On Wed, Feb 23, 2022 at 11:54 AM Darrick J. Wong <djwong@xxxxxxxxxx> wrote:
>
> On Tue, Feb 08, 2022 at 04:52:30PM -0500, Anna Schumaker wrote:
> > From: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
> >
> > The comment up top says this is a stress test, so at the very least it
> > should be added to this group. As for removing it from the quick group,
> > making this test variable on the number of CPUs means this test could
> > take a very long time to finish (I'm unsure exactly how long on NFS v4.1
> > because I usually kill it after a half hour or so)
> >
> > Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
> > ---
> > I have thought of two alternatives to this patch that would work for me:
> > 1) Could we add an _unsupported_fs function which is the opposite of
> > _supported_fs to prevent tests from running on specific filesystems?
> > 2) Would it be okay to check if $FSTYP == "nfs" when setting nr_cpus,
> > and set it to 1 instead? Perhaps through a function in common/rc
> > that other tests can use if they scale work based on cpu-count?
>
> How about we create a function to estimate fs threading scalability?
> There are probably (simple) filesystems out there with a Big Filesystem
> Lock that won't benefit from more CPUs pounding on it...
>
> # Estimate how many writer threads we should start to stress test this
> # type of filesystem.
> _estimate_threading_factor() {
> case "$FSTYP" in
> "nfs")
> echo 1;;
> *)
> echo $((2 * $(getconf _NPROCESSORS_ONLN) ));;
> esac
> }
>
> and later:
>
> nr_cpus=$(_estimate_threading_factor)
>
> Once something like this is landed, we can customize for each FSTYP. I
> suspect that XFS on spinning rust might actually want "2" here, not
> nr_cpus*2, given the sporadic complaints about this test taking much
> longer for a few people.
Sure. Should I do a `git grep` for "nr_cpus" on the other tests and
update them all at the same time, or just leave it with this one file
to start?
Anna
>
> > ---
> > tests/generic/531 | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tests/generic/531 b/tests/generic/531
> > index 5e84ca977b44..62e3cac92423 100755
> > --- a/tests/generic/531
> > +++ b/tests/generic/531
> > @@ -12,7 +12,7 @@
> > # Use every CPU possible to stress the filesystem.
> > #
> > . ./common/preamble
> > -_begin_fstest auto quick unlink
> > +_begin_fstest auto stress unlink
>
> As for this change itself,
> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> --D
>
>
> > testfile=$TEST_DIR/$seq.txt
> >
> > # Import common functions.
> > --
> > 2.35.1
> >
