From 20acaa18d0c002fec180956f87adeb3f11f635a6 Mon Sep 17 00:00:00 2001 From: Suparna Bhattacharya <suparna@in.ibm.com> Date: Sat, 16 Sep 2006 12:15:58 -0700 Subject: [PATCH] [PATCH] ext3 sequential read regression fix 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 <suparna@in.ibm.com> Tested-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> --- fs/ext3/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index 0f0b1eadb98d..84be02e93652 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -925,7 +925,7 @@ int ext3_get_blocks_handle(handle_t *handle, struct inode *inode, 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 */ -- GitLab