From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 2 Apr 2003 17:16:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 2 Apr 2003 17:16:56 -0500 Received: from 217-125-129-224.uc.nombres.ttd.es ([217.125.129.224]:21232 "HELO cocodriloo.com") by vger.kernel.org with SMTP id ; Wed, 2 Apr 2003 17:16:55 -0500 Date: Thu, 3 Apr 2003 00:35:57 +0200 From: Antonio Vargas To: Robert Love Cc: Antonio Vargas , William Lee Irwin III , linux-kernel@vger.kernel.org Subject: Re: fairsched + O(1) process scheduler Message-ID: <20030402223557.GD13168@wind.cocodriloo.com> References: <20030401125159.GA8005@wind.cocodriloo.com> <20030401164126.GA993@holomorphy.com> <20030401221927.GA8904@wind.cocodriloo.com> <20030402124643.GA13168@wind.cocodriloo.com> <20030402163512.GC993@holomorphy.com> <20030402213629.GB13168@wind.cocodriloo.com> <1049319300.2872.21.camel@localhost> <20030402220734.GC13168@wind.cocodriloo.com> <1049321427.2872.25.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1049321427.2872.25.camel@localhost> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 02, 2003 at 05:10:27PM -0500, Robert Love wrote: > On Wed, 2003-04-02 at 17:07, Antonio Vargas wrote: > > > Hmmm, we had some way for executing code just after an interrupt, > > but outside interrupt scope... was it a bottom half? Can you > > point me to some place where it's done? > > Unfortunately uidhash_lock cannot be used from a bottom half either. > > You can push it into a work queue. See schedule_work() and the default > events queue. I'll take a look. > > Ok, I did know m68k can do it, but wasn't sure about all other arches :) > > Yep. Everyone architecture I know of - and certainly all that Linux > support - can do atomic read/writes to a word. Thinking about it, it > would be odd if not (two writes to a single word interleaving?). There > are places this assumption is used. > > Anything more complicated, of course, needs atomic operations or locks. "word == basic unit of transfer from/to memory" on your reasoning, I suppose. I'm coding this now, hope I can post a basic implementation. Greets, Antonio.