Re: [PATCH] selftests/livepatch: define max test-syscall processes

From: Marcos Paulo de Souza
Date: Thu Jun 06 2024 - 14:28:17 EST


On Thu, 2024-06-06 at 09:53 -0400, Ryan Sullivan wrote:
> Define a maximum allowable number of pids that can be livepatched in
> test-syscall.sh as with extremely large machines the output from a
> large number of processes overflows the dev/kmsg "expect" buffer in
> the "check_result" function and causes a false error.
>
> Reported-by: CKI Project <cki-project@xxxxxxxxxx>
> Signed-off-by: Ryan Sullivan <rysulliv@xxxxxxxxxx>

Hi Ryan,

is this the same patch that you sent on ? I couldn't spot any changes,
and you also didn't tagged a different version for this patch.

> ---
>  tools/testing/selftests/livepatch/test-syscall.sh | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/livepatch/test-syscall.sh
> b/tools/testing/selftests/livepatch/test-syscall.sh
> index b76a881d4013..289eb7d4c4b3 100755
> --- a/tools/testing/selftests/livepatch/test-syscall.sh
> +++ b/tools/testing/selftests/livepatch/test-syscall.sh
> @@ -15,7 +15,10 @@ setup_config
>  
>  start_test "patch getpid syscall while being heavily hammered"
>  
> -for i in $(seq 1 $(getconf _NPROCESSORS_ONLN)); do
> +NPROC=$(getconf _NPROCESSORS_ONLN)
> +MAXPROC=128
> +
> +for i in $(seq 1 $(($NPROC < $MAXPROC ? $NPROC : $MAXPROC))); do
>   ./test_klp-call_getpid &
>   pids[$i]="$!"
>  done