On Tue, Aug 29, 2023 at 04:03:49PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> The write invalidation code in iomap can only be triggered for writes
> that span multiple folios. If the kernel reports a huge page size,
> scale up the write size.
>
> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> ---
> tests/xfs/559 | 29 ++++++++++++++++++++++++++++-
> 1 file changed, 28 insertions(+), 1 deletion(-)
>
>
> diff --git a/tests/xfs/559 b/tests/xfs/559
> index cffe5045a5..64fc16ebfd 100755
> --- a/tests/xfs/559
> +++ b/tests/xfs/559
> @@ -42,11 +42,38 @@ $XFS_IO_PROG -c 'chattr -x' $SCRATCH_MNT &> $seqres.full
> _require_pagecache_access $SCRATCH_MNT
>
> blocks=10
> -blksz=$(_get_page_size)
> +
> +# If this kernel advertises huge page support, it's possible that it could be
> +# using large folios for the page cache writes. It is necessary to write
> +# multiple folios (large or regular) to triggering the write invalidation,
> +# so we'll scale the test write size accordingly.
> +blksz=$(_get_hugepagesize)
Isn't _require_hugepages needed if _get_hugepagesize is used?
Thanks,
Zorro
> +base_pagesize=$(_get_page_size)
> +test -z "$blksz" && blksz=${base_pagesize}
> filesz=$((blocks * blksz))
> dirty_offset=$(( filesz - 1 ))
> write_len=$(( ( (blocks - 1) * blksz) + 1 ))
>
> +# The write invalidation that we're testing below can only occur as part of
> +# a single large write. The kernel limits writes to one base page less than
> +# 2GiB to prevent lengthy IOs and integer overflows. If the block size is so
> +# huge (e.g. 512M huge pages on arm64) that we'd exceed that, reduce the number
> +# of blocks to get us under the limit.
> +max_writesize=$((2147483647 - base_pagesize))
> +if ((write_len > max_writesize)); then
> + blocks=$(( ( (max_writesize - 1) / blksz) + 1))
> + # We need at least three blocks in the file to test invalidation
> + # between writes to multiple folios. If we drop below that,
> + # reconfigure ourselves with base pages and hope for the best.
> + if ((blocks < 3)); then
> + blksz=$base_pagesize
> + blocks=10
> + fi
> + filesz=$((blocks * blksz))
> + dirty_offset=$(( filesz - 1 ))
> + write_len=$(( ( (blocks - 1) * blksz) + 1 ))
> +fi
> +
> # Create a large file with a large unwritten range.
> $XFS_IO_PROG -f -c "falloc 0 $filesz" $SCRATCH_MNT/file >> $seqres.full
>
>
