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

Zorro Lang
2021-01-28T02:47:03Z

On Wed, Jan 27, 2021 at 03:43:40PM -0800, Darrick J. Wong wrote:
> 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

The root user isn't under this restriction, only g/233 and g/270 run fsstress
with non-root user ($qa_user).
Hmm... is that possible to run xfstests with a non-root user? Or you'd like to
write a common helper _fsstress() (if run fsx with non-root user, I doubt it's
needed too)...

Thanks,
Zorro

>
> --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
> >
>