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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F0AF1C54E5D for ; Mon, 18 Mar 2024 18:17:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=qqremeQL6oi1mDATYUcoxcO5TzVmM0oazJtj/K6X3Xg=; b=lrjp92/tA520iV 8MpFZGCarkQzxdDp8XIYMAa7P8Ewlfcabk1iv6LCdaHrBrVoZa5LC39Exlpx8ZYOnR8X9QIGUWAe8 uzbIKFmoKThe2DJzi0rv3FIIzdW4OZaHvOBlRPUjPvZMn88YKb0bG4+ZMhJkR8sgJk060jN34zQdH jrhUz8ZX+UuimnjMcxx4KH9uER1wCXZWDNhuD0isft71tJttDZtoAVxJ/Be1XkSWHWXxFAtajWrOp dQWTs0pbx/ZHuxPlyrQirQ/XPupdAaeEQ3B5iW+31PsKo/I0mBYb63L4292oACt18iakFEdnh4/NR Fgx0cn5UBQvy2sxsX6VQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmHYF-00000009dRc-3tEY; Mon, 18 Mar 2024 18:17:35 +0000 Received: from sin.source.kernel.org ([145.40.73.55]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmHYA-00000009dNq-43Md for linux-arm-kernel@lists.infradead.org; Mon, 18 Mar 2024 18:17:32 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id A9E7ECE0B26; Mon, 18 Mar 2024 18:17:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9D78C433C7; Mon, 18 Mar 2024 18:17:24 +0000 (UTC) Date: Mon, 18 Mar 2024 18:17:22 +0000 From: Catalin Marinas To: Mark Rutland , "Christoph Lameter (Ampere)" Cc: Will Deacon , Jonathan.Cameron@huawei.com, Matteo.Carlini@arm.com, akpm@linux-foundation.org, anshuman.khandual@arm.com, Eric Mackay , dave.kleikamp@oracle.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux@armlinux.org.uk, robin.murphy@arm.com, vanshikonda@os.amperecomputing.com, yang@os.amperecomputing.com, Valentin Schneider Subject: Re: [PATCH v3] ARM64: Dynamically allocate cpumasks and increase supported CPUs to 512 Message-ID: References: <37099a57-b655-3b3a-56d0-5f7fbd49d7db@gentwo.org> <170983839495.1825460.8461454086733296317.b4-ty@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <170983839495.1825460.8461454086733296317.b4-ty@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240318_111731_208285_290EF7DB X-CRM114-Status: GOOD ( 16.77 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Mar 07, 2024 at 07:07:07PM +0000, Catalin Marinas wrote: > On Wed, 06 Mar 2024 17:45:04 -0800, Christoph Lameter (Ampere) wrote: > > Currently defconfig selects NR_CPUS=256, but some vendors (e.g. Ampere > > Computing) are planning to ship systems with 512 CPUs. So that all CPUs on > > these systems can be used with defconfig, we'd like to bump NR_CPUS to 512. > > Therefore this patch increases the default NR_CPUS from 256 to 512. > > > > As increasing NR_CPUS will increase the size of cpumasks, there's a fear that > > this might have a significant impact on stack usage due to code which places > > cpumasks on the stack. To mitigate that concern, we can select > > CPUMASK_OFFSTACK. As that doesn't seem to be a problem today with > > NR_CPUS=256, we only select this when NR_CPUS > 256. > > > > [...] > > Applied to arm64 (for-next/misc), thanks! > > I dropped the config entry and comment, replaced it with a select as per > Mark's suggestion. > > [1/1] ARM64: Dynamically allocate cpumasks and increase supported CPUs to 512 > https://git.kernel.org/arm64/c/0499a78369ad I re-instated this patch in arm64 for-next/core as: https://git.kernel.org/arm64/c/3fbd56f0e7c1 -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel