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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 8CDDDC433DF for ; Mon, 13 Jul 2020 14:06:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6188B206F0 for ; Mon, 13 Jul 2020 14:06:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dU+8SVFw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729857AbgGMOG2 (ORCPT ); Mon, 13 Jul 2020 10:06:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729659AbgGMOG2 (ORCPT ); Mon, 13 Jul 2020 10:06:28 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 40937C061755 for ; Mon, 13 Jul 2020 07:06:28 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id g75so13426842wme.5 for ; Mon, 13 Jul 2020 07:06:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=AYBT93/x6rrYq9RPd2K35aqbqlGYbFacLRXNWsdWgbc=; b=dU+8SVFwmJ267v2437oNfANVH0w+KtdmF9nlS2MFnrlicHxPWJba+nGK3mBC1/TMue lfjmeyk2ndOV4n+34k+r2FM1693H8W0za4PmgmOmiWm+EdpE+ewUND7/X4bUSYs0ourB sqAPho5W/cEVWxjkjy1ueK9vvnSrtfhsSw9XN8adimyJbzDhXoeREA+KQUXb4NAeSnCn Nuhn4lgVc9NCG2mO9w/SJu8mWyOHAM+C6WZce27gosSNTyOf16LEN+e/ST1rlpK3C69D F4x+M67cw1w8E3e+JyVfa3WjN8acPOkjrWhuqpJ2O0XXkiVWNhPBjWmN0RztZYtp34Vc WnfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=AYBT93/x6rrYq9RPd2K35aqbqlGYbFacLRXNWsdWgbc=; b=iKolf61+WU1g8lfhxaTfbvuIKGpoGvHO4lMgnuTu1yA6WLZnCVho1OAANB9HcY9eFJ kMBorLD70qZrsrZpMb0Ij5AtRrTMKlWC0PzmYEuUETEMBzmGRtSNvcwgYjHcN4zjtWN2 tRDyKKKU3R29v+Mvh6ZFbMGZVudYtvvkXwYfkSnqhgVT8+NllFZmW5Jj2F+Jfg/pUyg3 yGYn/roC1KXaY7NSfogt2fSo+WRUKVaT8LcL6lRsNAaTarVaLaLEdKTT+BARbMWEtVaU ffgDEVF/eHBFcyzCKzGntvQjMPCQm2CCqQHVV8njG6wZxHZk+VZBCTnwADrNueDB1TCr 9jYg== X-Gm-Message-State: AOAM531K7OLs04VnBZ2KHdHUII5CqqDUT9HcZqwWwOY6g+sLSfpSBmyN dKxZsm1O/XF+plUmIfZ8/A== X-Google-Smtp-Source: ABdhPJz3OFpkcawfZxoAkzyzpvPTTaS800Rls2LKkpXfbGS8hiN+ULKhhCWMIwYbyBMRLsJTLf4Qdg== X-Received: by 2002:a1c:80d3:: with SMTP id b202mr120710wmd.111.1594649186814; Mon, 13 Jul 2020 07:06:26 -0700 (PDT) Received: from localhost.localdomain ([46.53.252.34]) by smtp.gmail.com with ESMTPSA id 51sm25807572wrc.44.2020.07.13.07.06.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2020 07:06:25 -0700 (PDT) Date: Mon, 13 Jul 2020 17:06:24 +0300 From: Alexey Dobriyan To: Peter Zijlstra Cc: mingo@redhat.com, will@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rwsem: fix commas in initialisation Message-ID: <20200713140624.GA17904@localhost.localdomain> References: <20200711145954.GA1178171@localhost.localdomain> <20200713115141.GH10769@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200713115141.GH10769@hirez.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 13, 2020 at 01:51:41PM +0200, Peter Zijlstra wrote: > On Sat, Jul 11, 2020 at 05:59:54PM +0300, Alexey Dobriyan wrote: > > Leading comma prevents arbitrary reordering of initialisation clauses. > > The whole point of C99 initialisation is to allow any such reordering. > > I'm conflicted on this argument, the only reason I'd be inclined to take > this patch is that it allows fixing the initialization order to not be > random. Yes, this is how the issue was noticed. > That is, I'd fold in the below. > > --- a/include/linux/rwsem.h > +++ b/include/linux/rwsem.h > @@ -89,9 +89,9 @@ static inline int rwsem_is_locked(struct > #define __RWSEM_INITIALIZER(name) \ > { __RWSEM_INIT_COUNT(name), \ > .owner = ATOMIC_LONG_INIT(0), \ > - .wait_list = LIST_HEAD_INIT((name).wait_list), \ > - .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock),\ > __RWSEM_OPT_INIT(name) \ > + .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock),\ > + .wait_list = LIST_HEAD_INIT((name).wait_list), \ One less chunk to compile with g++, a billion to go :^)