From nobody Fri Dec 19 19:14:16 2025 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 984BD25291E for ; Wed, 5 Mar 2025 18:16:22 +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=1741198582; cv=none; b=m+VNRCYf3gFvj9n8uHfpArB4Ce3nZ2FpUCFekffOOxeE1lL+rDBLgKIgQhnLQInBTn4N5wLbbL48pjNuQw5EHPfIsFEGgyW0c5UESBn3tz69NFQKaRmzp2mseTCzpDTqMkXF1b9Q7/O5wV+EQSI4F+4BwVwL7b80o28aClrNKnI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741198582; c=relaxed/simple; bh=k3u/LxEMkFkS7mrfeSjLL0Nnr2JwC5q9oxYyj2TJeAI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=qt68Ix/Jb1zX5IsPeAWOCEgDOiO9eoI4dUD9lOVzmC5QJomX0InUfaXXTZhuMGYrM3mtD5eGgdsXN3V8ulFBKsJVlvivhemkPAi7LsHd1FoiUmPF19rQvpPcBPKGzSu7hMbZ1lzO7wf3935K56PsHO5ovHhzNDwQ0eT4TT5Po9Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=d+BXnAC1; 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="d+BXnAC1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39959C4CEF2; Wed, 5 Mar 2025 18:16:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741198582; bh=k3u/LxEMkFkS7mrfeSjLL0Nnr2JwC5q9oxYyj2TJeAI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d+BXnAC1TkoainkqZ1u199F1FvvZiZ34Ndk/rNCx/M/1t+E94AGj5Quk5hqfuBfOR M1YClyfRGCUP1WoVAujO8KEYZPzAM5nyE+V9w6X04oqWzXMx1S63w8kjugzVIQPUqT vyzywq6x4ps9bDMoX5nQ0n4xouj/atCwPePYKOQDZ9OKJUcyAhG1rAbQvIxrVUDWuc fUV1pP5jvKW6nsjwv7a+fJk5BM7bKW+1NdufBwSEcLDO2AH5PRhrJ8rKbQOMJzAtor VkesKLWj63wstq8GYdHeUtU7YoUmatCsQXyNU7EPPvlIriyjFwml6cKma9iQLIPNg/ DVjdb/F+G4fYA== From: SeongJae Park To: Cc: SeongJae Park , "Liam R. Howlett" , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Shakeel Butt , Vlastimil Babka , kernel-team@meta.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH 02/16] mm/madvise: split out populate behavior check logic Date: Wed, 5 Mar 2025 10:15:57 -0800 Message-Id: <20250305181611.54484-3-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250305181611.54484-1-sj@kernel.org> References: <20250305181611.54484-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" madvise_do_behavior() has a long open-coded 'behavior' check for MADV_POPULATE_{READ,WRITE}. It adds multiple layers[1] and make the code arguably take longer time to read. Like is_memory_failure(), split out the check to a separate function. This is not technically removing the additional layer but discourage further extending the switch-case. Also it makes madvise_do_behavior() code shorter and therefore easier to read. [1] https://lore.kernel.org/bd6d0bf1-c79e-46bd-a810-9791efb9ad73@lucifer.lo= cal Signed-off-by: SeongJae Park --- mm/madvise.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index dbc8fec05cc6..4a91590656dc 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1633,6 +1633,17 @@ static bool is_valid_madvise(unsigned long start, si= ze_t len_in, int behavior) return true; } =20 +static bool is_memory_populate(int behavior) +{ + switch (behavior) { + case MADV_POPULATE_READ: + case MADV_POPULATE_WRITE: + return true; + default: + return false; + } +} + static int madvise_do_behavior(struct mm_struct *mm, unsigned long start, size_t len_in, size_t len, int behavior) { @@ -1646,16 +1657,11 @@ static int madvise_do_behavior(struct mm_struct *mm, end =3D start + len; =20 blk_start_plug(&plug); - switch (behavior) { - case MADV_POPULATE_READ: - case MADV_POPULATE_WRITE: + if (is_memory_populate(behavior)) error =3D madvise_populate(mm, start, end, behavior); - break; - default: + else error =3D madvise_walk_vmas(mm, start, end, behavior, madvise_vma_behavior); - break; - } blk_finish_plug(&plug); return error; } --=20 2.39.5