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[2620:137:e000::1:20]) by mx.google.com with ESMTP id x88-20020a50bae1000000b00418fc8a4b63si795282ede.529.2022.04.12.20.01.40; Tue, 12 Apr 2022 20:02:05 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=jKoueA3v; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230425AbiDMAVZ (ORCPT + 99 others); Tue, 12 Apr 2022 20:21:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230298AbiDMAVX (ORCPT ); Tue, 12 Apr 2022 20:21:23 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 636D33D4B1; Tue, 12 Apr 2022 17:19:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender :Reply-To:Content-ID:Content-Description; bh=1Cz3pjY7YWGZgp7PC+MmjSwo+jq8i41FSV3VLd7PWmA=; b=jKoueA3vIBVbIMNC4paBBsssl8 vRnbKfpWRA6IhPh4mPGpbcSRKafA3BtV3cydmjb+3FUPiC/iQBc97+jV8GzffjT5Xu3WyUg2A64vO 8RND7/DnVRAPics7QTspLje8T9hD8OK6/LYe0r5t2F4qOqofrtR+/ynC8s1b8JpzlbPUbEVWY6wH/ m1IO82IZuAFnWU4aeWOig+BpWErpUlUcI4PIYpDNJ8V7yCKv5JosVRpW9+nuRHHx2AWE3jfF1KDkP D7iYUeHCY25etWJ841FmCYOXLVFv/W1uyN2kS/g3DvGEr66+4GMvf7ZGiiHkSjTqeUuwvp1V/iGSZ zIfC3DmQ==; Received: from [2601:1c0:6280:3f0::aa0b] by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1neQih-00Do0t-8D; Wed, 13 Apr 2022 00:18:51 +0000 Message-ID: Date: Tue, 12 Apr 2022 17:18:45 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH RESEND 1/1] lib/Kconfig: remove DEBUG_PER_CPU_MAPS dependency for CPUMASK_OFFSTACK Content-Language: en-US To: Libo Chen , gregkh@linuxfoundation.org, masahiroy@kernel.org, tglx@linutronix.de, peterz@infradead.org, mingo@kernel.org, vbabka@suse.cz, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org References: <20220412231508.32629-1-libo.chen@oracle.com> <20220412231508.32629-2-libo.chen@oracle.com> From: Randy Dunlap In-Reply-To: <20220412231508.32629-2-libo.chen@oracle.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-5.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi-- On 4/12/22 16:15, Libo Chen wrote: > Forcing CPUMASK_OFFSTACK to be conditoned on DEBUG_PER_CPU_MAPS doesn't > make a lot of sense nowaday. Even the original patch dating back to 2008, > aab46da0520a ("cpumask: Add CONFIG_CPUMASK_OFFSTACK") didn't give any > rationale for such dependency. > > Nowhere in the code supports the presumption that DEBUG_PER_CPU_MAPS is > necessary for CONFIG_CPUMASK_OFFSTACK. Make no mistake, it's good to > have DEBUG_PER_CPU_MAPS for debugging purpose or precaution, but it's > simply not a hard requirement for CPUMASK_OFFSTACK. Moreover, x86 Kconfig > already can set CPUMASK_OFFSTACK=y without DEBUG_PER_CPU_MAPS=y. > There is no reason other architectures cannot given the fact that they > have even fewer, if any, arch-specific CONFIG_DEBUG_PER_CPU_MAPS code than > x86. > > Signed-off-by: Libo Chen > --- > lib/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/Kconfig b/lib/Kconfig > index 087e06b4cdfd..7209039dfb59 100644 > --- a/lib/Kconfig > +++ b/lib/Kconfig > @@ -511,7 +511,7 @@ config CHECK_SIGNATURE > bool > > config CPUMASK_OFFSTACK > - bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS This "if" dependency only controls whether the Kconfig symbol's prompt is displayed (presented) in kconfig tools. Removing it makes the prompt always be displayed. Any architecture could select (should be able to) CPUMASK_OFFSTACK independently of DEBUG_PER_CPU_MAPS. Is there another problem here? > + bool "Force CPU masks off stack" > help > Use dynamic allocation for cpumask_var_t, instead of putting > them on the stack. This is a bit more expensive, but avoids -- ~Randy