Re: [PATCH 0/2] Improve the tmpfs large folio read performance

[Kefeng Wang <wangkefeng.wang@huawei.com>]

On 2024/10/16 18:09, Baolin Wang wrote:
> The tmpfs has already supported the PMD-sized large folios, but the tmpfs
> read operation still performs copying at the PAGE SIZE granularity, which
> is not perfect. This patch changes to copy data at the folio granularity,
> which can improve the read performance.
> 
> Use 'fio bs=64k' to read a 1G tmpfs file populated with 2M THPs, and I can
> see about 20% performance improvement, and no regression with bs=4k. I
> also did some functional test with the xfstests suite, and I did not find
> any regressions with the following xfstests config.
>    FSTYP=tmpfs
>    export TEST_DIR=/mnt/tempfs_mnt
>    export TEST_DEV=/mnt/tempfs_mnt
>    export SCRATCH_MNT=/mnt/scratchdir
>    export SCRATCH_DEV=/mnt/scratchdir
> 

Oh，we make same changes, my bonnie test(./bonnie -d /tmp -s 1024) see
similar improvement(19.2% with huge=always) with out inner changes :)

> Baolin Wang (2):
>    mm: shmem: update iocb->ki_pos directly to simplify tmpfs read logic
>    mm: shmem: improve the tmpfs large folio read performance
> 
>   mm/shmem.c | 54 ++++++++++++++++++++++--------------------------------
>   1 file changed, 22 insertions(+), 32 deletions(-)
>