Re: [PATCH 05/11] selftests: net/fcnal: kill_procs via spin instead of sleep

From: David Ahern <dsahern@gmail.com>
To: Leonard Crestez <cdleonard@gmail.com>,
	Jakub Kicinski <kuba@kernel.org>, Shuah Khan <shuah@kernel.org>,
	David Ahern <dsahern@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>,
	Ido Schimmel <idosch@nvidia.com>,
	Seth David Schoen <schoen@loyalty.org>,
	netdev@vger.kernel.org, linux-kselftest@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 05/11] selftests: net/fcnal: kill_procs via spin instead of sleep
Date: Wed, 6 Oct 2021 08:45:01 -0600	[thread overview]
Message-ID: <b1a213d5-470d-637d-4e78-1b7653d87041@gmail.com> (raw)
In-Reply-To: <ff71285715d47b8c9b6bedb3b50700a26bc81f41.1633520807.git.cdleonard@gmail.com>

On 10/6/21 5:47 AM, Leonard Crestez wrote:
> Sleeping for one second after a kill is not necessary and adds up quite
> quickly. Replace with a fast loop spinning until pidof returns nothing.
> 
> Signed-off-by: Leonard Crestez <cdleonard@gmail.com>
> ---
>  tools/testing/selftests/net/fcnal-test.sh | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/net/fcnal-test.sh b/tools/testing/selftests/net/fcnal-test.sh
> index 0bd60cd3bc06..b7fda51deb3f 100755
> --- a/tools/testing/selftests/net/fcnal-test.sh
> +++ b/tools/testing/selftests/net/fcnal-test.sh
> @@ -176,12 +176,19 @@ show_hint()
>  	fi
>  }
>  
>  kill_procs()
>  {
> -	killall nettest ping ping6 >/dev/null 2>&1
> -	sleep 1
> +	local pids
> +	while true; do
> +		pids=$(pidof nettest ping ping6)
> +		if [[ -z $pids ]]; then
> +			break
> +		fi
> +		kill $pids
> +		sleep 0.01
> +	done
>  }
>  
>  do_run_cmd()
>  {
>  	local cmd="$*"
> 

ideally the script keeps track of processes it launches and only kills
those. The original killall was just a stop gap until the process
tracking was added.