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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3BCEBCA0EED for ; Fri, 22 Aug 2025 17:02:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 63BBA440151; Fri, 22 Aug 2025 13:02:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5E6798E009D; Fri, 22 Aug 2025 13:02:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4D543440151; Fri, 22 Aug 2025 13:02:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 3D2BD8E009D for ; Fri, 22 Aug 2025 13:02:23 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 03328160285 for ; Fri, 22 Aug 2025 17:02:22 +0000 (UTC) X-FDA: 83805011766.03.17403D8 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf22.hostedemail.com (Postfix) with ESMTP id 58B54C0020 for ; Fri, 22 Aug 2025 17:02:21 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="X/RxlEh5"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf22.hostedemail.com: domain of sj@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sj@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1755882141; a=rsa-sha256; cv=none; b=79QHtFNmLQsgAV8DQyn2SjArxqJzBT0JBRI/0DGzT4N04bG/PwRrNM0ybvjE+LjtJUB/vx dP7vijJ8LZYzP25K9fD1eaSnuhkaZuz6JlHYsxUqzD9udbCDSgfez+NP1cBiHRv6Fy5CTM tIocChcx9sCVX90DbQ+6Bwcxl0AcFS4= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="X/RxlEh5"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf22.hostedemail.com: domain of sj@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sj@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1755882141; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=772vGqxA65bz16ef3P0OZqzhHKKFfpAXON1zFoQmwHM=; b=d9ScS/9VNU9IYU7tqqQYz8i9L7aqWcHiNjkJ4R1TqwlT0KHc2LPS4M1jhxVb76IghTZgCo qADjJt9+2hInlorBsMMY2Gg1O4RA6x9R5H/ZRqSmuQReooNufOapJOWizyGr/VpYsFV8sj 1jp3WkY8f8VNfwqbAulER9PYJ7lMosA= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 64D49601E7; Fri, 22 Aug 2025 17:02:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7EA9C4CEED; Fri, 22 Aug 2025 17:02:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755882140; bh=N43GnKy17u3pJmuxA0B+CvRzCGT4IjO9pWdh50KAxp8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X/RxlEh56SJyKzLLReKVy9zMR7Rn10sDZ2qGXdgaqLeUy++5vRLbAaO8F1sq4dW3A FVPFAm1E1KDu+9/CVB8PArKdY0HRrXTU0L7mEy3QGm8oDmYlvLcPGrEnt/PdkJ5xtS WPwGxZiqHYuwlyrYRxRwfpMchkAzSUix0wgYLGwYkH8uFDFTTyuMLp6fHc+1uXHfs8 s+X5+H1F8hdQ3OyIBGTgvD5OcC7RDayM3+Gr4vyGqAtfAsaEK49eudKcHbm56kC8gk 8jVNP2cdHpsMgjezsa0xbQw1c8LogFjCAJQgvfQ9Um93+KYDxx0kQzjtsDqYPIARCs dvKAxgTXqd2AA== From: SeongJae Park To: David Hildenbrand Cc: SeongJae Park , linux-kernel@vger.kernel.org, Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , "David S. Miller" , Andreas Larsson , Alexander Potapenko , Andrew Morton , Brendan Jackman , Christoph Lameter , Dennis Zhou , Dmitry Vyukov , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, iommu@lists.linux.dev, io-uring@vger.kernel.org, Jason Gunthorpe , Jens Axboe , Johannes Weiner , John Hubbard , kasan-dev@googlegroups.com, kvm@vger.kernel.org, "Liam R. Howlett" , Linus Torvalds , linux-arm-kernel@axis.com, linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, linux-ide@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, Lorenzo Stoakes , Marco Elver , Marek Szyprowski , Michal Hocko , Mike Rapoport , Muchun Song , netdev@vger.kernel.org, Oscar Salvador , Peter Xu , Robin Murphy , Suren Baghdasaryan , Tejun Heo , virtualization@lists.linux.dev, Vlastimil Babka , wireguard@lists.zx2c4.com, x86@kernel.org, Zi Yan Subject: Re: [PATCH RFC 01/35] mm: stop making SPARSEMEM_VMEMMAP user-selectable Date: Fri, 22 Aug 2025 10:02:17 -0700 Message-Id: <20250822170217.53169-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250821200701.1329277-2-david@redhat.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 58B54C0020 X-Stat-Signature: 3kaou3k8se7fouib9eab33kr78757mbg X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1755882141-699416 X-HE-Meta: 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 UJE9m9K2 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 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 Thu, 21 Aug 2025 22:06:27 +0200 David Hildenbrand wrote: > In an ideal world, we wouldn't have to deal with SPARSEMEM without > SPARSEMEM_VMEMMAP, but in particular for 32bit SPARSEMEM_VMEMMAP is > considered too costly and consequently not supported. > > However, if an architecture does support SPARSEMEM with > SPARSEMEM_VMEMMAP, let's forbid the user to disable VMEMMAP: just > like we already do for arm64, s390 and x86. > > So if SPARSEMEM_VMEMMAP is supported, don't allow to use SPARSEMEM without > SPARSEMEM_VMEMMAP. > > This implies that the option to not use SPARSEMEM_VMEMMAP will now be > gone for loongarch, powerpc, riscv and sparc. All architectures only > enable SPARSEMEM_VMEMMAP with 64bit support, so there should not really > be a big downside to using the VMEMMAP (quite the contrary). > > This is a preparation for not supporting > > (1) folio sizes that exceed a single memory section > (2) CMA allocations of non-contiguous page ranges > > in SPARSEMEM without SPARSEMEM_VMEMMAP configs, whereby we > want to limit possible impact as much as possible (e.g., gigantic hugetlb > page allocations suddenly fails). > > Cc: Huacai Chen > Cc: WANG Xuerui > Cc: Madhavan Srinivasan > Cc: Michael Ellerman > Cc: Nicholas Piggin > Cc: Christophe Leroy > Cc: Paul Walmsley > Cc: Palmer Dabbelt > Cc: Albert Ou > Cc: Alexandre Ghiti > Cc: "David S. Miller" > Cc: Andreas Larsson > Signed-off-by: David Hildenbrand Acked-by: SeongJae Park Thanks, SJ [...]