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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3AAA0C433F5 for ; Tue, 22 Mar 2022 22:20:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237844AbiCVWVf (ORCPT ); Tue, 22 Mar 2022 18:21:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230336AbiCVWVd (ORCPT ); Tue, 22 Mar 2022 18:21:33 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8DEDCDF2B for ; Tue, 22 Mar 2022 15:20:04 -0700 (PDT) Received: from zn.tnic (p200300ea971561dc329c23fffea6a903.dip0.t-ipconnect.de [IPv6:2003:ea:9715:61dc:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 540D51EC0528; Tue, 22 Mar 2022 23:19:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1647987597; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=+wLjXHgWZkMwbEKVBxHxrfvtzB2gVmwUl628XukYUD0=; b=NBIuBzJXz0docrwg/JsRQuvD5mehP+VRjDQ3JFfC7MkCaGbNiPQytJrOBtMDJaPmzxeb09 AidKrgTofsGhYuda8lNll8cclIl132FIoLQNGywKtsgB5DpmhpWFUc7sO92EZNtDtXYo8Y Alug83kl2S3AtYfWWSkF7Fx4FZBJPsM= Date: Tue, 22 Mar 2022 23:19:52 +0100 From: Borislav Petkov To: Linus Torvalds Cc: Ingo Molnar , Linux Kernel Mailing List , Peter Zijlstra , Will Deacon , Waiman Long , Boqun Feng , Thomas Gleixner , Andrew Morton , Sebastian Andrzej Siewior Subject: Re: [GIT PULL] locking changes for v5.18 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org + Sebastian. On Tue, Mar 22, 2022 at 03:05:39PM -0700, Linus Torvalds wrote: > On Mon, Mar 21, 2022 at 4:11 AM Ingo Molnar wrote: > > > > Sebastian Andrzej Siewior (2): > > locking/local_lock: Make the empty local_lock_*() function a macro. > > Grr. I noticed this too late, but this one actually breaks the build with clang. > > Why? > > Because it's now a macro, it doesn't use the argument at all, and you get: > > mm/page_alloc.c:131:40: error: variable 'pagesets' is not needed > and will not be emitted [-Werror,-Wunneeded-internal-declaration] > static DEFINE_PER_CPU(struct pagesets, pagesets) = { > ^ > > and I'm not sure why this doesn't show up with gcc, but apparently gcc > only warns about unused static functions, not unused static data. > > Or maybe gcc considers it used just because somebody did a typeof on it. > > I thought -tip had started checking with clang, but apparently not. As a matter of fact, I do see this in my builds: mm/page_alloc.c:131:40: warning: variable 'pagesets' is not needed and will not be emitted [-Wunneeded-internal-declaration] static DEFINE_PER_CPU(struct pagesets, pagesets) = { ^ 1 warning generated. but I dismissed it as one of those not-in-tip-area warnings. Sorry about that, I'll try to pay more attention in the future. > I see that the -mm tree has a fix for this, but I'm rather unhappy > that the -tip tree build checking has deteriorated so much, and clang > builds will now have a pointless build error that will cause issues > for bisect. Ah, you say build error because you have CONFIG_WERROR=y. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette