From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753893AbdCXIGP (ORCPT ); Fri, 24 Mar 2017 04:06:15 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:56380 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751295AbdCXIGA (ORCPT ); Fri, 24 Mar 2017 04:06:00 -0400 Date: Fri, 24 Mar 2017 09:05:39 +0100 From: Peter Zijlstra To: Stephen Rothwell Cc: Andrew Morton , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: linux-next: manual merge of the akpm tree with the tip tree Message-ID: <20170324080539.2bmioalq5hmcsz6f@hirez.programming.kicks-ass.net> References: <20170324164026.4f305846@canb.auug.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170324164026.4f305846@canb.auug.org.au> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 24, 2017 at 04:40:26PM +1100, Stephen Rothwell wrote: > Hi all, > > Today's linux-next merge of the akpm tree got a conflict in: > > arch/x86/include/asm/atomic.h > > between commit: > > e6790e4b5d5e ("locking/atomic/x86: Use atomic_try_cmpxchg()") > > from the tip tree and patch: > > "x86/atomic: move __arch_atomic_add_unless out of line" > > from the akpm tree. Urgh, that patch shouldn't be in mm in any case. Also with the try_cmpxchg() change, the text gain is reduced (about half). Furthermore, micro-benchmarks show that turning cmpxchg loops like this into a function makes them more expensive; see: https://lkml.kernel.org/r/20170322165144.dtidvvbxey7w5pbd@hirez.programming.kicks-ass.net