Re: 5.14.9 aarch64 OOPS Workqueue: btrfs-delalloc btrfs_work_helper

On Tue, Oct 12, 2021 at 2:47 AM Qu Wenruo [off-list ref] wrote:

On 2021/10/12 13:25, Nikolay Borisov wrote:

quoted

On 12.10.21 г. 3:59, Chris Murphy wrote:

quoted

Linux version 5.14.9-300.fc35.aarch64 Fedora-Cloud-Base-35-20211004.n.0.aarch64
[ 2164.477113] Unable to handle kernel paging request at virtual
address fffffffffffffdd0
[ 2164.483166] Mem abort info:
[ 2164.485300]   ESR = 0x96000004
[ 2164.487824]   EC = 0x25: DABT (current EL), IL = 32 bits
[ 2164.493361]   SET = 0, FnV = 0
[ 2164.496336]   EA = 0, S1PTW = 0
[ 2164.498762]   FSC = 0x04: level 0 translation fault
[ 2164.503031] Data abort info:
[ 2164.509584]   ISV = 0, ISS = 0x00000004
[ 2164.516918]   CM = 0, WnR = 0
[ 2164.523438] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000158751000
[ 2164.533628] [fffffffffffffdd0] pgd=0000000000000000, p4d=0000000000000000
[ 2164.543741] Internal error: Oops: 96000004 [#1] SMP
[ 2164.551652] Modules linked in: virtio_gpu virtio_dma_buf
drm_kms_helper cec fb_sys_fops syscopyarea sysfillrect sysimgblt
joydev virtio_net virtio_balloon net_failover failover vfat fat drm
fuse zram ip_tables crct10dif_ce ghash_ce virtio_blk qemu_fw_cfg
virtio_mmio aes_neon_bs
[ 2164.583368] CPU: 2 PID: 8910 Comm: kworker/u8:3 Not tainted
5.14.9-300.fc35.aarch64 #1
[ 2164.593732] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[ 2164.603204] Workqueue: btrfs-delalloc btrfs_work_helper
[ 2164.611402] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
[ 2164.620165] pc : submit_compressed_extents+0x38/0x3d0

Qu isn't this the subpage bug you narrowed down a couple of days ago ?

Not exactly.

The bug I pinned down is inside my refactored code of LZO code, not the
generic part, and my refactored code is not yet merged.

Chris, mind to share the code context of the stack?

From the bug report:

* provision Fedora 35 aarhc64 cloud based VM in openstack
* try rebuilding kernel rpm(it seems there is need for some load on
the system to trigger the issue, but it seems to reliably trigger for
me)


So it seems reliably reproducible when compiling the kernel...



-- 
Chris Murphy