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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 36F8BC433ED for ; Tue, 18 May 2021 09:28:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF45861073 for ; Tue, 18 May 2021 09:28:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347872AbhERJ3l (ORCPT ); Tue, 18 May 2021 05:29:41 -0400 Received: from mx2.suse.de ([195.135.220.15]:44376 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240100AbhERJ3i (ORCPT ); Tue, 18 May 2021 05:29:38 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 60CE4AE8D; Tue, 18 May 2021 09:28:19 +0000 (UTC) Subject: Re: [PATCH v3] mm, slub: change run-time assertion in kmalloc_index() to compile-time To: Nathan Chancellor , Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: 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: Vlastimil Babka Message-ID: <71416382-2e4c-5e03-df9c-265fda41c2de@suse.cz> Date: Tue, 18 May 2021 11:28:17 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/18/21 2:43 AM, Nathan Chancellor wrote: > 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? Good spot. > 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? Yes. > 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. At this point a fixup is the usual way. Andrew might squash it to the original patch (also with Marco's fixup) before sending to Linus. >>> 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(); >