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 7E33D25CC79 for ; Sun, 19 Apr 2026 08:12:31 +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=1776586351; cv=none; b=j5ASVDuJbgavmV/Me9F1+IwnMr889Pp9aVY9pxIoq1aIxzzgaXnvxbWEw6H1GWW9XS34Anjn5I+pOvS1fk+Yr/VxJ44U3PuyqZUf8JbLHj80BaKJrUi5l4mdWFkR3194jhZpZhp86CneRBC5pQLbD1RS3ydKnF3yt8D9xg+npv4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776586351; c=relaxed/simple; bh=ig7jvjkZ1QbRCAw8nCdys/c48+Ls8Xu4gg+weYKcuIk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=eNksFNQDXuJAG06uNDMrjMY3iBLizRN/0rew1S0JfeN9x1enw0ueAT7t8EjTNmG22InJ7ElsIQizCV5ibk+OX+XCBxPJyNikviJir5gB26qkV8uPr7wfechYuYBtRqQpkJxGUw7CM3w7Yi9AtnNmbwn/GYHcaZZlatwZo9bmEqs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KF9lgz0L; 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="KF9lgz0L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5BBEC2BCAF; Sun, 19 Apr 2026 08:12:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776586351; bh=ig7jvjkZ1QbRCAw8nCdys/c48+Ls8Xu4gg+weYKcuIk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=KF9lgz0LZGMXEnJIcgltyWgzbLX4A9odPYqujzVbciAfTyZweVjXlmVQRV8J8VjFk jJW6B2mIlb/YrSeo0eKYKQFebKATSh2h0GOvPyuXrsXeKaimXRwqLJaU9CTP0EFequ Gw8/FEHQrxkPQGI7mu/4Q+fC8q0LgYcYer2WrSC/r9l7hL5hRLXWY8N4obXN234T+7 vJGo0jBx61PAjWJx8mSFMAmDm5AwlKHMG5CZ2TcenCoC4wTX5ZQaTZneEpwhtTn650 XLM50Nw/DYke8Gu6z1yFfF2Tq0CVB+r4F2sXSfXRDybq1qLjtVLkenndZoTpYI21Cn eiHE5fpKT5bMA== Message-ID: Date: Sun, 19 Apr 2026 10:12:25 +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: Cleanup up PMD Checks and warnings To: Sunny Patel Cc: akpm@linux-foundation.org, apopple@nvidia.com, byungchul@sk.com, gourry@gourry.net, joshua.hahnjy@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, matthew.brost@intel.com, rakie.kim@sk.com, sj@kernel.org, ying.huang@linux.alibaba.com, ziy@nvidia.com References: <82193ab8-e6f6-4664-8b4f-e30d280d8b1c@kernel.org> <20260418171806.11615-1-nueralspacetech@gmail.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 4/18/26 19:18, Sunny Patel wrote: > On 4/17/26 01:52, SeongJae Park wrote: >> On Thu, 16 Apr 2026 21:44:15 +0200 "David Hildenbrand (Arm)" wrote: >> >> [...] >>> >>> is_huge_zero_pmd() checks pmd_present(), so we didn't have a bug before. >>> >>> We could also do: >>> >>> if (is_huge_zero_pmd(*pmdp)) { >>> flush = true; >>> } else if (!pmd_none(*pmdp)) { >>> goto unlock_abort; >>> } >> >> Then we could even further remove the braces and reduce one more line, nice! > > is_huge_zero_pmd() didn't check for pmd_present as of now as per the current implementation of it so additional check require for pmd_present(). I don't know what you mean. Here is the code in the tree: static inline bool is_huge_zero_pmd(pmd_t pmd) { return pmd_present(pmd) && is_huge_zero_pfn(pmd_pfn(pmd)); } -- Cheers, David