[LTP] [PATCH 1/1] zram01.sh: Workaround division by 0 on vfat on ppc64le

[Li Wang]

Hi Petr,

On Tue, Nov 8, 2022 at 3:12 AM Petr Vorel <pvorel@suse.cz> wrote:

> Repeatedly read /sys/block/zram*/mm_stat for 1 sec. This should fix bug
> on ppc64le on stable kernels, where mem_used_total is often 0.
>
> Signed-off-by: Petr Vorel <pvorel@suse.cz>
> ---
>  .../kernel/device-drivers/zram/zram01.sh      | 27 +++++++++++++++++--
>  1 file changed, 25 insertions(+), 2 deletions(-)
>
> diff --git a/testcases/kernel/device-drivers/zram/zram01.sh
> b/testcases/kernel/device-drivers/zram/zram01.sh
> index 58d233f91..76a8ccab4 100755
> --- a/testcases/kernel/device-drivers/zram/zram01.sh
> +++ b/testcases/kernel/device-drivers/zram/zram01.sh
> @@ -105,6 +105,26 @@ zram_mount()
>         tst_res TPASS "mount of zram device(s) succeeded"
>  }
>
> +read_mem_used_total()
> +{
> +       echo $(awk '{print $3}' $1)
> +}
> +
> +# Reads /sys/block/zram*/mm_stat until mem_used_total is not 0.
> +loop_read_mem_used_total()
>

This is not a looping function to check if mem_used_total is equal to zero,
the loop part is by means of the TST_RETRY_FUNC macro.

So, I'd suggest renaming it to check_read_mem_used_total().

Reviewed-by: Li Wang <liwang@redhat.com>



> +{
> +       local file="$1"
> +       local mem_used_total
> +
> +       tst_res TINFO "$file"
> +       cat $file >&2
> +
> +       mem_used_total=$(read_mem_used_total $file)
> +       [ "$mem_used_total" -eq 0 ] && return 1
> +
> +       return 0
> +}
> +
>  zram_fill_fs()
>  {
>         local mem_used_total
> @@ -133,9 +153,12 @@ zram_fill_fs()
>                         continue
>                 fi
>
> -               mem_used_total=`awk '{print $3}'
> "/sys/block/zram$i/mm_stat"`
> +               TST_RETRY_FUNC "loop_read_mem_used_total
> /sys/block/zram$i/mm_stat" 0
> +               mem_used_total=$(read_mem_used_total
> /sys/block/zram$i/mm_stat)
> +               tst_res TINFO "mem_used_total: $mem_used_total"
> +
>                 v=$((100 * 1024 * $b / $mem_used_total))
> -               r=`echo "scale=2; $v / 100 " | bc`
> +               r=$(echo "scale=2; $v / 100 " | bc)
>
>                 if [ "$v" -lt 100 ]; then
>                         tst_res TFAIL "compression ratio: $r:1"
> --
> 2.38.0
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>
>

-- 
Regards,
Li Wang
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