Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965890AbbDVJUq (ORCPT ); Wed, 22 Apr 2015 05:20:46 -0400 Received: from ud10.udmedia.de ([194.117.254.50]:49171 "EHLO mail.ud10.udmedia.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965712AbbDVJUo (ORCPT ); Wed, 22 Apr 2015 05:20:44 -0400 Date: Wed, 22 Apr 2015 11:20:41 +0200 From: Markus Trippelsdorf To: Hagen Paul Pfeifer Cc: Ingo Molnar , Linus Torvalds , Borislav Petkov , "linux-kernel@vger.kernel.org" , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Peter Zijlstra , Andrew Morton Subject: Re: [PATCH RFC] x86: enforce inlining for atomics Message-ID: <20150422092040.GB395@x4> References: <1429565231-4609-1-git-send-email-hagen@jauu.net> <20150420215645.GC10191@pd.tnic> <20150421074212.GA25081@gmail.com> <20150421225723.GA5927@virgo.local> <20150422052441.GA395@x4> <20150422055848.GA3307@virgo.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150422055848.GA3307@virgo.local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1451 Lines: 41 On 2015.04.22 at 07:58 +0200, Hagen Paul Pfeifer wrote: > * Markus Trippelsdorf | 2015-04-22 07:24:41 [+0200]: > >I cannot reproduce this issue with my config with 4.8, 4.9 or 5. Could > >you please come up with a small testcase and open a gcc bug (with full > >gcc command line)? > > the attached config file should do the trick. Can you try it? It is definitely a -O2 vs. -Os issue. With your config: -Os: % nm vmlinux | grep " atomic_" | wc -l 736 -O2 is fine: % nm vmlinux | grep " atomic_" ffffffff852d8300 r atomic_counters_ops ffffffff83d66bf0 t atomic_counters_read ffffffff8119cd30 T atomic_dec_and_mutex_lock ffffffff81172e10 T atomic_notifier_call_chain ffffffff81172b90 T atomic_notifier_chain_register ffffffff81172d70 T atomic_notifier_chain_unregister ffffffff844b0ef0 t atomic_read_file ffffffff85a0c260 r atomic_ro_fops ffffffff87616000 d atomic_rw ffffffff852d8400 r atomic_stats_ops ffffffff83d66c50 t atomic_stats_read The easiest fix would be to force always-inline in include/linux/compiler-gcc.h when CONFIG_CC_OPTIMIZE_FOR_SIZE is set. And BTW only x86 and tile define ARCH_SUPPORTS_OPTIMIZED_INLINING, so the rest of the architectures are not affected anyway. -- Markus -- 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/