FYI, we noticed the following commit (built with gcc-7):
commit: 47704eaeb47ea6636650d3637368f5bbf79a6f65 ("shmem: Convert shmem_add_to_page_cache to XArray")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
in testcase: kernel_selftests
with following parameters:
group: kselftests-03
test-description: The kernel contains a set of "self tests" under the tools/testing/selftests/ directory. These are intended to be small unit tests to exercise individual code paths in the kernel.
test-url: https://www.kernel.org/doc/Documentation/kselftest.txt
on test machine: qemu-system-x86_64 -enable-kvm -cpu host -smp 2 -m 4G
caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
-------------------------
running userfaultfd_shmem
-------------------------
nr_pages: 32768, nr_pages_per_cpu: 16384
bounces: 31, mode: rnd racing ver poll, UFFDIO_COPY retry error -2
[FAIL]
To reproduce:
git clone https://github.com/intel/lkp-tests.git
cd lkp-tests
bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email
Thanks,
Xiaolong