From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48DCBC43457 for ; Fri, 16 Oct 2020 03:56:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0EF072074F for ; Fri, 16 Oct 2020 03:56:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="V0roP42R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394325AbgJPD4I (ORCPT ); Thu, 15 Oct 2020 23:56:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394317AbgJPD4F (ORCPT ); Thu, 15 Oct 2020 23:56:05 -0400 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 62249C061755 for ; Thu, 15 Oct 2020 20:56:05 -0700 (PDT) Received: by mail-pf1-x444.google.com with SMTP id j18so716516pfa.0 for ; Thu, 15 Oct 2020 20:56:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=yXU/MqBPj3mvgTMYLaZ63PpolhXc6mLjM3ETWa5F6N0=; b=V0roP42REy3e9hwHDMWRnUlwtHuH8BwRi2OuAu0wPo8uOGyddK4m7dOewgGa4UeUXI c77VIfBa2Xs+l8eG0ax4N6cvRgDdgmnqxRanNW1G/TlqDWGkGqaSQsbmizUVlpUHoYko kVNlbe4B75xUyKjBWR53CNq6v3uEdtDb8N0nFEDB3+DCZMfSYl0FdZzbDldHHqMgACO7 eHv/nkU1PkxMpT8uhV5n3fhPIfCg5qoYarCuSk/O4eUcg6nnubqOL2YS1QnzKXSgQTSr VM2oTL3yxBhTis2/ZTlRL/JMMKlLN1ajB46F+C7TjzCX1itqzO2zxtPEHGVCYlQuWpzx 3Vaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=yXU/MqBPj3mvgTMYLaZ63PpolhXc6mLjM3ETWa5F6N0=; b=ModO05dykAADMqBGS73efTV81GbBymnK6/IayzC5Jzsg/40J71E00OOqhX4Ni/t9Yu BEmMEscTb1z8JpKV34K+F4BZpZcrlgqgFKO7UUHG52pHqldQTYgsiH7PydYR4fQWnv2y BPDFQY5PC9cBg7z8osddVR/SrhM9TCkIlpPdNYbL1wPh95kKj0mpW5hXv/Y0UXBK2vRE nHOefmcA7lzFf0bGOqMnhPk6+6iuW3kvukxACV47dhZOed6v6vCxa1xvZTT+YoAbPrL9 cIVG9ngTzOuNTmbCcRGTW6CP693KeE5ZUjFy8quAMiAm02UOPBUihWKxUrIZpIJQFiMQ qcxg== X-Gm-Message-State: AOAM532Y7NqieJ9EfQL3YOb8TgsT/SwuddAGxrizHFBai0OHhLPbtsOy ht11ZbXaSmcImaVZz4acIZ8= X-Google-Smtp-Source: ABdhPJw5ilKfd33RNpNIbn6jGqO3gDnhs7q6EfziOzb2WQtqxPSikQCd7T6NDC3REyFs9N3OxgdM8A== X-Received: by 2002:a63:1c4e:: with SMTP id c14mr1461260pgm.98.1602820564952; Thu, 15 Oct 2020 20:56:04 -0700 (PDT) Received: from VM-0-6-centos.localdomain ([119.28.90.140]) by smtp.gmail.com with ESMTPSA id v12sm861555pgr.4.2020.10.15.20.56.03 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 15 Oct 2020 20:56:04 -0700 (PDT) From: Chunguang Xu X-Google-Original-From: Chunguang Xu To: tytso@mit.edu, adilger.kernel@dilger.ca Cc: linux-ext4@vger.kernel.org Subject: [PATCH 4/8] ext4: simplify the code of mb_find_order_for_block Date: Fri, 16 Oct 2020 11:55:48 +0800 Message-Id: <1602820552-4082-4-git-send-email-brookxu@tencent.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1602820552-4082-1-git-send-email-brookxu@tencent.com> References: <1602820552-4082-1-git-send-email-brookxu@tencent.com> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Chunguang Xu The code of mb_find_order_for_block is a bit obscure, but we can simplify it with mb_find_buddy(), make the code more concise. Signed-off-by: Chunguang Xu --- fs/ext4/mballoc.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 5b8ce76..2eead37 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1289,22 +1289,18 @@ static void ext4_mb_unload_buddy(struct ext4_buddy *e4b) static int mb_find_order_for_block(struct ext4_buddy *e4b, int block) { - int order = 1; - int bb_incr = 1 << (e4b->bd_blkbits - 1); + int order = 1, max; void *bb; BUG_ON(e4b->bd_bitmap == e4b->bd_buddy); BUG_ON(block >= (1 << (e4b->bd_blkbits + 3))); - bb = e4b->bd_buddy; while (order <= e4b->bd_blkbits + 1) { - block = block >> 1; - if (!mb_test_bit(block, bb)) { + bb = mb_find_buddy(e4b, order, &max); + if (!mb_test_bit(block >> order, bb)) { /* this block is part of buddy of order 'order' */ return order; } - bb += bb_incr; - bb_incr >>= 1; order++; } return 0; -- 1.8.3.1