From patchwork Sat Jun 9 00:50:36 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Akinobu Mita X-Patchwork-Id: 163876 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 5822BB6F86 for ; Sat, 9 Jun 2012 10:52:28 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932668Ab2FIAvv (ORCPT ); Fri, 8 Jun 2012 20:51:51 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:59124 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934538Ab2FIAvU (ORCPT ); Fri, 8 Jun 2012 20:51:20 -0400 Received: by mail-pz0-f46.google.com with SMTP id y13so3005695dad.19 for ; Fri, 08 Jun 2012 17:51:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=10qk9BoIRmx0c0yC3URpOUyezQxxu3/B7bYh7f6hniY=; b=RbJ7WJD97E7mrXfKgn7ECdLads3GgHTRNTAjZmbEEkbgnXDLMKYzZ3Ya5UUK7qTSD2 OXsT0tDnw2RLypfIUxsDbFQxOWFU5KFVIkH0VWtZmZh//4A6N+9aB4AHVf9PpZwd9ITk kLhd3SA1xw0bxnCHo2dt2u9fAYjWh/34AbNwYLRZIIENFUY8QcDBvtyUoSoF5Oz46MhB pbA2wI9qVF91CM0QKoBAskdzS3NSasqPW5IfuIxrw7uy0QqMzaEsR/sCijOLXFk7OmOF s+HAJ86CaIQX4Iaa0zl5ZSHrkGAQVArkJD7YCgrWgMsYAv164lVy0iAA3awOfYRZnkcp J3YA== Received: by 10.68.237.166 with SMTP id vd6mr524510pbc.139.1339203079861; Fri, 08 Jun 2012 17:51:19 -0700 (PDT) Received: from localhost.localdomain (p15023-ipngn1901hodogaya.kanagawa.ocn.ne.jp. [180.11.8.23]) by mx.google.com with ESMTPS id hc7sm9536241pbc.54.2012.06.08.17.51.15 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 08 Jun 2012 17:51:18 -0700 (PDT) From: Akinobu Mita To: linux-kernel@vger.kernel.org, akpm@linux-foundation.org Cc: Akinobu Mita , Jan Kara , linux-ext4@vger.kernel.org Subject: [PATCH v3 7/9] ext2: use memweight() Date: Sat, 9 Jun 2012 09:50:36 +0900 Message-Id: <1339203038-13069-7-git-send-email-akinobu.mita@gmail.com> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1339203038-13069-1-git-send-email-akinobu.mita@gmail.com> References: <1339203038-13069-1-git-send-email-akinobu.mita@gmail.com> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Convert ext2_count_free() to use memweight() instead of table lookup based counting clear bits implementation. This change only affects the code segments enabled by EXT2FS_DEBUG. Note that this memweight() call can't be replaced with a single bitmap_weight() call, although the pointer to the memory area is aligned to long-word boundary. Because the size of the memory area may not be a multiple of BITS_PER_LONG, then it returns wrong value on big-endian architecture. This also includes the following changes. - Remove unnecessary map == NULL check in ext2_count_free() which always takes non-null pointer as the memory area. - Fix printk format warning that only reveals with EXT2FS_DEBUG. Signed-off-by: Akinobu Mita Cc: Jan Kara Cc: linux-ext4@vger.kernel.org --- v3: rewrite to keep ext2_count_free() as a wrapper for memweight() fs/ext2/balloc.c | 14 ++------------ fs/ext2/ialloc.c | 1 + 2 files changed, 3 insertions(+), 12 deletions(-) diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index 1c36139..376aa77 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -1444,19 +1444,9 @@ ext2_fsblk_t ext2_new_block(struct inode *inode, unsigned long goal, int *errp) #ifdef EXT2FS_DEBUG -static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0}; - -unsigned long ext2_count_free (struct buffer_head * map, unsigned int numchars) +unsigned long ext2_count_free(struct buffer_head *map, unsigned int numchars) { - unsigned int i; - unsigned long sum = 0; - - if (!map) - return (0); - for (i = 0; i < numchars; i++) - sum += nibblemap[map->b_data[i] & 0xf] + - nibblemap[(map->b_data[i] >> 4) & 0xf]; - return (sum); + return numchars * BITS_PER_BYTE - memweight(map->b_data, numchars); } #endif /* EXT2FS_DEBUG */ diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c index c13eb7b..8f370e01 100644 --- a/fs/ext2/ialloc.c +++ b/fs/ext2/ialloc.c @@ -644,6 +644,7 @@ unsigned long ext2_count_free_inodes (struct super_block * sb) } brelse(bitmap_bh); printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n", + (unsigned long) percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter), desc_count, bitmap_count); return desc_count;