[LTP] [PATCH 2/3] zram/zram_lib.sh: Skip test if zram module can not be removed

[xuyang2018.jy@fujitsu.com]

Hi Petr
> Hi Xu, Cyril,
>
>> Hi!
>>>   	tst_set_timeout $((dev_num*450))
>
>>> +	rmmod zram>  /dev/null 2>&1 || tst_brk TCONF "zram module is being used"
> This is wrong:
>
> $ lsmod | grep zram
> # rmmod zram; echo $?
> rmmod: ERROR: Module zram is not currently loaded
> 1
>
> Why not detect with lsmod? i.e.:
>
> 	if lsmod | grep zram; then
> 		rmmod zram>  /dev/null 2>&1 || tst_brk TCONF "zram module is being used"
> 	fi
>
Yes
> Although I'm not sure if we should attempt to rmmod, maybe quit when lsmod
> detects zram would be better.
If zram module was loaded but not used, then we can rmmod and do 
modprobe(case needs a clean zram envrionment). IMO, it doesn't affect 
any things.
If zram module was loaded but used, then rmmod failed and case skips.

ps: zram01 need to rmmod and modprobe zram. So if kernel built with 
CONFIG_ZRAM=y, we also need to TCONF. But it is another story.
>
> Also it wouldn't harm to add at least rmmod into TST_NEEDS_CMDS (in the
> zram_lib.sh + take into account TST_NEEDS_CMDS from tests), but that's another
> story.
Agree.

Best Regards
Yang Xu
>
> Kind regards,
> Petr