From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4311EC46460 for ; Tue, 14 Aug 2018 17:24:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8FAD2172B for ; Tue, 14 Aug 2018 17:24:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D8FAD2172B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388067AbeHNUNC (ORCPT ); Tue, 14 Aug 2018 16:13:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:45410 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387747AbeHNUNB (ORCPT ); Tue, 14 Aug 2018 16:13:01 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 90C5721728; Tue, 14 Aug 2018 17:24:55 +0000 (UTC) Date: Tue, 14 Aug 2018 13:24:53 -0400 From: Steven Rostedt To: "Paul E. McKenney" Cc: joel@joelfernandes.org, mathieu.desnoyers@efficios.com, peterz@infradead.org, tj@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC] Make call_srcu() available during very early boot Message-ID: <20180814132453.093a4921@gandalf.local.home> In-Reply-To: <20180814170618.GA24813@linux.vnet.ibm.com> References: <20180814162448.GA20414@linux.vnet.ibm.com> <20180814124945.5cf1753f@gandalf.local.home> <20180814170618.GA24813@linux.vnet.ibm.com> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 14 Aug 2018 10:06:18 -0700 "Paul E. McKenney" wrote: > > > #define __SRCU_STRUCT_INIT(name, pcpu_name) \ > > > - { \ > > > - .sda = &pcpu_name, \ > > > - .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ > > > - .srcu_gp_seq_needed = 0 - 1, \ > > > - __SRCU_DEP_MAP_INIT(name) \ > > > - } > > > +{ \ > > > + .sda = &pcpu_name, \ > > > + .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ > > > + .srcu_gp_seq_needed = 0 - 1, \ > > > > Interesting initialization of -1. This was there before, but still > > interesting none the less. > > If I recall correctly, this subterfuge suppresses compiler complaints > about initializing an unsigned long with a negative number. :-/ Did you try: .srcu_gp_seq_needed = -1UL, ? -- Steve