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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9575AC433F5 for ; Wed, 29 Sep 2021 10:10:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2929B613D3 for ; Wed, 29 Sep 2021 10:10:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 2929B613D3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id C1A9594001A; Wed, 29 Sep 2021 06:10:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BCAA26B0087; Wed, 29 Sep 2021 06:10:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AE03994001A; Wed, 29 Sep 2021 06:10:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0144.hostedemail.com [216.40.44.144]) by kanga.kvack.org (Postfix) with ESMTP id 9E76E6B0085 for ; Wed, 29 Sep 2021 06:10:35 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 63AD239468 for ; Wed, 29 Sep 2021 10:10:35 +0000 (UTC) X-FDA: 78640191630.14.135DA7E Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf05.hostedemail.com (Postfix) with ESMTP id 16DF0506799B for ; Wed, 29 Sep 2021 10:10:34 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id C5A1960FE8; Wed, 29 Sep 2021 10:10:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632910234; bh=6IHLSvP1ghkbN4FLAePFphEp0d1TKXf3K9nSYoznCts=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=S1V/sH/4H3EJ/BmcXmIZpvD4yVuGZuAfNQdj2vBTZQsBId/EZCvalXaGyiKVKz+Ec 5aVsReMKETH94yaATug7Gv5l9OsGW8y0PjnyqCNhOW8VGm1yd6GYJ5HPKSg2+5MWmK tT+ScPofCmeYdR+HpNim8sn3bnNAnpftwVWL+YR9xTa1VnllfApPT2dSKOLRy6tBmL scKLgM/douszxH6mFYLpAO+dLzIkScz5mMBZ2kuV6l6wgM6nYJKw0nKlSfDQC9oB/7 x4hrUCcjBjqMpZ6inq6C+sP0uUrvHRFAW26lJODv2oYEOPCf/9mYiaRMMIXpYAw3UI POfPtCyNgrASA== Date: Wed, 29 Sep 2021 11:10:29 +0100 From: Will Deacon To: Chris Goldsworthy Cc: Catalin Marinas , Andrew Morton , David Hildenbrand , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sudarshan Rajagopalan Subject: Re: [RFC] arm64: mm: update max_pfn after memory hotplug Message-ID: <20210929101028.GB21057@willie-the-truck> References: <595d09279824faf1f54961cef52b745609b05d97.1632437225.git.quic_cgoldswo@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <595d09279824faf1f54961cef52b745609b05d97.1632437225.git.quic_cgoldswo@quicinc.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Queue-Id: 16DF0506799B X-Stat-Signature: 3xtjn6ycecip79zwqig5fcxf7smnzpzw Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="S1V/sH/4"; spf=pass (imf05.hostedemail.com: domain of will@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=will@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspamd-Server: rspam06 X-HE-Tag: 1632910234-495281 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Sep 23, 2021 at 03:54:48PM -0700, Chris Goldsworthy wrote: > From: Sudarshan Rajagopalan > > After new memory blocks have been hotplugged, max_pfn and max_low_pfn > needs updating to reflect on new PFNs being hot added to system. > > Signed-off-by: Sudarshan Rajagopalan > Signed-off-by: Chris Goldsworthy > --- > arch/arm64/mm/mmu.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index cfd9deb..fd85b51 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size, > if (ret) > __remove_pgd_mapping(swapper_pg_dir, > __phys_to_virt(start), size); > + else { > + max_pfn = PFN_UP(start + size); > + max_low_pfn = max_pfn; > + } We use 'max_pfn' as part of the argument to set_max_mapnr(). Does that need updating as well? Do we have sufficient locking to ensure nobody is looking at max_pfn or max_low_pfn while we update them? Will