From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9841A165F16 for ; Thu, 19 Mar 2026 17:16:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773940566; cv=none; b=o0F5TdzpVZZt4XJsCNhP9dlvf1gYrYunOOR7QpQBJriZGWIOsu5hJLYETAVl0xnEzFRgWHHwkARoVwGCqoewTU86C5SI8cjC+DdcO8IRcyqaFlUzLS5m5JrFuubrf0qdbJA+VaNHjlFWXwJCnz4NrY2U75FhrXNjVY031ti2B6Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773940566; c=relaxed/simple; bh=kddz7Lr4KV800cJ5ixeD7N4MIGzmX7aClz+fV4i7T+I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=IK7jr83Hlu31QVvYsHQ7nNe/SCBJpNYEttQoJHhhgFGUA/4bblXtv+m0nBe4j1yfVSDMkQVb6JWtbOvWjrOu8t8N+u6KX5HePDvxQJZuRmBAis19cv2gCvwEf3rAdV6EBlpeW4aKVDw4RQ7JzHHCB1fmJQneFrHXntDxmswzT2g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HW19/v6y; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HW19/v6y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B266C19424; Thu, 19 Mar 2026 17:16:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773940566; bh=kddz7Lr4KV800cJ5ixeD7N4MIGzmX7aClz+fV4i7T+I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HW19/v6ypMVaXRu8g6Dai96+eN+7cHup6p6AKDjpoUtyc6dWHd5A5/93LVEpALWkr QvEbbyXKp1v+8GpCtH3FDJJhBH5INDh3o85CMilGM0Lof/ZxhYuLy2j0o18XXXAqAM jsldXmKEEwZDAV9Rpfoukzab8sIXV7BtNtGGNxfPr1lQfFRh2I8W9jks0ClorshK17 RUxF76pfNaHJdu4tbdl2x73dBFRwm2MxpFuQ1coaI5ItgLgiFtQMtoo/fBAn6CN6SZ 1JeruWtlbDQqOfbNU82bx88iNRV7FwYvvOvAmuudnNivMqJvaNzXYf7PNbcl69ci4G kif5qhb2U4l8w== Date: Thu, 19 Mar 2026 17:16:00 +0000 From: "Lorenzo Stoakes (Oracle)" To: Kiryl Shutsemau Cc: Andrew Morton , David Hildenbrand , Zi Yan , Baolin Wang , "Liam R . Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/9] mm/huge_memory: simplify vma_is_specal_huge() Message-ID: <4eb64482-1a9e-4797-ba59-9dd3551189ee@lucifer.local> References: <613669b1b2082d34f5632907003ae3874eff2ed9.1773924928.git.ljs@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Mar 19, 2026 at 04:52:31PM +0000, Kiryl Shutsemau wrote: > On Thu, Mar 19, 2026 at 01:00:07PM +0000, Lorenzo Stoakes (Oracle) wrote: > > This function is confused - it overloads the term 'special' yet again, > > checks for DAX but in many cases the code explicitly excludes DAX before > > invoking the predicate. > > > > It also unnecessarily checks for vma->vm_file - this has to be present for > > a driver to have set VMA_MIXEDMAP_BIT or VMA_PFNMAP_BIT. > > What enforces this? f_op->mmap() or ->mmap_prepare() would have to have been called for these to be set, requiring a file to have file operations to be able to do so. > > -- > Kiryl Shutsemau / Kirill A. Shutemov