Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756092AbYGLXTT (ORCPT ); Sat, 12 Jul 2008 19:19:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753458AbYGLXTL (ORCPT ); Sat, 12 Jul 2008 19:19:11 -0400 Received: from rv-out-0506.google.com ([209.85.198.234]:1292 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752387AbYGLXTK (ORCPT ); Sat, 12 Jul 2008 19:19:10 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=Q703iSGWvUyM2H0m67o0eKZ3FaS9dA3dEuJPqJ5A1onsEVMKPnp0JQxZ+tbvM1oyNf ug8kGcob51QRreKatz0As6fjeRAhwizipKyaq0/fkUvBFeMsoGPagpvMMOai9QH5LEP0 g64KdbELh1Ztv+Nt0I9KL+X2L6m1bFrsPuU+s= Message-ID: Date: Sun, 13 Jul 2008 01:19:09 +0200 From: "Dmitry Adamushko" To: "Linus Torvalds" Subject: Re: current linux-2.6.git: cpusets completely broken Cc: "Vegard Nossum" , "Paul Menage" , "Max Krasnyansky" , "Paul Jackson" , "Peter Zijlstra" , miaox@cn.fujitsu.com, rostedt@goodmis.org, "Thomas Gleixner" , "Ingo Molnar" , "Linux Kernel" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080712031736.GA3040@damson.getinternet.no> <19f34abd0807121600l653e28bfwb5cce2d880b7f2cd@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1619 Lines: 46 2008/7/13 Linus Torvalds : > >> (A little pet horse for the occasion: Testing can show the presence of >> errors, but not their absence. But that's a different story.) > > Absolutely. Which is actually why I prefer my patch. I think it fixes - in > general - the issue of CPU migration migrating tasks back to the CPU that > we're taking down. > > The other patches seem to work around just the problem that _triggers_ the > bug. They don't actually make it impossible to migrate to a CPU that is > getting shut down - they just try to avoid the particular sequence that > made it happen for you. Well, they try to make sched-domains consistent for all possible cases, not just any particular case. So no, they don't allow a possibility to leave tasks on a dead CPU (unless there is another bug). With your patch (and a cpusets :: hotplug handler from the current -git) sched-domains are still broken and they are used in a number of places. So why keep them at all? I'm really surprised that Vegard says this "cpu_active_map" patch alone fixes the problem. With your modifications of common_cpu_mem_hotplug_unplug() - yes but then it will work even without "cpu_active_map". (ok, unless I'm really blind at this late hour so please direct me to the right way :-) > > Linus > -- Best regards, Dmitry Adamushko -- 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/