I think this might be the same problem I'm running in to, which only seems to happen on 32-bit kernels, starting with commit f43dc4dc3eff0. Problem is still present in 6.13. Easy repro steps are as follows: hash mkfs.xfs || apt install -y xfsprogs rm -f xfsimg.bin truncate -s 6G xfsimg.bin # I can reproduce this with an xfs image, but not with ext4 mkfs.xfs xfsimg.bin mkdir -p xfs mount xfsimg.bin xfs truncate -s 5G xfs/diskimg.bin mkfs.ext4 xfs/diskimg.bin # this can probably be any fs type, it happens with fat too mkdir -p mnt mount xfs/diskimg.bin mnt dd if=/dev/zero of=mnt/file.bin bs=1M of=mnt/file.bin bs=1M The above almost immediately prints a warning to the kernel log, after which there is a kworker thread hogging the CPU
