From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 42CC74418F2 for ; Thu, 27 Aug 2026 11:08:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787828913; cv=none; b=L+TyseNX5rjAJguktr4VObWhew1Q3t3C+vluTK4dVUVXDFA014vINhGinjY2V0A8dBsc1e6CwPoA31qO0Two8m3Uf+RyCgspRuXrceQ3xAH1iotLl9nJMEj0Crxap+DiSDRkjR6Lnz4fkAvf1sRpleNR5ldCy7Dg+SicG1drxf0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787828913; c=relaxed/simple; bh=5ZykGnMPOhvzMIA2h9GZFruy1aASyXjtb5HZuu8hA1E=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=NzCNVB6pj7J3znSt445ooZ2fwYbqJ2kFX9IbzQ9KVBKFevhX3CZjI8knZ0j+NsFIZkJp12xicwoYjMrAuX47yOoKY72l6N9rsOA35uuAvBzzvzD8ZJsUlhMGNJiXq78Cbi4OPDFhEgYv78icxS7oHmYXoKlqIUvlBdd/fjIkbdE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Q/cKQ6g/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Q/cKQ6g/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 821A61F000E9; Thu, 27 Aug 2026 11:08:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787828910; bh=1x0zBWdMtgqZiQur8SMfQr/RwwtWwQSC5GfZhLiryLQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=Q/cKQ6g/TLt2dqqMpsGuq4/xHZqR0cRp812aS7hA6QfuKfmqgPUfUEGoaLLYDZZSP Mnwc9dN0Fa4TBFOATCyM5pjkeuce0Ze+S5aZwmujhkdFGXeY0sVALZBN/qsnxUC6U7 KIsJCoTQrzzE1GLC/6MtPhl2YgjQqcIlWKWsUQdfucgVgLS2JDA9Q9LXNDNs9BzCqC oYvSwn3BKOaIrBbwftXxpOfNhz1n0pJNLtDOkDPGuYHtFc1KaopfCiw8UtG7ernwwz y8BdEGIWDRT7DkM0z3vpvaLrmHg1lgcJdOfb4vuxdkud813Qa1MaFqyL9GgP0N3UPQ KZWhg2/Ca3zcQ== Message-ID: <21329b69-1a58-4b3e-918b-26753a961339@kernel.org> Date: Thu, 27 Aug 2026 13:08:24 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] riscv: mm: Flush vmemmap TLB after sparse_init() To: Yaxing Guo , Paul Walmsley , Mike Rapoport Cc: Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Andrew Morton , Lorenzo Stoakes , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Zhizun Wang References: <20260827073603.141426-1-guoyaxing@bosc.ac.cn> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/27/26 09:36, Yaxing Guo wrote: > Commit 4267739cabb8 ("arch, mm: consolidate initialization of SPARSE > memory model") moved sparse_init() from RISC-V arch setup code into > free_area_init(), but left the RISC-V VMEMMAP TLB flush in > misc_mem_init(). RISC-V now flushes the VMEMMAP range before > sparse_init() populates the vmemmap page tables. > > RISC-V supports caching non-present entries in the TLB. If a hart cached > a non-present translation for the VMEMMAP range, installing the vmemmap > page-table entries is not guaranteed to be observed until an sfence.vma > invalidates the stale entry. The first access to the corresponding > struct page during memmap initialization can then hit the old non-present > entry. > > Call an arch hook at the end of sparse_init(), after the boot-time > vmemmap population has completed. If it's a vmemmap thing, it should go into the vmemmap machinery, not slapped into sparse.c. Why can't the proposed vmemmap_populate_finalize() [1] cleanly take care of that? [1] https://lore.kernel.org/linux-riscv/20260630-mark-after-vmemmap-populate-v4-1-febbc15da028@iscas.ac.cn/ (independent of that, I really don't enjoy the suggested callback name) -- Cheers, David