Re: [PATCH 1/2] xfs/078: disable all concurrency scaling

On 6/19/26 12:09 AM, Christoph Hellwig wrote:
> Disable concurrency scaling to avoid mismatching output on systems with
> a large CPU count.
> 
> Reported-by: Shin'ichiro Kawasaki <[email protected]>
> Signed-off-by: Christoph Hellwig <[email protected]>
> Tested-by: Shin'ichiro Kawasaki <[email protected]>

Reviewed-by: Eric Sandeen <[email protected]>

> ---
>  tests/xfs/078 | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/tests/xfs/078 b/tests/xfs/078
> index 6057aeea12ab..408170ae57f5 100755
> --- a/tests/xfs/078
> +++ b/tests/xfs/078
> @@ -57,9 +57,16 @@ _grow_loop()
>  	$XFS_IO_PROG -f -c "truncate $original" $LOOP_IMG
>  	loop_dev=`_create_loop_device $LOOP_IMG $bsize`
>  
> -	dparam=""
> +	# Disable concurrency scaling to avoid output differences due to large
> +	# CPU counts.
> +	if _scratch_mkfs_xfs_supports_concurrency -l >> $seqres.full 2>&1; then
> +		mkfs_opts="-d concurrency=0 -l concurrency=0 -r concurrency=0"
> +	else
> +		mkfs_opts=""
> +	fi
> +
>  	if [ -n "$agsize" ]; then
> -		dparam="-d agsize=$agsize"
> +		mkfs_opts="$mkfs_opts -d agsize=$agsize"
>  	fi
>  
>  	echo
> @@ -67,7 +74,7 @@ _grow_loop()
>  	echo
>  
>  	echo "*** mkfs loop file (size=$original)"
> -	$MKFS_XFS_PROG -b size=$bsize $dparam $loop_dev | \
> +	$MKFS_XFS_PROG -b size=$bsize $mkfs_opts $loop_dev | \
>  		_filter_mkfs 2>/dev/null
>  
>  	echo "*** extend loop file"