From owner-cvs-src@FreeBSD.ORG Tue Jan 1 09:46:53 2008 Return-Path: Delivered-To: cvs-src@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3134916A41B; Tue, 1 Jan 2008 09:46:53 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85]) by mx1.freebsd.org (Postfix) with ESMTP id CAF5013C4E7; Tue, 1 Jan 2008 09:46:52 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.14.1/8.14.1) with ESMTP id m019jjFp023236; Tue, 1 Jan 2008 02:45:45 -0700 (MST) (envelope-from imp@bsdimp.com) Date: Tue, 01 Jan 2008 02:45:46 -0700 (MST) Message-Id: <20080101.024546.1079618522.imp@bsdimp.com> To: brde@optusnet.com.au From: "M. Warner Losh" In-Reply-To: <20080101161858.A10345@delplex.bde.org> References: <200712311219.08286.jhb@freebsd.org> <20071231.203720.1306324107.imp@bsdimp.com> <20080101161858.A10345@delplex.bde.org> X-Mailer: Mew version 5.2 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: rrs@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org, jhb@FreeBSD.org, cvs-src@FreeBSD.org Subject: Re: cvs commit: src/sys/netinet sctp_bsd_addr.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Jan 2008 09:46:53 -0000 In message: <20080101161858.A10345@delplex.bde.org> Bruce Evans writes: : On Mon, 31 Dec 2007, M. Warner Losh wrote: : : > In message: <200712311219.08286.jhb@freebsd.org> : > John Baldwin writes: : : > : The more correct fix though is to do a 'sched_prio()' at the start of the : > : thread's main loop to set the priority and then not adjust it via msleep(). : > : Kernel threads really should never pass a priority to msleep() but always '0' : > : (which means "don't change my priority"). : > : > Not PZERO? When should one use PZERO and when should one use a bare : > '0'? Can this information be added to the man page? : : PZERO is compatibility cruft which should never be used. Just a few : places in kern still use it to invent a priority when no suitable : priority (like PSOCK or PRIBIO) is already #defined. It isn't clear : where these invented priorities are suitable. Do we want to document the other Pxxxx priorities? : Otherwise, PZERO has a completely different meaning from either priority : 0 (maximal) or the bare 0 arg to msleep. It means some middle priority, : or the bias from priority 0 to get to that middle priority, so that : after subtracting it, 0 becomes the middle priority. The bare 0 is : actualy priority 0 (maximal) overloaded to mean "don't change the : priority". This overloading doesn't lose anything except clarity since : nothing is permitted to wake up at maximal priority after a sleep. : (Maximal priority is reserved for realtime priority ithreads and even : much lower priority ithreads are not permitted to sleep, and non-interrupt : threads aren't permitted to run at ithread priorities except temporarily : for priority propagation.) So would the following be a reasonable change to sleep.9? Index: sleep.9 =================================================================== RCS file: /home/ncvs/src/share/man/man9/sleep.9,v retrieving revision 1.61 diff -u -r1.61 sleep.9 --- sleep.9 30 Mar 2007 18:07:26 -0000 1.61 +++ sleep.9 1 Jan 2008 09:44:01 -0000 @@ -93,6 +93,10 @@ runnable with the specified .Fa priority when it resumes. +.Dv PZERO +should never be used, as it is for compatibility only. +A new priority of 0 means to use the thread's current priority when +it is made runnable again. If .Fa priority includes the Warner