From owner-svn-src-head@FreeBSD.ORG Mon Nov 3 11:18:57 2014 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 4416E80D; Mon, 3 Nov 2014 11:18:57 +0000 (UTC) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id BC14FF69; Mon, 3 Nov 2014 11:18:56 +0000 (UTC) Received: from tom.home (kostik@localhost [127.0.0.1]) by kib.kiev.ua (8.14.9/8.14.9) with ESMTP id sA3BIpBd027189 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 3 Nov 2014 13:18:51 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.9.2 kib.kiev.ua sA3BIpBd027189 Received: (from kostik@localhost) by tom.home (8.14.9/8.14.9/Submit) id sA3BIpk1027188; Mon, 3 Nov 2014 13:18:51 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Mon, 3 Nov 2014 13:18:51 +0200 From: Konstantin Belousov To: Attilio Rao Subject: Re: svn commit: r273966 - in head: share/man/man9 sys/kern sys/sys Message-ID: <20141103111851.GM53947@kib.kiev.ua> References: <20141102165916.GY53947@kib.kiev.ua> <20141102174958.GZ53947@kib.kiev.ua> <20141102191029.GA53947@kib.kiev.ua> <20141102213819.GF53947@kib.kiev.ua> <20141102224934.GG53947@kib.kiev.ua> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.0 X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on tom.home Cc: "svn-src-head@freebsd.org" , "svn-src-all@freebsd.org" , "src-committers@freebsd.org" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Nov 2014 11:18:57 -0000 On Mon, Nov 03, 2014 at 11:34:48AM +0100, Attilio Rao wrote: > On Sun, Nov 2, 2014 at 11:49 PM, Konstantin Belousov > wrote: > > On Sun, Nov 02, 2014 at 11:37:57PM +0100, Attilio Rao wrote: > >> On Sun, Nov 2, 2014 at 10:38 PM, Konstantin Belousov > >> wrote: > >> > On Sun, Nov 02, 2014 at 10:17:26PM +0100, Attilio Rao wrote: > >> >> I think that your initial patch (what is in head now) is a better approach. > >> >> I would just make it a lockinit() flag to make it less alien to the KPI. > >> >> > >> > > >> > Ok. > >> > > >> > Can you explain what would the proposed lockinit() flag do ? What should > >> > it change comparing with the current code ? > >> > >> You now provide LK_NODDLKTREAT on a call basis. > >> The lockinit() flag would embed this into the lock attribute and make > >> it always real, without the need for the callers to provide > >> LK_NODDLKTREAT on a call basis. > > > > Am I reading your proposal right ? Do you mean, that for all vnodes, > > I should disable exclusive starvation avoidance at all ? I completely > > disagree with this. > > No, I'm saying that we should support doing this at the KPI level. Not > that you should enable this for all the vnodes. I am unable to decipher your proposal. The property of guaranteed non-recursive shared request is per call site, it is not global for the life of lock. As such, I do not understand what would a proposed flag for lockinit(9) indicate to kern_lock.c, vs. the currently passed flag to __lockmgr_args(9). Only specific calls need to avoid check for td_lk_slocks != 0, not specific locks.