Re: [PATCH 3/5] lib/bitmap: add test for bitmap_{from,to}_arr64

[Yury Norov]

On Thu, May 19, 2022 at 11:04 AM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> On 5/19/22 09:01, Yury Norov wrote:
> > On Thu, May 19, 2022 at 8:09 AM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> >>
> >> On Thu, Apr 28, 2022 at 01:51:14PM -0700, Yury Norov wrote:
> >>> Test newly added bitmap_{from,to}_arr64() functions similarly to
> >>> already existing bitmap_{from,to}_arr32() tests.
> >>>
> >>> Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
> >>
> >> With this patch in linux-next (including next-20220519), I see lots of
> >> bitmap test errors when booting 32-bit ppc images in qemu. Examples:
> >>
> >> test_bitmap: [lib/test_bitmap.c:600] bitmaps contents differ: expected "0", got "0,65"
> >> ...
> >> test_bitmap: [lib/test_bitmap.c:600] bitmaps contents differ: expected "0,65", got "0,65,128"
> >> test_bitmap: [lib/test_bitmap.c:600] bitmaps contents differ: expected "0,65", got "0,65,128-129"
> >> test_bitmap: [lib/test_bitmap.c:600] bitmaps contents differ: expected "0,65", got "0,65,128-130"
> >> ...
> >> test_bitmap: [lib/test_bitmap.c:600] bitmaps contents differ: expected "0,65,128-143", got "0,65,128-143,208-209"
> >> test_bitmap: [lib/test_bitmap.c:600] bitmaps contents differ: expected "0,65,128-143", got "0,65,128-143,208-210"
> >>
> >> and so on. It only  gets worse from there, and ends with:
> >>
> >> test_bitmap: parselist: 14: input is '0-2047:128/256' OK, Time: 4274
> >> test_bitmap: bitmap_print_to_pagebuf: input is '0-32767
> >> ', Time: 127267
> >> test_bitmap: failed 337 out of 3801 tests
> >>
> >> Other architectures and 64-bit ppc builds seem to be fine.
> >
> > Hi Guenter,
> >
> > Thanks for letting me know. It's really weird because it has already
> > been for 2 weeks
> > in next with no issues. But I tested it on mips32, not powerpc. I'll
> > check what happens
> > there.
> >
> Oh, I have seen the problem for a while, it is just that -next is in
> such a bad shape that it is difficult to bisect individual problems.
>
> > Can you please share your config and qemu image if possible?
> >
>
> First, you have to revert commit b033767848c411
> ("powerpc/code-patching: Use jump_label for testing freed initmem")
> to avoid a crash. After that, a recent version of qemu should work
> with the following command line.
>
> qemu-system-ppc -kernel arch/powerpc/boot/uImage -M mpc8544ds \
>         -m 256 -no-reboot -initrd rootfs.cpio \
>         --append "rdinit=/sbin/init coherent_pool=512k mem=256M console=ttyS0" \
>         -monitor none -nographic
>
> Configuration is mpc85xx_defconfig with CONFIG_TEST_BITMAP enabled.
> I used the root file system (initrd) from
> https://github.com/groeck/linux-build-test/blob/master/rootfs/ppc/rootfs.cpio.gz

Yes, that helped a lot. Thanks, I was able to reproduce it. I'll take
a look shortly.

Thanks,
Yury