[PATCH] ext3 sequential read regression fix

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



ext3-get-blocks support caused ~20% degrade in Sequential read
performance (tiobench). Problem is with marking the buffer boundary
so IO can be submitted right away. Here is the patch to fix it.

2.6.18-rc6:
-----------
# ./iotest
1048576+0 records in
1048576+0 records out
4294967296 bytes (4.3 GB) copied, 75.2726 seconds, 57.1 MB/s

real    1m15.285s
user    0m0.276s
sys     0m3.884s


2.6.18-rc6 + fix:
-----------------
[root@elm3a241 ~]# ./iotest
1048576+0 records in
1048576+0 records out
4294967296 bytes (4.3 GB) copied, 62.9356 seconds, 68.2 MB/s


The boundary block check in ext3_get_blocks_handle needs to be adjusted
against the count of blocks mapped in this call, now that it can map
more than one block.

Signed-off-by: Suparna Bhattacharya <[email protected]>
Tested-by: Badari Pulavarty <[email protected]>

 linux-2.6.18-rc5-suparna/fs/ext3/inode.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)

diff -puN fs/ext3/inode.c~ext3-multiblock-boundary-fix fs/ext3/inode.c
--- linux-2.6.18-rc5/fs/ext3/inode.c~ext3-multiblock-boundary-fix	2006-09-15 10:53:12.000000000 +0530
+++ linux-2.6.18-rc5-suparna/fs/ext3/inode.c	2006-09-15 10:54:30.000000000 +0530
@@ -925,7 +925,7 @@ int ext3_get_blocks_handle(handle_t *han
 	set_buffer_new(bh_result);
 got_it:
 	map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
-	if (blocks_to_boundary == 0)
+	if (count > blocks_to_boundary)
 		set_buffer_boundary(bh_result);
 	err = count;
 	/* Clean up and exit */



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux