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 16:58:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 2 Apr 2003 16:58:59 -0500 Received: from svr-ganmtc-appserv-mgmt.ncf.coxexpress.com ([24.136.46.5]:33028 "EHLO svr-ganmtc-appserv-mgmt.ncf.coxexpress.com") by vger.kernel.org with ESMTP id ; Wed, 2 Apr 2003 16:58:58 -0500 Subject: Re: fairsched + O(1) process scheduler From: Robert Love To: Antonio Vargas Cc: William Lee Irwin III , linux-kernel@vger.kernel.org In-Reply-To: <20030402220734.GC13168@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> Content-Type: text/plain Organization: Message-Id: <1049321427.2872.25.camel@localhost> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.3 (1.2.3-1) Date: 02 Apr 2003 17:10:27 -0500 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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. > 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. Robert Love