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=-12.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URG_BIZ, URIBL_BLOCKED,USER_AGENT_SANE_1 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 4E1DFC433E0 for ; Tue, 2 Jun 2020 15:56:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02EC62067B for ; Tue, 2 Jun 2020 15:56:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591113415; bh=8fvhpfpA1qvs2hvGLQ7gRxnmKt53Z5/S7qNNylRwJeY=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=ulvAc2tGCLtHsMtfT4M2JxHCnXnYaCzW2/HDbUEK8CYtUvWTnpnLrss/JwyAgfxCO Di80I9kfCW+gWg8eV5YJi4jp1GTuDSAxnJ6S7b4LqEIniVrT3RK7h3qodUoyV3UKPi bXUHtQb12m2HhxjPfopFO2v/egqRbTyCTFyeKK7k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727773AbgFBP4y (ORCPT ); Tue, 2 Jun 2020 11:56:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:51360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726112AbgFBP4y (ORCPT ); Tue, 2 Jun 2020 11:56:54 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (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 24CBB20674; Tue, 2 Jun 2020 15:56:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591113413; bh=8fvhpfpA1qvs2hvGLQ7gRxnmKt53Z5/S7qNNylRwJeY=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=i64rcCVbR98JwyF4v7UYUrSghYOOQv+xUSNJp+9P0nh2NbLFAtBGlHb19sUfkalDL +I78+WFSo3g/v73Ec2qLuubF5SnibvDBqlm6cfBmZ6Ml+siwl1dHcA/qGQAEN0BMtY /BxCdS1SCiKwmYsUGhHMvLAaSy3kUy4GEzauE1WI= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 16B69352283B; Tue, 2 Jun 2020 08:56:53 -0700 (PDT) Date: Tue, 2 Jun 2020 08:56:53 -0700 From: "Paul E. McKenney" To: Geert Uytterhoeven Cc: Ingo Molnar , Linux Kernel Mailing List , linux-tip-commits@vger.kernel.org, "Joel Fernandes (Google)" , x86 Subject: Re: [PATCH] rcu/performance: Fix kfree_perf_init() build warning on 32-bit kernels Message-ID: <20200602155653.GG29598@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <158923078019.390.12609597570329519463.tip-bot2@tip-bot2> <20200526182744.GA3722128@gmail.com> <20200526191408.GN2869@paulmck-ThinkPad-P72> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 02, 2020 at 11:57:51AM +0200, Geert Uytterhoeven wrote: > Hi Paul, > > On Tue, May 26, 2020 at 9:17 PM Paul E. McKenney wrote: > > On Tue, May 26, 2020 at 08:27:44PM +0200, Ingo Molnar wrote: > > > * tip-bot2 for Joel Fernandes (Google) wrote: > > > > > > > The following commit has been merged into the core/rcu branch of tip: > > > > > > > > Commit-ID: f87dc808009ac86c790031627698ef1a34c31e25 > > > > Gitweb: https://git.kernel.org/tip/f87dc808009ac86c790031627698ef1a34c31e25 > > > > Author: Joel Fernandes (Google) > > > > AuthorDate: Mon, 16 Mar 2020 12:32:26 -04:00 > > > > Committer: Paul E. McKenney > > > > CommitterDate: Mon, 27 Apr 2020 11:02:50 -07:00 > > > > > > > > rcuperf: Add ability to increase object allocation size > > > > > > > > This allows us to increase memory pressure dynamically using a new > > > > rcuperf boot command line parameter called 'rcumult'. > > > > > > > > Signed-off-by: Joel Fernandes (Google) > > > > Signed-off-by: Paul E. McKenney > > > > --- > > > > kernel/rcu/rcuperf.c | 5 ++++- > > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c > > > > index a4a8d09..16dd1e6 100644 > > > > --- a/kernel/rcu/rcuperf.c > > > > +++ b/kernel/rcu/rcuperf.c > > > > > @@ -722,6 +723,8 @@ kfree_perf_init(void) > > > > schedule_timeout_uninterruptible(1); > > > > } > > > > > > > > + pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj)); > > > > > > There's a new build warning on certain 32-bit kernel builds due to > > > this commit: > > > > > > In file included from ./include/linux/printk.h:7, > > > from ./include/linux/kernel.h:15, > > > from kernel/rcu/rcuperf.c:13: > > > kernel/rcu/rcuperf.c: In function ‘kfree_perf_init’: > > > ./include/linux/kern_levels.h:5:18: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘unsigned int’ [-Wformat=] > > > 5 | #define KERN_SOH "\001" /* ASCII Start Of Header */ > > > | ^~~~~~ > > > ./include/linux/kern_levels.h:9:20: note: in expansion of macro ‘KERN_SOH’ > > > 9 | #define KERN_ALERT KERN_SOH "1" /* action must be taken immediately */ > > > | ^~~~~~~~ > > > ./include/linux/printk.h:295:9: note: in expansion of macro ‘KERN_ALERT’ > > > 295 | printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__) > > > | ^~~~~~~~~~ > > > kernel/rcu/rcuperf.c:726:2: note: in expansion of macro ‘pr_alert’ > > > 726 | pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj)); > > > | ^~~~~~~~ > > > kernel/rcu/rcuperf.c:726:32: note: format string is defined here > > > 726 | pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj)); > > > | ~~^ > > > | | > > > | long unsigned int > > > | %u > > This issue is now upstream. > > > > The reason for the warning is that both kfree_mult and sizeof() are > > > 'int' types on 32-bit kernels, while the format string expects a long. > > sizeof() is of type size_t, which is either unsigned int (32-bit) or > unsigned long (64-bit). > Hence the result of the multiplication is also of type size_t. > > > > > > > Instead of casting the type to long or tweaking the format string, the > > > most straightforward solution is to upgrade kfree_mult to a long. > > > Since this depends on CONFIG_RCU_PERF_TEST > > So the proper fix is Kefeng's patch from April: > "[PATCH -next] rcuperf: Fix printk format warning" > https://lore.kernel.org/r/20200417040245.66382-1-wangkefeng.wang@huawei.com Apologies for not having followed up on this one. I applied this commit and sent the pull request, CCing you. Thanx, Paul > ":"-- > > Makes sense, and I have queued the patch below, which I am assuming > > that you want in the upcoming merge window. If you don't tell me > > otherwise, I will send you an urgent pull request later today. > > Or, if you just put it directly into -tip yourself: > > > > Reviewed-by: Paul E. McKenney > > > > Either way, please let me know. > > > > > BTW., could we please also rename this code from 'PERF_TEST'/'perf test' > > > to 'PERFORMANCE_TEST'/'performance test'? At first glance I always > > > mistakenly believe that it's somehow related to perf, while it isn't. =B-) > > > > Fair enough, especially given that perf was there first and is also way > > more heavily used. ;-) > > > > But I am guessing that this one is OK for the v5.9 merge window. > > Either way, I will update as you say. > > > > Thanx, Paul > > > > ------------------------------------------------------------------------ > > > > commit 2fbc7d67a2ed108e3ac63296670fecb3a42fddd0 > > Author: Ingo Molnar > > Date: Tue May 26 12:10:01 2020 -0700 > > > > rcuperf: Fix kfree_mult to match printk() format > > > > This commit changes the type of kfree_mult from int to long in order > > to match the printk() format on 32-bit systems. > > > > Reported-by: kbuild test robot > > Signed-off-by: Ingo Molnar > > Signed-off-by: Paul E. McKenney > > > > diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c > > index d906ca9..fb3a1f0 100644 > > --- a/kernel/rcu/rcuperf.c > > +++ b/kernel/rcu/rcuperf.c > > @@ -93,7 +93,7 @@ torture_param(bool, shutdown, RCUPERF_SHUTDOWN, > > torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); > > torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable"); > > torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?"); > > -torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate."); > > +torture_param(long, kfree_mult, 1, "Multiple of kfree_obj size to allocate."); > > > > static char *perf_type = "rcu"; > > module_param(perf_type, charp, 0444); > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds