charge_reserved_hugetlb.sh tears down background writers with
killall from psmisc. Minimal Ubuntu images do not always provide
that tool, so the selftest fails in cleanup for an environment reason
rather than for the hugetlb behavior it is trying to cover.

Skip the test when killall is unavailable, similar to the existing
root check, so these environments report the dependency clearly
instead of failing the test.

Signed-off-by: Cao Ruichuang <create0818@163.com>
---
v2:
- replace the PID tracking approach with a simple skip when killall is
  unavailable
- follow Mike Rapoport's review suggestion

 tools/testing/selftests/mm/charge_reserved_hugetlb.sh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
index 44776965763..44f4e703deb 100755
--- a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
+++ b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
@@ -11,6 +11,11 @@ if [[ $(id -u) -ne 0 ]]; then
   exit $ksft_skip
 fi
 
+if ! command -v killall >/dev/null 2>&1; then
+  echo "killall not available. Skipping..."
+  exit $ksft_skip
+fi
+
 nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages)
 
 fault_limit_file=limit_in_bytes
-- 
2.39.5 (Apple Git-154)

On 4/10/26 06:41, Cao Ruichuang wrote:
> charge_reserved_hugetlb.sh tears down background writers with
> killall from psmisc. Minimal Ubuntu images do not always provide
> that tool, so the selftest fails in cleanup for an environment reason
> rather than for the hugetlb behavior it is trying to cover.
> 
> Skip the test when killall is unavailable, similar to the existing
> root check, so these environments report the dependency clearly
> instead of failing the test.
> 
> Signed-off-by: Cao Ruichuang <create0818@163.com>
> ---

Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>

-- 
Cheers,

David

On Fri, 10 Apr 2026 12:41:39 +0800 Cao Ruichuang <create0818@163.com> wrote:

> charge_reserved_hugetlb.sh tears down background writers with
> killall from psmisc. Minimal Ubuntu images do not always provide
> that tool, so the selftest fails in cleanup for an environment reason
> rather than for the hugetlb behavior it is trying to cover.
> 
> Skip the test when killall is unavailable, similar to the existing
> root check, so these environments report the dependency clearly
> instead of failing the test.
> 
> Signed-off-by: Cao Ruichuang <create0818@163.com>

Reviewed-by: SeongJae Park <sj@kernel.org>

> ---
> v2:
> - replace the PID tracking approach with a simple skip when killall is
>   unavailable
> - follow Mike Rapoport's review suggestion

I was actually thinking if PID tracking approach is better reading this
chagelog.  But simple skipping also makes sense to me.

Btw, adding a link to the previous version [1] would be nice.

[1] https://docs.kernel.org/process/submitting-patches.html#commentary


Thanks,
SJ

[...]

On Fri, Apr 10, 2026 at 12:41:39PM +0800, Cao Ruichuang wrote:
> charge_reserved_hugetlb.sh tears down background writers with
> killall from psmisc. Minimal Ubuntu images do not always provide
> that tool, so the selftest fails in cleanup for an environment reason
> rather than for the hugetlb behavior it is trying to cover.
> 
> Skip the test when killall is unavailable, similar to the existing
> root check, so these environments report the dependency clearly
> instead of failing the test.
> 
> Signed-off-by: Cao Ruichuang <create0818@163.com>

Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

> ---
> v2:
> - replace the PID tracking approach with a simple skip when killall is
>   unavailable
> - follow Mike Rapoport's review suggestion
> 
>  tools/testing/selftests/mm/charge_reserved_hugetlb.sh | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
> index 44776965763..44f4e703deb 100755
> --- a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
> +++ b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
> @@ -11,6 +11,11 @@ if [[ $(id -u) -ne 0 ]]; then
>    exit $ksft_skip
>  fi
>  
> +if ! command -v killall >/dev/null 2>&1; then
> +  echo "killall not available. Skipping..."
> +  exit $ksft_skip
> +fi
> +
>  nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages)
>  
>  fault_limit_file=limit_in_bytes
> -- 
> 2.39.5 (Apple Git-154)
> 

-- 
Sincerely yours,
Mike.