Can you try this patch ? commit 6a910bd1d28be09ba3a0e073bae78285ce057a5f Author: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Date: Tue Jun 9 01:38:53 2009 +0530 ext4: Use different normalization method for allocation size. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index ed8482e..7f2423b 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -633,7 +633,7 @@ static void ext4_mb_mark_free_simple(struct super_block *sb, BUG_ON(len > EXT4_BLOCKS_PER_GROUP(sb)); - border = 2 << sb->s_blocksize_bits; + border = 1 << (sb->s_blocksize_bits + 1); while (len > 0) { /* find how many blocks can be covered since this position */ @@ -3063,8 +3063,10 @@ static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac) ext4_mb_normalize_request(struct ext4_allocation_context *ac, struct ext4_allocation_request *ar) { - int bsbits, max; + int bsbits, i; + loff_t max; ext4_lblk_t end; + unsigned int s_mb_stream_request; loff_t size, orig_size, start_off; ext4_lblk_t start, orig_start; struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); @@ -3090,54 +3092,52 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac, } bsbits = ac->ac_sb->s_blocksize_bits; + s_mb_stream_request = EXT4_SB(ac->ac_sb)->s_mb_stream_request; + /* make sure this is power of 2 */ + s_mb_stream_request = + roundup_pow_of_two((unsigned long)s_mb_stream_request); /* first, let's learn actual file size * given current request is allocated */ size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len; - size = size << bsbits; - if (size < i_size_read(ac->ac_inode)) - size = i_size_read(ac->ac_inode); - - /* max size of free chunks */ - max = 2 << bsbits; + if (size < (i_size_read(ac->ac_inode) >> bsbits)) + size = i_size_read(ac->ac_inode) >> bsbits; + /* + * max free chunk blocks. + * (max buddy cache order is (bsbits + 1). + */ + max = 1 << (bsbits + 1); #define NRL_CHECK_SIZE(req, size, max, chunk_size) \ - (req <= (size) || max <= (chunk_size)) + (((req <= (size)) && (req <= (chunk_size))) || max <= (chunk_size)) /* first, try to predict filesize */ /* XXX: should this table be tunable? */ start_off = 0; - if (size <= 16 * 1024) { - size = 16 * 1024; - } else if (size <= 32 * 1024) { - size = 32 * 1024; - } else if (size <= 64 * 1024) { - size = 64 * 1024; - } else if (size <= 128 * 1024) { - size = 128 * 1024; - } else if (size <= 256 * 1024) { - size = 256 * 1024; - } else if (size <= 512 * 1024) { - size = 512 * 1024; - } else if (size <= 1024 * 1024) { - size = 1024 * 1024; - } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) { - start_off = ((loff_t)ac->ac_o_ex.fe_logical >> - (21 - bsbits)) << 21; - size = 2 * 1024 * 1024; - } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) { - start_off = ((loff_t)ac->ac_o_ex.fe_logical >> - (22 - bsbits)) << 22; - size = 4 * 1024 * 1024; - } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len, - (8<<20)>>bsbits, max, 8 * 1024)) { - start_off = ((loff_t)ac->ac_o_ex.fe_logical >> - (23 - bsbits)) << 23; - size = 8 * 1024 * 1024; - } else { - start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits; - size = ac->ac_o_ex.fe_len << bsbits; + + /* + * less than s_mb_stream_request is using locality group + * preallocation + */ + if (size <= s_mb_stream_request) + size = s_mb_stream_request; + i = 4; + while (1) { + /* + * if (size <= 4 * s_mb_stream || + * max <= 2 * s_mb_stream ) size = 2 * s_mb_stream + */ + if (NRL_CHECK_SIZE(size, i * s_mb_stream_request, + max, ((i * s_mb_stream_request) >> 1))) { + /* number of blocks */ + size = (i * s_mb_stream_request) >> 1; + size = size << bsbits; + start_off = (loff_t)ac->ac_o_ex.fe_logical & ~(size - 1); + break; + } + i = i << 1; } + orig_size = size = size >> bsbits; orig_start = start = start_off >> bsbits; -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html