From owner-freebsd-arch@FreeBSD.ORG Thu Mar 20 09:53:17 2008 Return-Path: Delivered-To: freebsd-arch@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id ECEF4106566B; Thu, 20 Mar 2008 09:53:17 +0000 (UTC) (envelope-from jroberson@chesapeake.net) Received: from webaccess-cl.virtdom.com (webaccess-cl.virtdom.com [216.240.101.25]) by mx1.freebsd.org (Postfix) with ESMTP id BABA88FC23; Thu, 20 Mar 2008 09:53:17 +0000 (UTC) (envelope-from jroberson@chesapeake.net) Received: from [192.168.1.107] (cpe-24-94-75-93.hawaii.res.rr.com [24.94.75.93]) (authenticated bits=0) by webaccess-cl.virtdom.com (8.13.6/8.13.6) with ESMTP id m2K9rEdv069832; Thu, 20 Mar 2008 05:53:15 -0400 (EDT) (envelope-from jroberson@chesapeake.net) Date: Wed, 19 Mar 2008 23:54:12 -1000 (HST) From: Jeff Roberson X-X-Sender: jroberson@desktop To: Robert Watson In-Reply-To: <20080320094335.R25104@fledge.watson.org> Message-ID: <20080319235358.Y910@desktop> References: <20080307020626.G920@desktop> <20080318235125.G910@desktop> <20080319172344.GX67856@elvis.mu.org> <200803191526.56761.jhb@freebsd.org> <20080319162928.V910@desktop> <20080320094335.R25104@fledge.watson.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: Daniel Eischen , arch@FreeBSD.org, Alfred Perlstein , David Xu , freebsd-arch@FreeBSD.org Subject: Re: Getting rid of the static msleep priority boost X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 20 Mar 2008 09:53:18 -0000 On Thu, 20 Mar 2008, Robert Watson wrote: > > On Wed, 19 Mar 2008, Jeff Roberson wrote: > >>> Perhaps there are no performance differences, but the cv/mutex primitives >>> are a nice clean interface that most everyone understands. If you are >>> going to write a professional OS from the ground up, I doubt you are going >>> to have anything as convoluted as msleep() as part of your kernel API/ABI. >> >> One real obstacle to converting all locations to cv_* is the lack of >> support for anything other than mtx def mutexes in the cv api. It also >> just doesn't seem like a good use of developer resources regardless of how >> you feel about msleep. > > I thought condvar was converted in 7.x to accepting a struct lock for > precisely this reason? I assume (perhaps incorrectly) that it can't be used > with spin mutexes, but thought, as a result, that we could now use it with > other lock types, such as sx locks? You are right. John did it at the same time. Good on em. > > Robert N M Watson > Computer Laboratory > University of Cambridge >