On Wed, Jun 08, 2022 at 11:42:33AM +0900, Sergey Senozhatsky wrote: > On (22/06/08 11:39), Sergey Senozhatsky wrote: > > On (22/06/07 16:52), Minchan Kim wrote: > > > > rootfs: https://oebuilds.tuxbuild.com/29zhlbEc3EWq2wod9Uy964Bp27q/images/am57xx-evm/rpb-console-image-lkft-am57xx-evm-20220601222434.rootfs.ext4.gz > > > > kernel: https://builds.tuxbuild.com/29zhqJJizU2Y7Ka7ArhryUOrNDC/zImage > > > > > > > > Boot command, > > > > /usr/bin/qemu-system-aarch64 -cpu host,aarch64=off -machine > > > > virt-2.10,accel=kvm -nographic -net > > > > nic,model=virtio,maaacaddr=BA:DD:AD:CC:09:04 -net tap -m 2048 -monitor > > > > none -kernel kernel/zImage --append "console=ttyAMA0 root=/dev/vda rw" > > > > -hda rootfs/rpb-console-image-lkft-am57xx-evm-20220601222434.rootfs.ext4 > > > > -m 4096 -smp 2 > > > > > > > > # cd /opt/kselftests/default-in-kernel/zram > > > > # ./zram.sh > > > > > > > > Allow me sometime I will try to bisect this problem. > > > > > > Thanks for sharing the info. > > > > > > I managed to work your rootfs with my local arm build > > > based on the problematic git tip. > > > However, I couldn't suceed to reproduce it. > > > > > > I needed to build zsmalloc/zram built-in instead of modules > > > Is it related? Hmm, > > > > > > Yeah, It would be very helpful if you could help to bisect it. > > > > This looks like a NULL lock->name dereference in lockdep. I suspect > > that somehow local_lock doesn't get .dep_map initialized. Maybe running > > the kernel with CONFIG_DEBUG_LOCK_ALLOC would help us? Naresh, can you > > help us with this? > > Hmm, actually, hold on. mapping_area is per-CPU, so what happens if CPU > get offlined and onlined again? I don't see us re-initializing mapping_area > local_lock_init(&zs_map_area.lock) and so on. I am trying to understand the problem. AFAIK, the mapping_area was static allocation per cpu so in zs_cpu_down, we never free the mapping_area itself. Then, why do we need to reinitialize the local lock again?
