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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7AE8C36000 for ; Fri, 21 Mar 2025 16:40:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7F413280002; Fri, 21 Mar 2025 12:40:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7A2F0280001; Fri, 21 Mar 2025 12:40:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 66B69280002; Fri, 21 Mar 2025 12:40:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 4918A280001 for ; Fri, 21 Mar 2025 12:40:41 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 81D11B3DF1 for ; 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charset=us-ascii Content-Disposition: inline In-Reply-To: <20250321070019.1271859-1-quic_zhenhuah@quicinc.com> X-Rspamd-Server: rspam01 X-Stat-Signature: hepumj7pscxsrzi4hfbt3489ygr44k3e X-Rspam-User: X-Rspamd-Queue-Id: B7637C000B X-HE-Tag: 1742575239-664354 X-HE-Meta: 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 Q9qskPDz YkONzUGXp0yz0ajTisO0sUSvfLeqh3SYpNnqFvw4t45Qg4cIt/cbSMDD/4l4Ye4gqLytHjBG+LsalBj9vkO7uwHvj4ETZDtD45A8a3DybDeN6+62dmKsHGOgD4+DCe1JqduZ+rRTLOoPor96k1FThua99HonnUpY3/spxCkC3r66p1fdhcAnFVmOe6pF6vezFNpi89Hnzsjmzz0bfLVylRhlsh/sDeR3sB9hQAta8RTa87Sfc1G3qu7wwjolRfmyQHTUh4cNs+q4R6DtSoDszYN5fcKNnSvzKnTrIk5jSQOsvzDdWZhahzcd6rHGFAQhDwFv6rbO8qPtFce+1fz8PgKsy9MRSKjUGsitueE/OksbFu+ccFUm55lIhBuRXqjxIBEWmiji+wa6tRw9CoOQiNv1x4xUzzAFi/kndXyIYZT2bPrImo6zy/aFBprMD6GGpMBLfSPTmi2eDMUpy073fYRgsi4LaG5pvKXEup1IcCf4ioaM= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Mar 21, 2025 at 03:00:19PM +0800, Zhenhua Huang wrote: > Hotplugged memory can be smaller than the original memory. For example, > on my target: > > root@genericarmv8:~# cat /sys/kernel/debug/memblock/memory > 0: 0x0000000064005000..0x0000000064023fff 0 NOMAP > 1: 0x0000000064400000..0x00000000647fffff 0 NOMAP > 2: 0x0000000068000000..0x000000006fffffff 0 DRV_MNG > 3: 0x0000000088800000..0x0000000094ffefff 0 NONE > 4: 0x0000000094fff000..0x0000000094ffffff 0 NOMAP > max_pfn will affect read_page_owner. Therefore, it should first compare and > then select the larger value for max_pfn. > > Fixes: 8fac67ca236b ("arm64: mm: update max_pfn after memory hotplug") > Signed-off-by: Zhenhua Huang > --- > arch/arm64/mm/mmu.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 1dfe1a8efdbe..310ff75891ef 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -1361,7 +1361,8 @@ int arch_add_memory(int nid, u64 start, u64 size, > __remove_pgd_mapping(swapper_pg_dir, > __phys_to_virt(start), size); > else { > - max_pfn = PFN_UP(start + size); > + /* Address of hotplugged memory can be smaller */ > + max_pfn = max(max_pfn, PFN_UP(start + size)); > max_low_pfn = max_pfn; > } I think this makes sense and also matches what x86 does. I'll queue it at -rc1 as a fix. Thanks. -- Catalin