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 0F615C61DA3 for ; Tue, 21 Feb 2023 13:46:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233710AbjBUNqA (ORCPT ); Tue, 21 Feb 2023 08:46:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36392 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233404AbjBUNp7 (ORCPT ); Tue, 21 Feb 2023 08:45:59 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B154D1DB88 for ; Tue, 21 Feb 2023 05:45:58 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3ED3B6100E for ; Tue, 21 Feb 2023 13:45:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49658C433D2; Tue, 21 Feb 2023 13:45:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1676987157; bh=faIXtInbZm/tiyABGFOeo9pgDsJBGd067oYQlGXgcuk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=1jrx1SGHOdCQIMVavpu0xgI/8CYdFkLwHNAClao/PBmqa4rymDEI2xE4uWojnhA06 XEnQRAyqx3ThfRNWf0f1gmG+t+h59jnYZcHxQrmCSd2/YqpKfBPTanendjr9QVQHYR y/u91U7iVo0tZFghwT0iBEOa8LQcnWhOcBEgFPS0= Date: Tue, 21 Feb 2023 14:45:55 +0100 From: Greg KH To: Srinivasarao Pathipati Cc: stable@vger.kernel.org Subject: Re: [PATCH V1] rcu-tasks: Fix build error Message-ID: References: <1676916839-32235-1-git-send-email-quic_c_spathi@quicinc.com> <72e8a2a5-8729-5551-563a-d8d7c143f527@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Feb 21, 2023 at 04:49:17PM +0530, Srinivasarao Pathipati wrote: > > On 2/21/2023 4:07 PM, Greg KH wrote: > > On Tue, Feb 21, 2023 at 02:57:15PM +0530, Srinivasarao Pathipati wrote: > > > On 2/21/2023 12:24 AM, Greg KH wrote: > > > > On Mon, Feb 20, 2023 at 11:43:59PM +0530, Srinivasarao Pathipati wrote: > > > > > Making show_rcu_tasks_rude_gp_kthread() function as 'inline' to > > > > > fix below compilation error. > > > > > This is applicable to only 5.10 kernels as code got modified > > > > > in latest kernels. > > > > > > > > > > In file included from kernel/rcu/update.c:579:0: > > > > > kernel/rcu/tasks.h:710:13: error: ‘show_rcu_tasks_rude_gp_kthread’ defined but not used [-Werror=unused-function] > > > > > static void show_rcu_tasks_rude_gp_kthread(void) {} > > > > > > > > > > Signed-off-by: Srinivasarao Pathipati > > > > > --- > > > > > kernel/rcu/tasks.h | 2 +- > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > > > diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h > > > > > index 8b51e6a..53ddb4e 100644 > > > > > --- a/kernel/rcu/tasks.h > > > > > +++ b/kernel/rcu/tasks.h > > > > > @@ -707,7 +707,7 @@ static void show_rcu_tasks_rude_gp_kthread(void) > > > > > #endif /* #ifndef CONFIG_TINY_RCU */ > > > > > #else /* #ifdef CONFIG_TASKS_RUDE_RCU */ > > > > > -static void show_rcu_tasks_rude_gp_kthread(void) {} > > > > > +static inline void show_rcu_tasks_rude_gp_kthread(void) {} > > > > > #endif /* #else #ifdef CONFIG_TASKS_RUDE_RCU */ > > > > > //////////////////////////////////////////////////////////////////////// > > > > > -- > > > > > 2.7.4 > > > > > > > > > What commit id caused this problem? > > > commit  (8344496e8b49c4122c1808d6cd3f8dc71bccb595 rcu-tasks: Conditionally > > > compile show_rcu_tasks_gp_kthreads()) introduced this issue > > So this has been around for a very very long time. > > > > Why is this suddenly an issue now, almost 3 years later? What changed > > to cause this to become an issue? > > > > And please put this information in the changelog text. > >  We observed this issue on Android kernels with arch=UM  after picking this > patch (3fe617ccafd6f5bb33c2391d6f4eeb41c1fd0151 Enable '-Werror' by default > for all kernel builds ) recently into Android kernels. But that commit is NOT in the 5.10.y tree, so why would we care about this problem in the 5.10.y tree? confused, greg k-h