[PATCH 2/2] xfs/216: disable all concurrency scaling

[PATCH 2/2] xfs/216: disable all concurrency scaling

[Christoph Hellwig]

This test currently disables log concurrency scaling, but even the
data device concurrency scaling can create mismatching output on
systems with a large CPU count.

Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 tests/xfs/216 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/xfs/216 b/tests/xfs/216
index 1749647c11f7..ce8bb528410b 100755
--- a/tests/xfs/216
+++ b/tests/xfs/216
@@ -23,7 +23,7 @@ _cleanup()
 _require_scratch
 _scratch_mkfs_xfs >/dev/null 2>&1
 if _scratch_mkfs_xfs_supports_concurrency -l >> $seqres.full 2>&1; then
-	loop_mkfs_opts="-l concurrency=0"
+	loop_mkfs_opts="-d concurrency=0 -l concurrency=0 -r concurrency=0"
 else
 	loop_mkfs_opts=""
 fi
-- 
2.53.0

Re: [PATCH 2/2] xfs/216: disable all concurrency scaling

[Shin'ichiro Kawasaki]

On Jun 18, 2026 / 15:48, Christoph Hellwig wrote:
> This test currently disables log concurrency scaling, but even the
> data device concurrency scaling can create mismatching output on
> systems with a large CPU count.
> 
> Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Thanks, I confirmed this patch avoid the failure that I reported.

Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>

cpu scaling fixes v2

[Christoph Hellwig]

Hi all,

this series fully disables the mkfs automatic CPU count scaling for two
tests, where that would lead to differences in the gold output.

Changes since v1:
 - only disabling scaling in xfs/078 when it is supported

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

[Christoph Hellwig]

Disable concurrency scaling to avoid mismatching output on systems with
a large CPU count.

Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
---
 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"
-- 
2.53.0

[PATCH 2/2] xfs/216: disable all concurrency scaling

[Christoph Hellwig]

This test currently disables log concurrency scaling, but even the
data device concurrency scaling can create mismatching output on
systems with a large CPU count.

Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
---
 tests/xfs/216 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/xfs/216 b/tests/xfs/216
index 1749647c11f7..ce8bb528410b 100755
--- a/tests/xfs/216
+++ b/tests/xfs/216
@@ -23,7 +23,7 @@ _cleanup()
 _require_scratch
 _scratch_mkfs_xfs >/dev/null 2>&1
 if _scratch_mkfs_xfs_supports_concurrency -l >> $seqres.full 2>&1; then
-	loop_mkfs_opts="-l concurrency=0"
+	loop_mkfs_opts="-d concurrency=0 -l concurrency=0 -r concurrency=0"
 else
 	loop_mkfs_opts=""
 fi
-- 
2.53.0

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

[Eric Sandeen]

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 <shinichiro.kawasaki@wdc.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>

Reviewed-by: Eric Sandeen <sandeen@redhat.com>

> ---
>  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"

Re: [PATCH 2/2] xfs/216: disable all concurrency scaling

[Eric Sandeen]

On 6/19/26 12:09 AM, Christoph Hellwig wrote:
> This test currently disables log concurrency scaling, but even the
> data device concurrency scaling can create mismatching output on
> systems with a large CPU count.
> 
> Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>

Reviewed-by: Eric Sandeen <sandeen@redhat.com>

> ---
>  tests/xfs/216 | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/xfs/216 b/tests/xfs/216
> index 1749647c11f7..ce8bb528410b 100755
> --- a/tests/xfs/216
> +++ b/tests/xfs/216
> @@ -23,7 +23,7 @@ _cleanup()
>  _require_scratch
>  _scratch_mkfs_xfs >/dev/null 2>&1
>  if _scratch_mkfs_xfs_supports_concurrency -l >> $seqres.full 2>&1; then
> -	loop_mkfs_opts="-l concurrency=0"
> +	loop_mkfs_opts="-d concurrency=0 -l concurrency=0 -r concurrency=0"
>  else
>  	loop_mkfs_opts=""
>  fi

Re: [PATCH 2/2] xfs/216: disable all concurrency scaling

[Darrick J. Wong]

On Fri, Jun 19, 2026 at 07:09:29AM +0200, Christoph Hellwig wrote:
> This test currently disables log concurrency scaling, but even the
> data device concurrency scaling can create mismatching output on
> systems with a large CPU count.
> 
> Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> ---
>  tests/xfs/216 | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/xfs/216 b/tests/xfs/216
> index 1749647c11f7..ce8bb528410b 100755
> --- a/tests/xfs/216
> +++ b/tests/xfs/216
> @@ -23,7 +23,7 @@ _cleanup()
>  _require_scratch
>  _scratch_mkfs_xfs >/dev/null 2>&1
>  if _scratch_mkfs_xfs_supports_concurrency -l >> $seqres.full 2>&1; then
> -	loop_mkfs_opts="-l concurrency=0"
> +	loop_mkfs_opts="-d concurrency=0 -l concurrency=0 -r concurrency=0"

/me notes that -lconcurrency is not compatible with -llogdev and the
loopdev is not formatted with SCRATCH_MKFS_OPTIONS, so this won't work
to disable the concurrency= mkfs options if fstests is being run with
SCRATCH_LOGDEV set.

--D

>  else
>  	loop_mkfs_opts=""
>  fi
> -- 
> 2.53.0
> 
>