From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754158AbbKXJwI (ORCPT ); Tue, 24 Nov 2015 04:52:08 -0500 Received: from casper.infradead.org ([85.118.1.10]:47928 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753343AbbKXJwD (ORCPT ); Tue, 24 Nov 2015 04:52:03 -0500 Date: Tue, 24 Nov 2015 10:51:56 +0100 From: Peter Zijlstra To: Tejun Heo Cc: Oleg Nesterov , Ingo Molnar , Rik van Riel , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/1] stop_machine: Remove stop_cpus_lock and lg_double_lock/unlock() Message-ID: <20151124095156.GP17308@twins.programming.kicks-ass.net> References: <20151121181129.GA425@redhat.com> <20151121181148.GA433@redhat.com> <20151123215339.GF19072@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151123215339.GF19072@mtj.duckdns.org> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 23, 2015 at 04:53:39PM -0500, Tejun Heo wrote: > > Isn't this a lot more subtler than the other direction? Unless > there's a clear performance advantage to removing stopper->lock, using > lglock for both stop_two and stop_machine seems like an > easier-to-follow approach to me. The idea is to kill lglock. There's only two users, this and fs/locks.c for which I have patches -- which are being benchmarked 'now-ish' :-)