From owner-freebsd-hackers@FreeBSD.ORG Wed Dec 15 15:12:11 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D353216A4CE for ; Wed, 15 Dec 2004 15:12:11 +0000 (GMT) Received: from comsys.ntu-kpi.kiev.ua (comsys.ntu-kpi.kiev.ua [194.125.244.127]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7802A43D4C for ; Wed, 15 Dec 2004 15:11:48 +0000 (GMT) (envelope-from simon@comsys.ntu-kpi.kiev.ua) Received: from pm514-9.comsys.ntu-kpi.kiev.ua (pm514-9.comsys.ntu-kpi.kiev.ua [10.18.54.109]) (authenticated bits=0)iBFFCTjT034077 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 15 Dec 2004 17:12:34 +0200 (EET) Received: by pm514-9.comsys.ntu-kpi.kiev.ua (Postfix, from userid 1000) id E4FAA37F; Wed, 15 Dec 2004 17:10:29 +0200 (EET) Date: Wed, 15 Dec 2004 17:10:29 +0200 From: Andrey Simonenko To: Ravi Krishna Message-ID: <20041215151029.GA2832@pm514-9.comsys.ntu-kpi.kiev.ua> References: <6669fd8604121506494c5afe65@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6669fd8604121506494c5afe65@mail.gmail.com> User-Agent: Mutt/1.4.2.1i X-Spam-Status: No, score=-4.5 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.0.1 X-Spam-Checker-Version: SpamAssassin 3.0.1 (2004-10-22) on comsys.ntu-kpi.kiev.ua cc: freebsd-hackers@freebsd.org Subject: Re: FreeBSD system call implementation X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 15 Dec 2004 15:12:11 -0000 On Wed, Dec 15, 2004 at 08:19:05PM +0530, Ravi Krishna wrote: > My question is why we store the p->p_sysent->sv_table > for each process. What is the reason for keeping this per process? > Are there some situations where two processes can have different system calls > available? Processes can have different p_sysent, because the kernel supports different ABIs. sv_entry (pointer to some system call table) is only one part, read comments in sys/sysent.h file for sysentvec structure.