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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 10A8ECA0FFD for ; Fri, 29 Aug 2025 07:17:02 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D12EA10E04F; Fri, 29 Aug 2025 07:17:01 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="P/BEZEs1"; dkim-atps=neutral Received: from mail-ej1-f41.google.com (mail-ej1-f41.google.com [209.85.218.41]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4EA1110E6BE; Thu, 28 Aug 2025 07:18:53 +0000 (UTC) Received: by mail-ej1-f41.google.com with SMTP id a640c23a62f3a-afebb6d4093so95912966b.1; Thu, 28 Aug 2025 00:18:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1756365532; x=1756970332; darn=lists.freedesktop.org; h=user-agent:in-reply-to:content-disposition:mime-version:references :reply-to:message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=ACPidqQG6DQZNVxh12NaJPKP3Jkf06hyqyPjQ1p5F2E=; b=P/BEZEs1Gp1r8lAk7Cwq+2yuudfNPTcNyQGMrPYdRLVJ0w5lRWatxgwgtf+/XkdDYc jZX0Ble8qa8PBEIFGc94tjbAU4lc3AyAlmhnNljIbUZ8MqqG/TBMJJ3ePl7zAztQzNPo 1CcFcmtVC/ITAXdToEdjai460Fz0e+CM7NftwRXP8afXpmlAYdEmPCgTuAqDpJZQJKZC LuVIxGhJUvj80FXnSyvrta8DflvvhEwmtIVqnrUB6pPgyHvl+SYDOcCn/yGDSWZo8fGJ GjCsBW5NHE334IiIFAajvMr1iBpQG9GtlbwdDg7xzSpRnrR5bacP17YfMoMK5lhy/qTB M/sQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756365532; x=1756970332; h=user-agent:in-reply-to:content-disposition:mime-version:references :reply-to:message-id:subject:cc:to:from:date:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=ACPidqQG6DQZNVxh12NaJPKP3Jkf06hyqyPjQ1p5F2E=; b=m+5D+738Fv88i+G6BJqhahTZn/6faIcse5TaHVEORn5zInyLNPYZ0Y/2dQLv61NOWD mf6YuQKs5rCMPg37cyIKG7UBymrRh1KJKU67WOc5tCPGpwjeApqRC/ZNqtswTUBkzncj 32nGHg+mC0v55KW7nx7g0NTVvXdgWFYdK/lqT9DhwqDFHUXGVy7Ez9/9DYU4Ch10q3Nl VqKSd3nZajQQKDBauAv638dJZQ6taNVJRXFKYY+mnETXj+h1izZBArc5+8Bo63FbNXcm zG/02NFc63+s7ALEPMJ/qilc+fJqdRM+Wvqt235LAqygWmxOkVvtEpnDek4sS+1zsPzw 9JrQ== X-Forwarded-Encrypted: i=1; AJvYcCUL1PVRxCClDFUViv4sE/U5WpDE99iDS0bGHCwPPjK20SA9bx6pJnf67fZJr1vD7IE3fMtTZ6QPCf4T@lists.freedesktop.org, AJvYcCW7LpRJaGI+Hn21ixOqedgKIOYqUbA56t46p2qBICyRUh5BqqUjtqjO+kNXjTGJbBh0AJ5X7VxGkbA=@lists.freedesktop.org X-Gm-Message-State: AOJu0YwWK/adrI9sWY2ojgcpgCUMExa5hVLgzKVuvTgfRcPoV4AEAP7/ MBP/6RQgJpXhQE0ahaqU9V00l8I8lcH5ShZUukz1koK6xGzl2zrwaexs X-Gm-Gg: ASbGncs/+/WCuv7womVzPejyCM8aJrd6k5GLrQMy782/sbPIK1xBy1JXIRdlslsd+2s Y0vcbjk1fkxvmXmA2fF74wOQekngos1kBOUxh5fUn5K2t8GEjx1wgbSbyR6+znlBvNPFyA+9zAl zJQZDezbZfsmy35vCEVF1kjzHVVvYl4WlQCKhSBBqzApZaOrtcgFd59mLdCPb6pkbdxe5tgEygv 5eUSN/xcaZ878DFfuxuoxsvumW2AtWmVYXCV0BQzxCA/j+DhIpUFpoZ0DSU7fXyA3ZXTWu7oUFZ yhZ3Xs6iM1sByNhQfp/kXkKVhQVTp2OY9BvT2s7kvt/sa5PWscYQRvek/9UVEL93iWLu/lsChit /eCQM7PcbK9Bs1yXhBWoRv0PB91VER6K7R/WX X-Google-Smtp-Source: AGHT+IEf18QCG44U8jBJ4evHstdtd0oL4Hr6BpN08BPT0cHmsLXVki3gbBRZpXohq9eRx3IUTA8+0Q== X-Received: by 2002:a17:907:d2a:b0:afe:dbfb:b10e with SMTP id a640c23a62f3a-afedbfbb935mr140730666b.47.1756365531421; Thu, 28 Aug 2025 00:18:51 -0700 (PDT) Received: from localhost ([185.92.221.13]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-afe98ade972sm616427066b.50.2025.08.28.00.18.50 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 28 Aug 2025 00:18:50 -0700 (PDT) Date: Thu, 28 Aug 2025 07:18:50 +0000 From: Wei Yang To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, Zi Yan , "Mike Rapoport (Microsoft)" , SeongJae Park , 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 , 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 Subject: Re: [PATCH v1 01/36] mm: stop making SPARSEMEM_VMEMMAP user-selectable Message-ID: <20250828071850.kl7clyh6e75horlk@master> References: <20250827220141.262669-1-david@redhat.com> <20250827220141.262669-2-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250827220141.262669-2-david@redhat.com> User-Agent: NeoMutt/20170113 (1.7.2) X-Mailman-Approved-At: Fri, 29 Aug 2025 07:17:00 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Wei Yang Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, Aug 28, 2025 at 12:01:05AM +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). > >Acked-by: Zi Yan >Acked-by: Mike Rapoport (Microsoft) >Acked-by: SeongJae Park >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 Reviewed-by: Wei Yang >--- > mm/Kconfig | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > >diff --git a/mm/Kconfig b/mm/Kconfig >index 4108bcd967848..330d0e698ef96 100644 >--- a/mm/Kconfig >+++ b/mm/Kconfig >@@ -439,9 +439,8 @@ config SPARSEMEM_VMEMMAP_ENABLE > bool > > config SPARSEMEM_VMEMMAP >- bool "Sparse Memory virtual memmap" >+ def_bool y > depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE >- default y > help > SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise > pfn_to_page and page_to_pfn operations. This is the most >-- >2.50.1 > -- Wei Yang Help you, Help me