[RFC PATCH 0/4] ext4: improve delalloc buffer write performance

[Zhang Yi <yi.zhang@huawei.com>]

Hi,

This patchset address to improve buffer write performance with delalloc.
The first patch reduce the unnecessary update i_disksize, the second two
patch refactor the inline data write procedure and also do some small
fix, the last patch do improve by remove all unnecessary journal handle
in the delalloc write procedure.

After this patch set, we could get a lot of performance improvement.
Below is the Unixbench comparison data test on my machine with 'Intel
Xeon Gold 5120' CPU and nvme SSD backend.

Test cmd:

  ./Run -c 56 -i 3 fstime fsbuffer fsdisk

Before this patch:

  System Benchmarks Partial Index           BASELINE       RESULT   INDEX
  File Copy 1024 bufsize 2000 maxblocks       3960.0     422965.0   1068.1
  File Copy 256 bufsize 500 maxblocks         1655.0     105077.0   634.9
  File Copy 4096 bufsize 8000 maxblocks       5800.0    1429092.0   2464.0
                                                                    ========
  System Benchmarks Index Score (Partial Only)                      1186.6

After this patch:

  System Benchmarks Partial Index           BASELINE       RESULT   INDEX
  File Copy 1024 bufsize 2000 maxblocks       3960.0     732716.0   1850.3
  File Copy 256 bufsize 500 maxblocks         1655.0     184940.0   1117.5
  File Copy 4096 bufsize 8000 maxblocks       5800.0    2427152.0   4184.7
                                                                    ========
  System Benchmarks Index Score (Partial Only)                      2053.0



Already test by fstests under below configuration, no add failure.

     delalloc  blocksize   journal  inline
1.    Y         4K          N        N
2.    Y         4K          N        Y
3.    N         4K          N        N
4.    N         4K          N        Y
5.    Y         4K          Y        N
6.    Y         4K          Y        Y
7.    Y         1K          N        N
8.    N         1K          N        N
9.    Y         1K          Y        N

Thanks,
Yi.



Zhang Yi (4):
  ext4: check and update i_disksize properly
  ext4: correct the error path of ext4_write_inline_data_end()
  ext4: factor out write end code of inline file
  ext4: drop unnecessary journal handle in delalloc write

 fs/ext4/ext4.h   |   3 --
 fs/ext4/inline.c | 124 +++++++++++++++++++++---------------------
 fs/ext4/inode.c  | 137 ++++++++++-------------------------------------
 3 files changed, 93 insertions(+), 171 deletions(-)

-- 
2.31.1