Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967699AbXEHDIJ (ORCPT ); Mon, 7 May 2007 23:08:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S967645AbXEHDIE (ORCPT ); Mon, 7 May 2007 23:08:04 -0400 Received: from ozlabs.org ([203.10.76.45]:42940 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967631AbXEHDIB (ORCPT ); Mon, 7 May 2007 23:08:01 -0400 Subject: Re: [BUG] cpu-hotplug: Can't offline the CPU with naughty realtime processes From: Rusty Russell To: Satoru Takeuchi Cc: Linux Kernel , Srivatsa Vaddagiri , Zwane Mwaikambo , Nathan Lynch , Joel Schopp , Ashok Raj , Heiko Carstens , Gautham R Shenoy In-Reply-To: <877irkrq8a.wl%takeuchi_satoru@jp.fujitsu.com> References: <87bqgxrlky.wl%takeuchi_satoru@jp.fujitsu.com> <1178545373.28438.7.camel@localhost.localdomain> <877irkrq8a.wl%takeuchi_satoru@jp.fujitsu.com> Content-Type: text/plain Date: Tue, 08 May 2007 13:02:25 +1000 Message-Id: <1178593345.28438.29.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1045 Lines: 29 On Tue, 2007-05-08 at 11:41 +0900, Satoru Takeuchi wrote: > At Mon, 07 May 2007 23:42:53 +1000, > Rusty Russell wrote: > > I look forward to your patch! > > Rusty. > > Thanks, I'll do. Maybe this work will take several days including test. Excellent. > BTW, how should I manage rt process having max priority as Gautham said? > He said that it's OK unless such kernel thread exists. However, currently > MAX_USER_RT_PRIORITY is equal to MAX_RT_PRIO, so user process also be able > to cause this problem. Is Srivatsa's idea 2 acceptable? Or just apply > "Shouldn't abuse highest rt proority" rule? We used to be able to create kernel threads higher than any userspace priority. If this is no longer true, I think that's OK: equal priority still means we'll get scheduled, right? Cheers, Rusty. - 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/