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 844CE3451C6 for ; Mon, 17 Aug 2026 17:47:58 +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=1786988881; cv=none; b=jW03Ccd4b2NLzY/rtVbFrinvClX/9vZxxiK6m3wXlc+sq5x8JqgSiM7x269G5flUS5FvdeJIKsCyle1/+J1kHB3rN7fmlpxHp8pkWRVZHh9/K0r+JkJbxghvh6VbEPRkO6J7c2eIcfcr5IRkehtrjlwP5yUUCqLApnN1xDvRbdE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786988881; c=relaxed/simple; bh=ko0zDnahKo1ldAKTXjx3XwSna02z3NsAHfZz1ONA2XI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=JzfWLZLKr3IuaeCEdqYLvjCWmK5CiQF+G0WP1Rngdyff+MZCnXYaQP4hYCtl2v3yyALgWYoA9OOD3G7rFsJlGT2ZXM11SnxlfmTQL/+LvLxMF/UPZDf8vTwNbVV2In24A/Iwv9kgsTVVhkhqZq6Daw6kHWIXKcEo4oeNoWTAEO8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UFC53VTl; 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="UFC53VTl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E09A61F000E9; Mon, 17 Aug 2026 17:47:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786988878; bh=iOfZaB713Ys+B7W6jfvJNm+JxoikF1oqkGAtPEWVmKM=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=UFC53VTl2Puis5UdHizYJS6wpzdkR0Y4Cs2swJC+qyXyAJgM1ZYkvox7UjN5rhbsj 1+NFH13oX6N+hcodMHyEgtNPdNRlwoqSt98ZPNHZKtNyDp6PXseAXNVN9Ls0qdFCG5 oGf1yvZ9jgHFPR0lBXgqHL8/3mqgAwmgBfdPPGzGXRMq6ateng8F+4B3n3WzVi2QRH ZtfVbyZSB3L8fcXmbNE+QHMT7xtuyH5E8YwbOyVCqbg/mNHEtJA+AzZwPkRCb0y2rA 8KMB33y59JwnRcapyXIzk1JimaAEJ8E6iTxCL3h7twR3XZJQzQYsHPeG1IYmMKeS/H myNzcFZeLvwpw== Message-ID: <4148c151-5ef7-4e5e-986e-b05e600045db@kernel.org> Date: Mon, 17 Aug 2026 19:47:51 +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] mm/migrate_device: fix cache flush when replacing huge zero PMD To: Zi Yan , Hui Su , Andrew Morton Cc: Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Balbir Singh , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260817060845.377800-2-sh_def@163.com> 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 8/17/26 18:39, Zi Yan wrote: > On Mon Aug 17, 2026 at 2:08 AM EDT, Hui Su wrote: >> migrate_vma_insert_huge_pmd_page() calls flush_cache_page() before >> replacing an existing huge zero PMD. However, the third argument to >> flush_cache_page() is a PFN, while addr + HPAGE_PMD_SIZE is an end >> virtual address. >> >> More importantly, the mapping being invalidated is PMD-sized rather >> than PAGE_SIZE-sized. Flush the whole PMD range with >> flush_cache_range(), matching other huge PMD invalidation paths. >> >> Fixes: a30b48bf1b24 ("mm/migrate_device: implement THP migration of zone device pages") >> Signed-off-by: Hui Su >> --- >> mm/migrate_device.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> > > Thank you for fixing it. > > Reviewed-by: Zi Yan Acked-by: David Hildenbrand (Arm) I do wonder whether there should be a PMD helper. -- Cheers, David