Re: [PATCH v4 33/35] maple_tree: Update testing code for mas_{next,prev,walk}

["Liam R. Howlett" <Liam.Howlett@Oracle.com>]

* Peng Zhang <zhangpeng.00@bytedance.com> [230704 11:11]:
> 
> 
> 在 2023/7/3 02:20, Geert Uytterhoeven 写道:
> > Hi Liam,
> > 
> > On Thu, May 18, 2023 at 9:37 PM Liam R. Howlett <Liam.Howlett@oracle.com> wrote:
> > > Now that the functions have changed the limits, update the testing of
> > > the maple tree to test these new settings.
> > > 
> > > Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> > 
> > Thanks for your patch, which is now commit eb2e817f38cafbf7
> > ("maple_tree: update testing code for mas_{next,prev,walk}") in
> > 
> > > --- a/lib/test_maple_tree.c
> > > +++ b/lib/test_maple_tree.c
> > > @@ -2011,7 +2011,7 @@ static noinline void __init next_prev_test(struct maple_tree *mt)
> > > 
> > >          val = mas_next(&mas, ULONG_MAX);
> > >          MT_BUG_ON(mt, val != NULL);
> > > -       MT_BUG_ON(mt, mas.index != ULONG_MAX);
> > > +       MT_BUG_ON(mt, mas.index != 0x7d6);
> > 
> > On m68k (ARAnyM):
> > 
> >      TEST STARTING
> > 
> >      BUG at next_prev_test:2014 (1)
> >      Pass: 3749128 Run:3749129
> > 
> > And after that it seems to hang[*].
> > 
> > After adding a debug print (thus shifting all line numbers by +1):
> > 
> >      next_prev_test:mas.index = 0x138e
> >      BUG at next_prev_test:2015 (1)
> > 
> > 0x138e = 5006, while the expected value is 0x7d6 = 2006.
> I took a look. The return value 5006 is correct while the
> expected value is wrong. This is a problem with the test,
> it is not compatible with 32-bit systems.

Thanks.  There are a number of tests which deal with larger numbers that
do not work for the 32 bit systems.  Those tests are put within an ifdef
to avoid running.  I guess this one will either need to be altered to be
32 bit safe or added to that list.

> > 
> > I guess converting this test to the KUnit framework would make it a
> > bit easier to investigate failures...
> > 
> > [*] Left the debug one running, and I got a few more:
> > 
> >      BUG at check_empty_area_window:2656 (1)
> >      Pass: 3754275 Run:3754277
> >      BUG at check_empty_area_window:2657 (1)
> >      Pass: 3754275 Run:3754278
> >      BUG at check_empty_area_window:2658 (1)
> >      Pass: 3754275 Run:3754279
> >      BUG at check_empty_area_window:2662 (1)
> >      Pass: 3754275 Run:3754280
> >      BUG at check_empty_area_window:2663 (1)
> >      Pass: 3754275 Run:3754281
> >      maple_tree: 3804518 of 3804524 tests passed
> > 
> > So the full test took more than 20 minutes...

There are a large number of test which are probably going to take a long
time to run.  I'm not sure what should be limited to avoid testing
taking a long time on old systems or even what would be acceptable?

> > 
> > >          MT_BUG_ON(mt, mas.last != ULONG_MAX);
> > > 
> > >          val = mas_prev(&mas, 0);
> > 
> > Gr{oetje,eeting}s,
> > 
> >                          Geert
> > 
> > --
> > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> > 
> > In personal conversations with technical people, I call myself a hacker. But
> > when I'm talking to journalists I just say "programmer" or something like that.
> >                                  -- Linus Torvalds