From owner-freebsd-hackers Mon Aug 28 14:27:27 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.FreeBSD.org (8.6.11/8.6.6) id OAA27543 for hackers-outgoing; Mon, 28 Aug 1995 14:27:27 -0700 Received: from mpp.minn.net (mpp.Minn.Net [204.157.201.242]) by freefall.FreeBSD.org (8.6.11/8.6.6) with ESMTP id OAA27536 for ; Mon, 28 Aug 1995 14:27:24 -0700 Received: (from mpp@localhost) by mpp.minn.net (8.6.11/8.6.9) id QAA27212; Mon, 28 Aug 1995 16:31:17 -0500 From: Mike Pritchard Message-Id: <199508282131.QAA27212@mpp.minn.net> Subject: Re: 16-bit pids? (was Re: 16, 32, and 64bit types?) To: frank@exit.com (Frank Mayhar) Date: Mon, 28 Aug 1995 16:31:17 -0500 (CDT) Cc: hackers@freefall.FreeBSD.org In-Reply-To: <199508282036.NAA04576@exit.com> from "Frank Mayhar" at Aug 28, 95 01:36:26 pm X-Mailer: ELM [version 2.4 PL24 ME7a] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1238 Sender: hackers-owner@FreeBSD.org Precedence: bulk Frank Mayhar wrote: > > Just an aside, not directly related to the original subject. > > > Type FreeBSD NetBSDr1994/12) Right > > ---- ------- --------------- ----- > > min_pid_t - - u16_t (for PID_MAX = 30000) > > kernel_pid_t - - kernel_promote(min_pid_t) > > pid_t long int32_t user_promote(min_pid_t) > > Sixteen bits for PID_MAX? Yukko! IMHO, this should be at least 32, and > preferably a black-box type (handled by allocate_pid(), not by an int > increment, as fast that that might be -- it's still one of the least > critical bits of fork()). Some distributed systems need at least 32 > bits for the pid, since they add node information, and a black-box type > would make this much easier. > > Granted, it's a nontrivial change, but it would be nice to see some system > do it right. I don't think there's any inherent reason why pid_t should > be limited to an int (of any size) in modern Un*ces. Since the subject of PID_MAX has come up, what is the reason for having it set to 30,000? That isn't really that large of a value, especially on a busy system. How about raising it to something like 90,000? -- Mike Pritchard mpp@mpp.minn.net "Go that way. Really fast. If something gets in your way, turn"