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 36452C4828D for ; Tue, 6 Feb 2024 23:18:35 +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=XGs1j4BwK0kLGXYSqX5nhfco4CI5m3Z8qO/eFBsAZ3E=; b=MBOOcfnGlAsCR+ Yd6uoTjrfS36o/Ih2lfsSUqzOKarUcbHNNdAgXH+fCplZ/KRWSX4UqOq5rasZ5U2DTVCzcHQHYhjz h8qbricNgWoRE00MHjF/qhOfoBBQVw6yW1KwvmIE2zwep5zVsiN+lVto/uwgG8ZRmbElqaDCTN13J 93xAPFqiyqRcq5CGxhR0JphpIFaJucd71e6x6vYAcRqsKyhPWEZ7lK77BKWCN0xMOIXbsomFji9qJ nXbJppyLkuQJfYN874WimY9dv9UL2kMCP99T5snfC3gcCwkQ1SjKLau+W6L130xvebfOXth6y5wHM 3CP0KMG+ssvlzw5pMamg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rXUhr-00000009AVE-3Tho; Tue, 06 Feb 2024 23:18:23 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rXUho-00000009AUf-3Ped for linux-arm-kernel@lists.infradead.org; Tue, 06 Feb 2024 23:18:22 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=DKdDlBaoWLD1i+SswtNzDM+hpIQ9ywhkR3LkK9m+G3w=; b=StElRlcSH9oSxj07zjDse4KeZb JMadwTYZgV3Oekw3j3odYlubfWwU2FxbHxxfvbtmPerYRfD2Fdz/rT5qsS/cYwagrYJqiUP9rnG6/ rRQnXey/kmQsTp1DUG7bi1vkNhSSGhbvkNmYGokw9mx12+pPUqUnMrLnZBFgzqIYXdZnfKAhL8isj 2S2hCuTWe5Mdcd19mk4IR4l80NSKrjqvRUpXfIfHS32mg01WRGowqs7MZbVshbCqrHQp/84zuJiIh TN1VWOm++QJRkeafxPtYvXNZAvhNga5IGoksfC4ys0rskp+Wol5sb4EV+vpkHX2Nh6+EhptKuBUMq bVdXUw0g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:39202) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1rXUhY-0002bh-1q; Tue, 06 Feb 2024 23:18:04 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1rXUhS-00040V-VN; Tue, 06 Feb 2024 23:17:59 +0000 Date: Tue, 6 Feb 2024 23:17:58 +0000 From: "Russell King (Oracle)" To: "Christoph Lameter (Ampere)" Cc: catalin.marinas@arm.com, Will Deacon , Jonathan.Cameron@huawei.com, Matteo.Carlini@arm.com, Valentin.Schneider@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, robin.murphy@arm.com, vanshikonda@os.amperecomputing.com, yang@os.amperecomputing.com Subject: Re: [PATCH REPOST v2] ARM64: Dynamically allocate cpumasks and increase supported CPUs to 512 Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240206_151820_875100_036EB04B X-CRM114-Status: GOOD ( 17.15 ) 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 Tue, Feb 06, 2024 at 10:09:59AM -0800, Christoph Lameter (Ampere) wrote: > Can we get this merged for 6.9? The patch has been around for awhile now. > > > > Ampere Computing develops high end ARM processor that support an ever > increasing number of processors. The default 256 processors are > not enough for our newer products. The default is used by > distros and therefore our customers cannot use distro kernels because > the number of processors is not supported. > > One of the objections against earlier patches to increase the limit > was that the memory use becomes too high. There is a feature called > CPUMASK_OFFSTACK that configures the cpumasks in the kernel to be > dynamically allocated. This was used in the X86 architecture in the > past to enable support for larger CPU configurations up to 8k cpus. > > With that is becomes possible to dynamically size the allocation of > the cpu bitmaps depending on the quantity of processors detected on > bootup. > > This patch enables that logic if more than 256 processors > are configured and increases the default to 512 processors. > > Further increases may be needed if ARM processor vendors start > supporting more processors. Given the current inflationary trends > in core counts from multiple processor manufacturers this may occur. > > Tested-by: Eric Mackay Reviewed-by: Russell King (Oracle) Thanks! > Signed-off-by: Christoph Lameter (Ampere) -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel