From nobody Mon Sep 15 01:58:49 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92ACEC54EBE for ; Tue, 17 Jan 2023 02:11:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235270AbjAQCLJ (ORCPT ); Mon, 16 Jan 2023 21:11:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235097AbjAQCLA (ORCPT ); Mon, 16 Jan 2023 21:11:00 -0500 Received: from mail-oa1-x34.google.com (mail-oa1-x34.google.com [IPv6:2001:4860:4864:20::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B36701F5F7 for ; Mon, 16 Jan 2023 18:10:59 -0800 (PST) Received: by mail-oa1-x34.google.com with SMTP id 586e51a60fabf-15027746720so30592253fac.13 for ; Mon, 16 Jan 2023 18:10:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=student.cerritos.edu; s=google; h=cc:to:subject:message-id:date:from:mime-version:from:to:cc:subject :date:message-id:reply-to; bh=0OQq6sgsmukTPLDtsi9sQirhnS6juHbF/KtUXWbWsQw=; b=UE+D5RBHuqgPxFaUfvL0pMCO2VdpmpiH/iGxIY6bhROO7PC0m4Qz+qhO9z1xctMzbS c/wJZdNcCgNreZ/bCC0U5LdfkroOieXOh21UBP8W2AgdZlH673u9W6/UBb7YTYJkMEA9 MouajhwfTa+yAyVBNF4TnqqxNxeAXZ2wwA/70= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=0OQq6sgsmukTPLDtsi9sQirhnS6juHbF/KtUXWbWsQw=; b=gcgMrhqYrxg745X2fbyBBuDTmrK4daZ00wh5vk+DXd8a840oicEJLY0Mcg1h/UHn/F tu9tCp45TYG8B2uh5cpzvcJ1rBmK0Wyay5HHjrfjVzwxXJbK77seqYBt24DtU6V4zrCX PGc9HGciLWrRRqE4wD+HApDzojdfBnKMP/wPSRv4DJcLJoNz7hI/BSg4kKQFsRk8RZM7 6hkbmmnmKMKIlF1Ml8221bjKNVaWiLhqc1EMWulzjpo+30xZiWe9qyADa5GHVrVhNJWJ qsw2oEstdPzxVTOreg6YQm3BVAUrQ+J/uL4e80ctMp2YnlIoHdEUpH62UKKiw+/sNWwG LfKw== X-Gm-Message-State: AFqh2krDC0TvCOdjpZH8bxdwFcBfGxd2V+i3AqwkQ5iyeRfDYPl3+eAM z/1NlUbQ51h1GU66gzrPnC/7c/tS/NFBrSroUZQYfA== X-Google-Smtp-Source: AMrXdXs/GIZ2QFT/lL5r3nXrYUYMPp3XALm9kB4VA9t1YRxoA3vWiyPbll+Kw4SBtelCDAotyTHNjc12EdyeKEqOlhs= X-Received: by 2002:a05:6870:4949:b0:144:8d99:ef86 with SMTP id fl9-20020a056870494900b001448d99ef86mr152873oab.254.1673921459055; Mon, 16 Jan 2023 18:10:59 -0800 (PST) MIME-Version: 1.0 From: Amy Parker Date: Mon, 16 Jan 2023 18:11:00 -0800 Message-ID: Subject: [PATCH] dax: use switch statement over chained ifs To: willy@infradead.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This patch uses a switch statement for pe_order, which improves readability and on some platforms may minorly improve performance. It also, to improve readability, recognizes that `PAGE_SHIFT - PAGE_SHIFT' is a constant, and uses 0 in its place instead. Signed-off-by: Amy Parker --- fs/dax.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index c48a3a93ab29..e8beed601384 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -32,13 +32,16 @@ static inline unsigned int pe_order(enum page_entry_size pe_size) { - if (pe_size =3D=3D PE_SIZE_PTE) - return PAGE_SHIFT - PAGE_SHIFT; - if (pe_size =3D=3D PE_SIZE_PMD) + switch (pe_size) { + case PE_SIZE_PTE: + return 0; + case PE_SIZE_PMD: return PMD_SHIFT - PAGE_SHIFT; - if (pe_size =3D=3D PE_SIZE_PUD) + case PE_SIZE_PUD: return PUD_SHIFT - PAGE_SHIFT; - return ~0; + default: + return ~0; + } } /* We choose 4096 entries - same as per-zone page wait tables */ --=20 2.39.0