Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756209AbbHYTEp (ORCPT ); Tue, 25 Aug 2015 15:04:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33012 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755977AbbHYTEn (ORCPT ); Tue, 25 Aug 2015 15:04:43 -0400 Date: Tue, 25 Aug 2015 21:02:12 +0200 From: Oleg Nesterov To: "Paul E. McKenney" Cc: Mark Salter , Yoshinori Sato , uclinux-h8-devel@lists.sourceforge.jp, "linux-kernel@vger.kernel.org" , "Peter Zijlstra (Intel)" , Josh Triplett , Guenter Roeck Subject: Re: [PATCH] rcu: change _wait_rcu_gp() to work around gcc 67055 bug Message-ID: <20150825190212.GA16036@redhat.com> References: <55DB63AC.7070305@roeck-us.net> <8737z7nc7b.wl-ysato@users.sourceforge.jp> <1440512875.5882.16.camel@redhat.com> <55DC83C7.1060809@roeck-us.net> <20150825184518.GA15234@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150825184518.GA15234@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1127 Lines: 35 On 08/25, Oleg Nesterov wrote: > > The code like > > const int n = const-expr; > whatever_t array[n]; > > in inline function can confuse gcc, see > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67055#c13 > > This leads to > > In file included from include/linux/rcupdate.h:429:0, > from include/linux/rcusync.h:5, > from kernel/rcu/sync.c:1: > include/linux/rcutiny.h: In function 'rcu_barrier_sched': > include/linux/rcutiny.h:55:20: internal compiler error: Segmentation > fault > static inline void rcu_barrier_sched(void) > > build failure after ec90a194a "rcu: Create a synchronize_rcu_mult()" > and 114b7fd4b "rcu: Create rcu_sync infrastructure" meet each other. and just in case... make make kernel/rcu/rcutorture.o fails the same way if CONFIG_RCU_TORTURE_TEST && CONFIG_TINY_RCU. So we need a work- around even before/without rcu_sync. Oleg. -- 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/