Hi, I've been trying the hmm_tests as of today's commit: a185a0995518 ("Merge tag 'linux-kselftest-kunit-6.1-rc1-2' ...) and run into several issues that seemed worth reporting. First, it seems the FIXTURE_TEARDOWN(hmm) in tools/testing/selftests/vm/hmm-tests.c using ASSERT_EQ(ret, 0); can run into an infinite loop of reporting the assertion failure. Dunno if it's a kselftests issue or it's a bug to use asserts in teardown. I hacked it up like this locally to proceed: --- a/tools/testing/selftests/vm/hmm-tests.c +++ b/tools/testing/selftests/vm/hmm-tests.c @@ -154,6 +154,11 @@ FIXTURE_TEARDOWN(hmm) { int ret = close(self->fd); + if (ret != 0) { + fprintf(stderr, "close returned (%d) fd is (%d)\n", ret,self->fd); + exit(1); + } + ASSERT_EQ(ret, 0); self->fd = -1; } Next, there are some tests that fail (and thus also trigger the issue above) # RUN hmm.hmm_device_private.exclusive ... # hmm-tests.c:1702:exclusive:Expected ret (-16) == 0 (0) close returned (-1) fd is (3) # exclusive: Test failed at step #1 # FAIL hmm.hmm_device_private.exclusive not ok 20 hmm.hmm_device_private.exclusive # RUN hmm.hmm_device_private.exclusive_mprotect ... # hmm-tests.c:1756:exclusive_mprotect:Expected ret (-16) == 0 (0) close returned (-1) fd is (3) # exclusive_mprotect: Test failed at step #1 # FAIL hmm.hmm_device_private.exclusive_mprotect not ok 21 hmm.hmm_device_private.exclusive_mprotect # RUN hmm.hmm_device_private.exclusive_cow ... # hmm-tests.c:1809:exclusive_cow:Expected ret (-16) == 0 (0) close returned (-1) fd is (3) # exclusive_cow: Test failed at step #1 # FAIL hmm.hmm_device_private.exclusive_cow not ok 22 hmm.hmm_device_private.exclusive_cow I'll try to check more closely but maybe if you can reproduce it too, you'll have more idea what's going on. The next thing is more of a question/documentation suggestion. Tons of tests fail like this: ok 24 hmm.hmm_device_private.hmm_cow_in_device # RUN hmm.hmm_device_coherent.open_close ... could not open hmm dmirror driver (/dev/hmm_dmirror2) # SKIP DEVICE_COHERENT not available # OK hmm.hmm_device_coherent.open_close I assume this is because I run "test_hmm.sh smoke" without the SPM parameters. The help message doesn't say much about what to specify there for <spm_addr_dev0> <spm_addr_dev1>. Do these tests need a particular hardware? (unlike the rest?) Maybe it could be clarified. Last thing, I noticed all these DEVICE_COHERENT tests ultimately count as OK, not SKIPPED, which would probably be more appropriate? # FAILED: 51 / 54 tests passed. # Totals: pass:50 fail:3 xfail:0 xpass:0 skip:1 error:0 (the skip:1 is due to test 9 "# SKIP Huge page could not be allocated" which is probably a misconfiguration on my part so I don't report that as an issue) Thanks, Vlastimil