Re: [PATCH v5] erofs: support deflate decompress by using Intel QAT

[Gao Xiang <hsiangkao@linux.alibaba.com>]

Hi Bo,

On 2025/5/22 14:16, Bo Liu wrote:
> This patch introdueces the use of the Intel QAT to decompress compressed
> data in the EROFS filesystem, aiming to improve the decompression speed
> of compressed datea.
> 
> We created a 285MiB compressed file and then used the following command to
> create EROFS images with different cluster size.
>       # mkfs.erofs -zdeflate,level=9 -C16384
> 
> fio command was used to test random read and small random read(~5%) and
> sequential read performance.
>       # fio -filename=testfile  -bs=4k -rw=read -name=job1
>       # fio -filename=testfile  -bs=4k -rw=randread -name=job1
>       # fio -filename=testfile  -bs=4k -rw=randread --io_size=14m -name=job1
> 
> Here are some performance numbers for reference:
> 
> Processors: Intel(R) Xeon(R) 6766E(144 core)
> Memory:     521 GiB
> 
> |-----------------------------------------------------------------------------|
> |           | Cluster size | sequential read | randread  | small randread(5%) |
> |-----------|--------------|-----------------|-----------|--------------------|
> | Intel QAT |    4096      |    538  MiB/s   | 112 MiB/s |     20.76 MiB/s    |
> | Intel QAT |    16384     |    699  MiB/s   | 158 MiB/s |     21.02 MiB/s    |
> | Intel QAT |    65536     |    917  MiB/s   | 278 MiB/s |     20.90 MiB/s    |
> | Intel QAT |    131072    |    1056 MiB/s   | 351 MiB/s |     23.36 MiB/s    |
> | Intel QAT |    262144    |    1145 MiB/s   | 431 MiB/s |     26.66 MiB/s    |
> | deflate   |    4096      |    499  MiB/s   | 108 MiB/s |     21.50 MiB/s    |
> | deflate   |    16384     |    422  MiB/s   | 125 MiB/s |     18.94 MiB/s    |
> | deflate   |    65536     |    452  MiB/s   | 159 MiB/s |     13.02 MiB/s    |
> | deflate   |    131072    |    452  MiB/s   | 177 MiB/s |     11.44 MiB/s    |
> | deflate   |    262144    |    466  MiB/s   | 194 MiB/s |     10.60 MiB/s    |
> 
> Signed-off-by: Bo Liu <liubo03@inspur.com>
> ---
> v1: https://lore.kernel.org/linux-erofs/20250410042048.3044-1-liubo03@inspur.com/
> v2: https://lore.kernel.org/linux-erofs/20250410042048.3044-1-liubo03@inspur.com/T/#t
> v3: https://lore.kernel.org/linux-erofs/20250516082634.3801-1-liubo03@inspur.com/
> v4: https://lore.kernel.org/linux-erofs/20250521100326.2867828-1-hsiangkao@linux.alibaba.com/
> change since v4:
>   - add sysfs documentation.
> 
>   Documentation/ABI/testing/sysfs-fs-erofs |  12 ++
>   fs/erofs/Kconfig                         |  14 ++
>   fs/erofs/Makefile                        |   1 +
>   fs/erofs/compress.h                      |  10 ++
>   fs/erofs/decompressor_crypto.c           | 186 +++++++++++++++++++++++
>   fs/erofs/decompressor_deflate.c          |  17 ++-
>   fs/erofs/sysfs.c                         |  34 ++++-
>   fs/erofs/zdata.c                         |   1 +
>   8 files changed, 272 insertions(+), 3 deletions(-)
>   create mode 100644 fs/erofs/decompressor_crypto.c
> 
> diff --git a/Documentation/ABI/testing/sysfs-fs-erofs b/Documentation/ABI/testing/sysfs-fs-erofs
> index b134146d735b..95201a62f704 100644
> --- a/Documentation/ABI/testing/sysfs-fs-erofs
> +++ b/Documentation/ABI/testing/sysfs-fs-erofs
> @@ -27,3 +27,15 @@ Description:	Writing to this will drop compression-related caches,
>   		- 1 : invalidate cached compressed folios
>   		- 2 : drop in-memory pclusters
>   		- 3 : drop in-memory pclusters and cached compressed folios
> +
> +What:		/sys/fs/erofs/accel
> +Date:		May 2025
> +Contact:	"Bo Liu" <liubo03@inspur.com>
> +Description:	The accel file is read-write and allows to set or show
> +		hardware decompression accelerators, and it supports writing
> +		multiple accelerators separated by ‘\n’.

		Used to set or show hardware accelerators in effect and multiple
		accelerators are separated by '\n'.

		Supported accelerator(s): qat_deflate

		Disable all accelerators with an empty string (echo > accel).

> +		Currently supported accelerators:

...

> +
> +static int __z_erofs_crypto_decompress(struct z_erofs_decompress_req *rq,
> +				struct crypto_acomp *tfm)
> +{
> +	struct sg_table st_src, st_dst;
> +	struct acomp_req *req;
> +	struct crypto_wait wait;
> +	u8 *headpage;
> +	int ret;
> +
> +	headpage = kmap_local_page(*rq->in);
> +	ret = z_erofs_fixup_insize(rq, headpage + rq->pageofs_in,
> +				min_t(unsigned int, rq->inputsize,
> +							rq->sb->s_blocksize - rq->pageofs_in));

	ret = z_erofs_fixup_insize(rq, headpage + rq->pageofs_in,
				min_t(unsigned int, rq->inputsize,
				      rq->sb->s_blocksize - rq->pageofs_in));

Otherwise it looks good to me.

Thanks,
Gao Xiang