Re: [PATCH] generic/233,270: unlimit the max locked memory size for io_uring

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Jan 27, 2021 at 03:21:43PM +0800, Zorro Lang wrote:
> The ltp/fsstress always fails on io_uring_queue_init() by returnning
> ENOMEM. Due to io_uring accounts memory it needs under the rlimit
> memlocked option, which can be quite low on some setups, especially
> on 64K pagesize machine. root isn't under this restriction, but
> regular users are. So only g/233 and g/270 which use $qa_user to run
> fsstress are failed.
> 
> To avoid this failure, set max locked memory to unlimited before doing
> fsstress, then restore it after test done.
> 
> Signed-off-by: Zorro Lang <zlang@redhat.com>
> ---
>  tests/generic/233 | 8 ++++++++
>  tests/generic/270 | 8 ++++++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/tests/generic/233 b/tests/generic/233
> index 7eda5774..342690c2 100755
> --- a/tests/generic/233
> +++ b/tests/generic/233
> @@ -43,6 +43,13 @@ _fsstress()
>  -f rename=10 -f fsync=2 -f write=15 -f dwrite=15 \
>  -n $count -d $out -p 7`
>  
> +	# io_uring accounts memory it needs under the rlimit memlocked option,
> +	# which can be quite low on some setups (especially 64K pagesize). root
> +	# isn't under this restriction, but regular users are. To avoid the
> +	# io_uring_queue_init fail on ENOMEM, set max locked memory to unlimited
> +	# temporarily.
> +	lmem=`ulimit -l`
> +	ulimit -l unlimited

Should this apply to all the other tests that run fsstress?

$ grep -l FSSTRESS_PROG tests/ | wc -l
94

--D

>  	echo "fsstress $args" >> $seqres.full
>  	if ! su $qa_user -c "$FSSTRESS_PROG $args" | tee -a $seqres.full | _filter_num
>  	then
> @@ -50,6 +57,7 @@ _fsstress()
>  		cat $tmp.out | tee -a $seqres.full
>  		status=1
>  	fi
> +	ulimit -l $lmem
>  }
>  
>  # real QA test starts here
> diff --git a/tests/generic/270 b/tests/generic/270
> index 3d8656d4..bd52d56e 100755
> --- a/tests/generic/270
> +++ b/tests/generic/270
> @@ -37,6 +37,13 @@ _workout()
>  	cp $FSSTRESS_PROG  $tmp.fsstress.bin
>  	$SETCAP_PROG cap_chown=epi  $tmp.fsstress.bin
>  
> +	# io_uring accounts memory it needs under the rlimit memlocked option,
> +	# which can be quite low on some setups (especially 64K pagesize). root
> +	# isn't under this restriction, but regular users are. To avoid the
> +	# io_uring_queue_init fail on ENOMEM, set max locked memory to unlimited
> +	# temporarily.
> +	lmem=`ulimit -l`
> +	ulimit -l unlimited
>  	(su $qa_user -c "$tmp.fsstress.bin $args" &) > /dev/null 2>&1
>  
>  	echo "Run dd writers in parallel"
> @@ -50,6 +57,7 @@ _workout()
>  	done
>  
>  	$KILLALL_PROG -w $tmp.fsstress.bin
> +	ulimit -l $lmem
>  }
>  
>  # real QA test starts here
> -- 
> 2.29.2
>