Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934631Ab2FIAwV (ORCPT ); Fri, 8 Jun 2012 20:52:21 -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 S934539Ab2FIAvZ (ORCPT ); Fri, 8 Jun 2012 20:51:25 -0400 From: Akinobu Mita To: linux-kernel@vger.kernel.org, akpm@linux-foundation.org Cc: Akinobu Mita , Jan Kara , Andreas Dilger , linux-ext4@vger.kernel.org Subject: [PATCH v3 8/9] ext3: use memweight() Date: Sat, 9 Jun 2012 09:50:37 +0900 Message-Id: <1339203038-13069-8-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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2496 Lines: 75 Convert ext3_count_free() to use memweight() instead of table lookup based counting clear bits implementation. This change only affects the code segments enabled by EXT3FS_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 ext3_count_free() which always takes non-null pointer as the memory area. - Fix printk format warning that only reveals with EXT3FS_DEBUG. Signed-off-by: Akinobu Mita Cc: Jan Kara Cc: Andrew Morton Cc: Andreas Dilger Cc: linux-ext4@vger.kernel.org --- v3: rewrite to keep ext3_count_free() as a wrapper for memweight() fs/ext3/balloc.c | 2 +- fs/ext3/bitmap.c | 12 +----------- 2 files changed, 2 insertions(+), 12 deletions(-) diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c index 25cd608..90d901f 100644 --- a/fs/ext3/balloc.c +++ b/fs/ext3/balloc.c @@ -1813,7 +1813,7 @@ ext3_fsblk_t ext3_count_free_blocks(struct super_block *sb) brelse(bitmap_bh); printk("ext3_count_free_blocks: stored = "E3FSBLK ", computed = "E3FSBLK", "E3FSBLK"\n", - le32_to_cpu(es->s_free_blocks_count), + (ext3_fsblk_t)le32_to_cpu(es->s_free_blocks_count), desc_count, bitmap_count); return bitmap_count; #else diff --git a/fs/ext3/bitmap.c b/fs/ext3/bitmap.c index 909d13e..ef9c643 100644 --- a/fs/ext3/bitmap.c +++ b/fs/ext3/bitmap.c @@ -11,19 +11,9 @@ #ifdef EXT3FS_DEBUG -static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0}; - unsigned long ext3_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 /* EXT3FS_DEBUG */ -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/