Re: [PATCH v5 2/2] f2fs: add ckpt_valid_blocks to the section entry

[Chao Yu <chao@kernel.org>]

On 5/12/25 15:36, yohan.joung wrote:
> when performing buffered writes in a large section,
> overhead is incurred due to the iteration through
> ckpt_valid_blocks within the section.
> when SEGS_PER_SEC is 128, this overhead accounts for 20% within
> the f2fs_write_single_data_page routine.
> as the size of the section increases, the overhead also grows.
> to handle this problem ckpt_valid_blocks is
> added within the section entries.
> 
> Test
> insmod null_blk.ko nr_devices=1 completion_nsec=1  submit_queues=8
> hw_queue_depth=64 max_sectors=512 bs=4096 memory_backed=1
> make_f2fs /dev/block/nullb0
> make_f2fs -s 128 /dev/block/nullb0
> fio --bs=512k --size=1536M --rw=write --name=1
> --filename=/mnt/test_dir/seq_write
> --ioengine=io_uring --iodepth=64 --end_fsync=1
> 
> before
> SEGS_PER_SEC 1
> 2556MiB/s
> SEGS_PER_SEC 128
> 2145MiB/s
> 
> after
> SEGS_PER_SEC 1
> 2556MiB/s
> SEGS_PER_SEC 128
> 2556MiB/s
> 
> Signed-off-by: yohan.joung <yohan.joung@sk.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,