Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934160AbaKSWOB (ORCPT ); Wed, 19 Nov 2014 17:14:01 -0500 Received: from www.linutronix.de ([62.245.132.108]:47836 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933300AbaKSWN7 (ORCPT ); Wed, 19 Nov 2014 17:13:59 -0500 Date: Wed, 19 Nov 2014 23:13:53 +0100 (CET) From: Thomas Gleixner To: Andy Lutomirski cc: Dave Jones , Linus Torvalds , Don Zickus , Linux Kernel , x86@kernel.org, Peter Zijlstra Subject: Re: [PATCH] x86, syscall: Fix _TIF_NOHZ handling in syscall_trace_enter_phase1 In-Reply-To: Message-ID: References: <546D0530.8040800@mit.edu> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 19 Nov 2014, Andy Lutomirski wrote: > TIF_NOHZ is 19 (i.e. _TIF_SYSCALL_TRACE | _TIF_NOTIFY_RESUME | > _TIF_SINGLESTEP), not (1<<19). > > This code is involved in Dave's trinity lockup, but I don't see why > it would cause any of the problems he's seeing, except inadvertently > by causing a different path through entry_64.S's syscall handling. Right, while it is wrong it does not explain the wreckage on 3.17, which does not have that code. Thanks, tglx -- 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/