From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751755AbaESWqm (ORCPT ); Mon, 19 May 2014 18:46:42 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50203 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750868AbaESWqk (ORCPT ); Mon, 19 May 2014 18:46:40 -0400 Date: Mon, 19 May 2014 15:46:39 -0700 From: Andrew Morton To: Manfred Spraul Cc: LKML , Davidlohr Bueso , Michael Kerrisk , 1vier1@web.de Subject: Re: [PATCH 6/6] ipc/sem.c: make semctl(,,{GETNCNT,GETZCNT}) standard compliant Message-Id: <20140519154639.5570a30f8b47872a323dcdfd@linux-foundation.org> In-Reply-To: <1400399917-17583-7-git-send-email-manfred@colorfullife.com> References: <1400399917-17583-1-git-send-email-manfred@colorfullife.com> <1400399917-17583-2-git-send-email-manfred@colorfullife.com> <1400399917-17583-3-git-send-email-manfred@colorfullife.com> <1400399917-17583-4-git-send-email-manfred@colorfullife.com> <1400399917-17583-5-git-send-email-manfred@colorfullife.com> <1400399917-17583-6-git-send-email-manfred@colorfullife.com> <1400399917-17583-7-git-send-email-manfred@colorfullife.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 18 May 2014 09:58:37 +0200 Manfred Spraul wrote: > SUSv4 clearly defines how semncnt and semzcnt must be calculated: > A task waits on exactly one semaphore: > The semaphore from the first operation in the sop array that cannot proceed. > > The Linux implementation never followed the standard, it tried to count all > semaphores that might be the reason why a task sleeps. > > This patch fixes that. What are the back-compatibility implications of this change?