Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761471AbYGOCVW (ORCPT ); Mon, 14 Jul 2008 22:21:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752990AbYGOCVO (ORCPT ); Mon, 14 Jul 2008 22:21:14 -0400 Received: from yw-out-2324.google.com ([74.125.46.30]:23745 "EHLO yw-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752178AbYGOCVN (ORCPT ); Mon, 14 Jul 2008 22:21:13 -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=NQU1NsAUnNpRyZLaW+xuaLaZlGv2IB2ekQHax6HexhfI2CEpwbbiXoxpi0Z0seUDnE 5fBiW54HJ30nijmSTcgVtbfjJyXC6vvPECdBC+3rUEhQL6h+Ky9AqKSh6YH2TeQojSNC Al7NsT+z5nSt78GzLaC4ycLxY2ko4VZXzyZmI= Message-ID: Date: Tue, 15 Jul 2008 04:21:10 +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> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1361 Lines: 41 2008/7/15 Linus Torvalds : > > > On Tue, 15 Jul 2008, Dmitry Adamushko wrote: >> >> The 'synchronization' point occurs even earlier - when cpu_down() -> >> __stop_machine_run() gets called (as I described in my previous mail). >> >> My point was that if it's ok to have a _delayed_ synchronization >> point, having it not immediately after cpu_clear(cpu, cpu_active_map) >> but when the "runqueue lock" is taken a bit later (as you pointed out >> above) or __stop_machine_run() gets executed (which is a sync point, >> scheduling-wise), >> >> then we can implement the proper synchronization (hotplugging vs. >> task-migration) with cpu_online_map (no need for cpu_active_map). > > [ ... ] > > In particular, it should tell you that the code is too hard to follow, and > too fragile, and a total mess. > > I do NOT understand why you seem to argue for being "subtle" and "clever", > considering the history of this whole setup. Subtle and clever and complex > is what got us to the crap situation. Fair enough, agreed. > > 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/