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

[Guenter Roeck]

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

Hope this helps,
Guenter