From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964972AbWD0ISq (ORCPT ); Thu, 27 Apr 2006 04:18:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964975AbWD0ISq (ORCPT ); Thu, 27 Apr 2006 04:18:46 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:11706 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S964972AbWD0ISp (ORCPT ); Thu, 27 Apr 2006 04:18:45 -0400 Date: Thu, 27 Apr 2006 10:23:57 +0200 From: Ingo Molnar To: Simon Derr Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] 2.6.16-rt17 on IA64 Message-ID: <20060427082357.GA1874@elte.hu> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: -2.8 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.8 required=5.9 tests=ALL_TRUSTED,AWL autolearn=no SpamAssassin version=3.0.3 -2.8 ALL_TRUSTED Did not pass through any untrusted hosts 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Simon Derr wrote: > Hi, > > This is a first version of my port of Ingo's -rt kernel to the IA64 > arch. nice! I've added this to the -rt tree and have released -rt18. > So far the kernel boots with PREEMPT_RT enabled (on a 4-cpu tiger), > and that's about it. I've not done extensive tests (only > scripts/rt-tester), nor any measurements of any kind. > > There's very probably many bugs I'm not aware of. > > But there is already one thing I know should be fixed : I've changed > the declaration of (struct zone).lock (in include/linux/mmzone.h) from > spinlock_t to raw_spinlock_t. > > I did this because on IA64, cpu_idle(), which is not allowed to call > schedule(), calls check_pgt_cache(). I guess this could be fixed by > moving this call to another kernel thread... ideas are welcome. this should definitely be cleaned up. There are a couple of periodic VM threads you could do this from - but none is really per-CPU. So my suggestion would be to do the check_pgt_cache() from desched_thread() - which is an rt-specific cleanup thread. You dont even have to make it ia64-specific i think. Ingo