[RFC 0/1] KVM: selftests: rseq_test: use vdso_getcpu() instead of syscall()

[Robert Hoo <robert.hu@linux.intel.com>]

Recently, our QA often meet the test assert failure in KVM selftest rseq_test.
e.g.
==== Test Assertion Failure ====
  rseq_test.c:273: i > (NR_TASK_MIGRATIONS / 2)
  pid=391366 tid=391366 errno=4 - Interrupted system call
     1	0x00000000004027dd: main at rseq_test.c:272
     2	0x00007f7fc383ad84: ?? ??:0
     3	0x000000000040286d: _start at ??:?
  Only performed 32083 KVM_RUNs, task stalled too much?

Though this is not a bug [1], passing this assert means the race condition
can be more hit, which is the original purpose of this test case design.

[1] https://lore.kernel.org/kvm/YvwYxeE4vc%2FSrbil@google.com/

Robert Hoo (1):
  KVM: selftests: rseq_test: use vdso_getcpu() instead of syscall()

 tools/testing/selftests/kvm/rseq_test.c | 32 ++++++++++++++++++-------
 1 file changed, 24 insertions(+), 8 deletions(-)

-- 
2.31.1