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=-12.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 4632DC433ED for ; Tue, 18 May 2021 00:43:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24E18613AC for ; Tue, 18 May 2021 00:43:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345080AbhERAoo (ORCPT ); Mon, 17 May 2021 20:44:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:44158 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239149AbhERAom (ORCPT ); Mon, 17 May 2021 20:44:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 22C0D60FF0; Tue, 18 May 2021 00:43:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621298605; bh=YhiRwfdTmsYWyIN8KfAxmHBe/njsn546d3dY8ADNxg4=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=JGZFQJSbnkMWdYXTittkfh+uDbQRsOYMx1H4lXaD1nBSB8bW6BDmQuUQJXbSsqt85 xNnv/7c1/Ax5CqCOE1xahL4hZ/GdNjVUMkuhNnoHnv7DQZLVMtqMKxT6AKD28Jf8Bc J8OcmJZXudlxVLPGxo/UhQiOLgpQrks6LHv0s/Zc5SquGlZg19Elntm/cBQODi0JWY gDVegA4O2FBp0KxhTR6karwrzp4l4z9I17S+1IZ7JpFnxHICY3mIsuX3Nes2ocrV8r VXQHET3d1VW9knKUMSlZ5y0gP/sdzviuAjrlarbCQETjva7/EGgYZZGTTGnlFf0+q6 Pb/ZPRE41MgKA== Subject: Re: [PATCH v3] mm, slub: change run-time assertion in kmalloc_index() to compile-time To: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Vlastimil Babka , akpm@linux-foundation.org, iamjoonsoo.kim@lge.com, rientjes@google.com, penberg@kernel.org, cl@linux.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, naresh.kamboju@linaro.org, clang-built-linux@googlegroups.com, linux-next@vger.kernel.org, ndesaulniers@google.com, lkft-triage@lists.linaro.org, sfr@canb.auug.org.au, arnd@arndb.de, Marco Elver References: <20210511173448.GA54466@hyeyoo> <20210515210950.GA52841@hyeyoo> <41c65455-a35b-3ad3-54f9-49ca7105bfa9@suse.cz> <20210518003859.GC80297@hyeyoo> From: Nathan Chancellor Message-ID: Date: Mon, 17 May 2021 17:43:22 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20210518003859.GC80297@hyeyoo> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/17/2021 5:38 PM, Hyeonggon Yoo wrote: > On Sat, May 15, 2021 at 11:34:49PM -0700, Nathan Chancellor wrote: >> This should work I think: > > compiled well with clang-10.0.1, clang-11.0.0, > and gcc-10.2.0 with x86_64 default config. > > is the condition CONFIG_CLANG_VERSION > 110000, > not including 110000 it self? Ah sorry, that should definitely be >= :( That is what I get for writing an email that late... in reality, it probably won't matter due to the availability of 11.0.1 and 11.1.0 but it should absolutely be changed. I have not given Nick's patch a go yet but would something like this be acceptable? If so, did you want me to send a formal fixup patch or did you want to send a v4? I have no personal preference. >> diff --git a/include/linux/slab.h b/include/linux/slab.h >> index 9d316aac0aba..1b653266f2aa 100644 >> --- a/include/linux/slab.h >> +++ b/include/linux/slab.h >> @@ -413,7 +413,7 @@ static __always_inline unsigned int __kmalloc_index(size_t size, >> if (size <= 16 * 1024 * 1024) return 24; >> if (size <= 32 * 1024 * 1024) return 25; >> >> - if (size_is_constant) >> + if ((IS_ENABLED(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION > 110000) && size_is_constant) >> BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); >> else >> BUG();