Commit 20acaa18d0c002fec180956f87adeb3f11f635a6
Committed by
Linus Torvalds
1 parent
e4b69aa2a1
Exists in
master
and in
7 other branches
[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>
Showing 1 changed file with 1 additions and 1 deletions Side-by-side Diff
fs/ext3/inode.c
... | ... | @@ -925,7 +925,7 @@ |
925 | 925 | set_buffer_new(bh_result); |
926 | 926 | got_it: |
927 | 927 | map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); |
928 | - if (blocks_to_boundary == 0) | |
928 | + if (count > blocks_to_boundary) | |
929 | 929 | set_buffer_boundary(bh_result); |
930 | 930 | err = count; |
931 | 931 | /* Clean up and exit */ |