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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 BA6B4C433E0 for ; Mon, 11 Jan 2021 18:04:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CC94223C8 for ; Mon, 11 Jan 2021 18:04:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389926AbhAKSEJ (ORCPT ); Mon, 11 Jan 2021 13:04:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732662AbhAKSEJ (ORCPT ); Mon, 11 Jan 2021 13:04:09 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 211ADC061786 for ; Mon, 11 Jan 2021 10:03:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description; bh=a5fVlDIRGDkfpBVFh+Is+SLiOkwkapO+PazwXN5JJkw=; b=RY9Oy9WyAsaW+tAPs2Ai9IKpB/ 4ZOSRY5kpQCPbHGbt3zoAZ6FZUbaBZGFGJTFxbrDWjGyG1cW+JAu8N72HkZg+TscaRLFSNFzxedXn E3De5LtCf5QBbUeClREBp0uVxl5/DqoLuYcWYdrg5SH8tKabMG9tsPC8jJmWDYIzZxVpcniohIzrL 9Jf/MGwYJrxq5b6+8hxIKO50bB5AkgiMfhtNE+wX7lohLg5RWjhQNkH7dZLGbAXTnz52yN2av2M/C Pa5tlywqqn9fx47Pchq+mQ/mK/ZSNzZuSmgN9RVOVjZr13wGSuvm7gYoyj+yTUWqCONNqn0CSh8jG i2ZncgyA==; Received: from [2601:1c0:6280:3f0::79df] by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kz1XH-0001b9-Rm; Mon, 11 Jan 2021 18:03:24 +0000 Subject: Re: [PATCH] arm64: Kconfig: Increase NR_CPUS default to 512 To: Vanshidhar Konda , Will Deacon Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, patches@amperecomputing.com References: <20210110053615.3594358-1-vanshikonda@os.amperecomputing.com> <20210111105636.GA7071@willie-the-truck> <20210111175741.ldifmv7uhdekbq5d@con01sys-r111.scc-lab.amperecomputing.com> From: Randy Dunlap Message-ID: Date: Mon, 11 Jan 2021 10:03:18 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <20210111175741.ldifmv7uhdekbq5d@con01sys-r111.scc-lab.amperecomputing.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/11/21 9:57 AM, Vanshidhar Konda wrote: > On Mon, Jan 11, 2021 at 10:56:36AM +0000, Will Deacon wrote: >> On Sat, Jan 09, 2021 at 09:36:15PM -0800, vanshikonda@os.amperecomputing.com wrote: >>> From: Vanshidhar Konda >>> >>> Increase the default value of NR_CPUS to 512 from 256. This will >>> enable the defconfig kernel to support platforms that have upto >>> 512 cores. >> >> Do we already support such a platform, and what is it? I'm fine with bumping. >> the number, it's just nice to be able to say specifically _why_ we're dong >> it. > > I'm not aware of any publicly available systems that run into the 256 > core limitation. At Ampere we have internal systems that would benefit > from this change as they support more than 256 cores. But what does that have to do with the default value? Do you expect to run defconfig kernels? I don't ever expect that. -- ~Randy