Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752905AbcDCJ7a (ORCPT ); Sun, 3 Apr 2016 05:59:30 -0400 Received: from www.linutronix.de ([62.245.132.108]:58630 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752533AbcDCJ72 (ORCPT ); Sun, 3 Apr 2016 05:59:28 -0400 Date: Sun, 3 Apr 2016 11:57:51 +0200 (CEST) From: Thomas Gleixner To: Andy Lutomirski cc: LKML , Sebastian Andrzej Siewior , Darren Hart , Peter Zijlstra , Ingo Molnar , Michael Kerrisk , Davidlohr Bueso , Chris Mason , "Carlos O'Donell" , Torvald Riegel , Eric Dumazet Subject: Re: [RFC patch 4/7] futex: Add support for attached futexes In-Reply-To: <57000D4B.5000406@kernel.org> Message-ID: References: <20160402095108.894519835@linutronix.de> <20160402110035.753145539@linutronix.de> <57000D4B.5000406@kernel.org> 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 Content-Length: 418 Lines: 14 On Sat, 2 Apr 2016, Andy Lutomirski wrote: > On 04/02/2016 04:09 AM, Thomas Gleixner wrote: > [omitted due to some Thunderbird bug, sigh] > > What happens if you mix attached an non-attached ops on the same futex? Not much. You might get an error code, sleep forever or the call will just result in a NOP wasting cpu cycles. That's the same when you mix shared/private operations on the same futex. Thanks, tglx