Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261319AbVDIJYP (ORCPT ); Sat, 9 Apr 2005 05:24:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261317AbVDIJYP (ORCPT ); Sat, 9 Apr 2005 05:24:15 -0400 Received: from gate.crashing.org ([63.228.1.57]:53888 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S261250AbVDIJYK (ORCPT ); Sat, 9 Apr 2005 05:24:10 -0400 Subject: Re: [patch] sched: unlocked context-switches From: Benjamin Herrenschmidt To: Ingo Molnar Cc: "Luck, Tony" , Linux Kernel list , Andrew Morton , nickpiggin@yahoo.com.au, Linux Arch list In-Reply-To: <20050409043848.GA2677@elte.hu> References: <20050409043848.GA2677@elte.hu> Content-Type: text/plain Date: Sat, 09 Apr 2005 19:22:23 +1000 Message-Id: <1113038543.9568.430.camel@gaston> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1028 Lines: 25 On Sat, 2005-04-09 at 06:38 +0200, Ingo Molnar wrote: > * Luck, Tony wrote: > > > >tested on x86, and all other arches should work as well, but if an > > >architecture has irqs-off assumptions in its switch_to() logic > > >it might break. (I havent found any but there may such assumptions.) > > > > The ia64_switch_to() code includes a section that can change a pinned > > MMU mapping (when the stack for the new process is in a different > > granule from the stack for the old process). [...] > > thanks - updated patch below. Any other architectures that switch the > kernel stack in a nonatomic way? x86/x64 switches it atomically. ppc64 already has a local_irq_save/restore in switch_to, around the low level asm bits, so it should be fine. Ben. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/