From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269688AbTGaVW3 (ORCPT ); Thu, 31 Jul 2003 17:22:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269736AbTGaVW2 (ORCPT ); Thu, 31 Jul 2003 17:22:28 -0400 Received: from holomorphy.com ([66.224.33.161]:31705 "EHLO holomorphy") by vger.kernel.org with ESMTP id S269688AbTGaVW1 (ORCPT ); Thu, 31 Jul 2003 17:22:27 -0400 Date: Thu, 31 Jul 2003 14:23:42 -0700 From: William Lee Irwin III To: "Frederick, Fabian" Cc: "Linux-Kernel (E-mail)" Subject: Re: pid_max ? Message-ID: <20030731212342.GE15452@holomorphy.com> Mail-Followup-To: William Lee Irwin III , "Frederick, Fabian" , "Linux-Kernel (E-mail)" References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 30, 2003 at 09:53:12AM +0200, Frederick, Fabian wrote: > I was looking at pid.c file and can't understand pid_max usage. > It's defined as integer (signed) =PID_MAX_DEFAULT (which is 0x8000 (on old > arch, integer max positive value isn't 32767 ? so 0x8000 -> -32768). > In alloc_pidmap, 'if (pid>=pid_max)' should be in that case always > true so pid=RESERVED_PIDS which is 300 (?).Why not use pid>PID_MAX_DEFAULT > there and forget the pid_max definition ? and why do we have that '300' > value ? It's to avoid trying to allocate from the range of pid's typically used by kernel threads and system daemons after bootup. There are no hard dependencies on it, it's merely "traditional pidspace layout". -- wli