linux-kernel - Re: [PATCH v2] tools/time: access /sys/kernel/debug/udelay

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Date:   Wed, 21 Oct 2020 09:21:43 -0700
From:   David Riley <davidriley@...omium.org>
To:     Hui Su <sh_def@....com>
Cc:     akpm@...ux-foundation.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] tools/time: access /sys/kernel/debug/udelay_test
 before test

Reviewed-by: David Riley <davidriley@...omium.org>

On Wed, Oct 21, 2020 at 8:05 AM Hui Su <sh_def@....com> wrote:
>
> before(when i did not compile udelay_test.ko):
> sh@...ntu:~/workspace/compile/tools/time$ sudo ./udelay_test.sh
> ./udelay_test.sh: line 25: /sys/kernel/debug/udelay_test: Permission denied
> ./udelay_test.sh: line 26: /sys/kernel/debug/udelay_test: No such file or directory
> ./udelay_test.sh: line 25: /sys/kernel/debug/udelay_test: Permission denied
> ./udelay_test.sh: line 26: /sys/kernel/debug/udelay_test: No such file or directory
> ...
> about two hundreds lines.
>
> we access '/sys/kernel/debug/udelay_test' the before starting the
> udelay_test.
>
> now(when i did not compile udelay_test.ko):
> sh@...ntu:~/workspace/linux-stable/tools/time$ sudo ./udelay_test.sh
> modprobe: FATAL: Module udelay_test not found in directory /lib/modules/5.4.44
> ERROR, can not access /sys/kernel/debug/udelay_test.
> modprobe: FATAL: Module udelay_test not found.
>
> ---
> v1->v2: remove the debug_file_exist().
>
> Signed-off-by: Hui Su <sh_def@....com>
> ---
>  tools/time/udelay_test.sh | 42 ++++++++++++++++++++++-----------------
>  1 file changed, 24 insertions(+), 18 deletions(-)
>
> diff --git a/tools/time/udelay_test.sh b/tools/time/udelay_test.sh
> index 6779d7e55d85..c8458d5b7fcd 100755
> --- a/tools/time/udelay_test.sh
> +++ b/tools/time/udelay_test.sh
> @@ -12,10 +12,11 @@
>
>  MODULE_NAME=udelay_test
>  UDELAY_PATH=/sys/kernel/debug/udelay_test
> +retcode=0
>
>  setup()
>  {
> -       /sbin/modprobe -q $MODULE_NAME
> +       /sbin/modprobe $MODULE_NAME
>         tmp_file=`mktemp`
>  }
>
> @@ -31,29 +32,34 @@ cleanup()
>         if [ -f $tmp_file ]; then
>                 rm $tmp_file
>         fi
> -       /sbin/modprobe -q -r $MODULE_NAME
> +       /sbin/modprobe -r $MODULE_NAME
>  }
>
>  trap cleanup EXIT
>  setup
>
> -# Delay for a variety of times.
> -# 1..200, 200..500 (by 10), 500..2000 (by 100)
> -for (( delay = 1; delay < 200; delay += 1 )); do
> -       test_one $delay
> -done
> -for (( delay = 200; delay < 500; delay += 10 )); do
> -       test_one $delay
> -done
> -for (( delay = 500; delay <= 2000; delay += 100 )); do
> -       test_one $delay
> -done
> -
> -# Search for failures
> -count=`grep -c FAIL $tmp_file`
> -if [ $? -eq "0" ]; then
> -       echo "ERROR: $count delays failed to delay long enough"
> +if [ ! -d "$UDELAY_PATH" ]; then
>         retcode=1
> +       echo "ERROR, can not access $UDELAY_PATH."
> +else
> +       # Delay for a variety of times.
> +       # 1..200, 200..500 (by 10), 500..2000 (by 100)
> +       for (( delay = 1; delay < 200; delay += 1 )); do
> +               test_one $delay
> +       done
> +       for (( delay = 200; delay < 500; delay += 10 )); do
> +               test_one $delay
> +       done
> +       for (( delay = 500; delay <= 2000; delay += 100 )); do
> +               test_one $delay
> +       done
> +
> +       # Search for failures
> +       count=`grep -c FAIL $tmp_file`
> +       if [ $? -eq "0" ]; then
> +               echo "ERROR: $count delays failed to delay long enough"
> +               retcode=1
> +       fi
>  fi
>
>  exit $retcode
> --
> 2.25.1
>
>