Re: [PATCH 2/2] mm/page_alloc: Allow high-order pages to be stored on the per-cpu lists

[Mel Gorman <mgorman@techsingularity.net>]

On Wed, Jun 09, 2021 at 02:30:18PM -0400, Zi Yan wrote:
> On 3 Jun 2021, at 10:22, Mel Gorman wrote:
> > Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
> > Acked-by: Vlastimil Babka <vbabka@suse.cz>
> > ---
> >  include/linux/mmzone.h |  20 +++++-
> >  mm/internal.h          |   2 +-
> >  mm/page_alloc.c        | 159 +++++++++++++++++++++++++++++------------
> >  mm/swap.c              |   2 +-
> >  4 files changed, 135 insertions(+), 48 deletions(-)
> >
> 
> Hi Mel,
> 
> I am not able to boot my QEMU VM with v5.13-rc5-mmotm-2021-06-07-18-33.
> git bisect points to this patch. The VM got stuck at ???Booting from ROM??????.
> 
> My kernel config is attached and my qemu command is:
> 
> qemu-system-x86_64 -kernel ~/repos/linux-1gb-thp/arch/x86/boot/bzImage \
>     -drive file=~/qemu-image/vm.qcow2,if=virtio \
>     -append "nokaslr root=/dev/vda1 rw console=ttyS0 " \
>     -pidfile vm.pid \
>     -netdev user,id=mynet0,hostfwd=tcp::11022-:22 \
>     -device virtio-net-pci,netdev=mynet0 \
>     -m 16g -smp 6 -cpu host -enable-kvm -nographic \
>     -machine hmat=on -object memory-backend-ram,size=8g,id=m0 \
>     -object memory-backend-ram,size=8g,id=m1 \
>     -numa node,memdev=m0,nodeid=0 -numa node,memdev=m1,nodeid=1
> 
> The attached config has THP disabled. The VM cannot boot with THP enabled,
> either.
> 

There is not a lot of information to go on here. Can you confirm that a
revert of that specific patch from mmotm-2021-06-07-18-33 also boots? It
sounds like your console log is empty, does anything useful appear if
you add "earlyprintk=serial,ttyS0,115200" to the kernel command line?

-- 
Mel Gorman
SUSE Labs