Re: [PATCH 0/3] Create large folios in iomap buffered write path

[Wang Yugui <wangyugui@e16-tech.com>]

Hi,

> Wang Yugui has a workload which would be improved by using large folios.
> Until now, we've only created large folios in the readahead path,
> but this workload writes without reading.  The decision of what size
> folio to create is based purely on the size of the write() call (unlike
> readahead where we keep history and can choose to create larger folios
> based on that history even if individual reads are small).
> 
> The third patch looks like it's an optional extra but is actually needed
> for the first two patches to work in the write path, otherwise it limits
> the length that iomap_get_folio() sees to PAGE_SIZE.

very good test result on 6.4.0-rc2. 
# just drop ';' in 'if (bytes > folio_size(folio) - offset);' of [PATCH 3/3].

fio -name write-bandwidth -rw=write -bs=1024Ki -size=32Gi -runtime=30 -iodepth 1
-ioengine sync -zero_buffers=1 -direct=0 -end_fsync=1 -numjobs=4
-directory=/mnt/test
fio WRITE: bw=7655MiB/s (8027MB/s).

Now it is the same as 5.15.y

Best Regards
Wang Yugui (wangyugui@e16-tech.com)
2023/05/21


> Matthew Wilcox (Oracle) (3):
>   filemap: Allow __filemap_get_folio to allocate large folios
>   iomap: Create large folios in the buffered write path
>   iomap: Copy larger chunks from userspace
> 
>  fs/gfs2/bmap.c          |  2 +-
>  fs/iomap/buffered-io.c  | 32 ++++++++++++++++++------------
>  include/linux/iomap.h   |  2 +-
>  include/linux/pagemap.h | 29 ++++++++++++++++++++++++---
>  mm/filemap.c            | 44 ++++++++++++++++++++++++++++-------------
>  mm/folio-compat.c       |  2 +-
>  mm/readahead.c          | 13 ------------
>  7 files changed, 78 insertions(+), 46 deletions(-)
> 
> -- 
> 2.39.2