Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756200Ab3JHTtb (ORCPT ); Tue, 8 Oct 2013 15:49:31 -0400 Received: from mail-vb0-f52.google.com ([209.85.212.52]:33874 "EHLO mail-vb0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755505Ab3JHTta (ORCPT ); Tue, 8 Oct 2013 15:49:30 -0400 MIME-Version: 1.0 In-Reply-To: <20131008193507.GA10145@redhat.com> References: <20131005234430.GA22485@localhost> <20131008075151.GA15689@localhost> <20131008185154.GA8258@redhat.com> <20131008190523.GW30970@tucnak.zalov.cz> <20131008193507.GA10145@redhat.com> Date: Tue, 8 Oct 2013 12:49:29 -0700 X-Google-Sender-Auth: I2cgxbtjutmv4paYlEpjU1gpNOw Message-ID: Subject: Re: [x86] BUG: unable to handle kernel paging request at 00740060 From: Linus Torvalds To: Oleg Nesterov Cc: Jakub Jelinek , Fengguang Wu , Richard Henderson , Peter Zijlstra , Ingo Molnar , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1101 Lines: 28 On Tue, Oct 8, 2013 at 12:35 PM, Oleg Nesterov wrote: > > Cough... sorry for off-topic question, > > static inline int test_and_set_bit(long nr, volatile unsigned long *addr) > { > int oldbit; > > asm volatile(LOCK_PREFIX "bts %2,%1\n\t" > "sbb %0,%0" : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); > > doesn't this mean that "ADDR" doesn't need "+" as well? We use ADDR for some of the non-barrier ones too, that don't have the barrier. See clear_bit() and friends.. > Or at least, perhaps it makes sense to identify the include file which > makes the difference. Say, revert the changes in bitops.h, retest, then > in atomic.h if the kernel still fails, etc. Yeah, except Fengguang is the only one seeing this in his automated tests.. Linus -- 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/