Walter To: lg@deny.ru Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: Unix Philosophers Please! Message-ID: <20011101185302.A9563@cicely8.cicely.de> References: <20011101161748.E7563@cicely8.cicely.de> <200111012029.fA1KTdZ70776@lg.deny.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200111012029.fA1KTdZ70776@lg.deny.ru> User-Agent: Mutt/1.3.23i X-Operating-System: FreeBSD cicely8.cicely.de 5.0-CURRENT i386 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 On Thu, Nov 01, 2001 at 08:29:39PM +0000, lg wrote: > > In short: The data is tranfered into the kernel and dropped there. > my source /usr/src/sys/i386/i386/mem.c [FreeBSD-4.3-RELEASE] > says that data doesnt transfered into kernel. I was looking into -current. Null and *random have been seprarated in -current. > kernel just do: (when you write to device with major 2, minor 2) > .... > c = iov->iov_len; > .... > iov->iov_base += c; > iov->iov_len -= c; > uio->uio_offset += c; > uio->uio_resid -= c; > .... > [ where iov is uio->uio_iov ] > > so data doesnt go anywhere. Sorry - you are right. No data is copied into the kernel as it would be the job of null_write() to do if needed. -- B.Walter COSMO-Project http://www.cosmo-project.de ticso@cicely.de Usergroup info@cosmo-project.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message