On 5/9/19 4:40 PM, Logan Gunthorpe wrote: > > > On 2019-05-09 5:30 p.m., Theodore Ts'o wrote: >> On Thu, May 09, 2019 at 04:20:05PM -0600, Logan Gunthorpe wrote: >>> >>> The second item, arguably, does have significant overlap with kselftest. >>> Whether you are running short tests in a light weight UML environment or >>> higher level tests in an heavier VM the two could be using the same >>> framework for writing or defining in-kernel tests. It *may* also be valuable >>> for some people to be able to run all the UML tests in the heavy VM >>> environment along side other higher level tests. >>> >>> Looking at the selftests tree in the repo, we already have similar items to >>> what Kunit is adding as I described in point (2) above. kselftest_harness.h >>> contains macros like EXPECT_* and ASSERT_* with very similar intentions to >>> the new KUNIT_EXECPT_* and KUNIT_ASSERT_* macros. >>> >>> However, the number of users of this harness appears to be quite small. Most >>> of the code in the selftests tree seems to be a random mismash of scripts >>> and userspace code so it's not hard to see it as something completely >>> different from the new Kunit: >>> >>> $ git grep --files-with-matches kselftest_harness.h * >> >> To the extent that we can unify how tests are written, I agree that >> this would be a good thing. However, you should note that >> kselftest_harness.h is currently assums that it will be included in >> userspace programs. This is most obviously seen if you look closely >> at the functions defined in the header files which makes calls to >> fork(), abort() and fprintf(). > > Ah, yes. I obviously did not dig deep enough. Using kunit for > in-kernel tests and kselftest_harness for userspace tests seems like > a sensible line to draw to me. Trying to unify kernel and userspace > here sounds like it could be difficult so it's probably not worth > forcing the issue unless someone wants to do some really fancy work > to get it done. > > Based on some of the other commenters, I was under the impression > that kselftests had in-kernel tests but I'm not sure where or if they > exist. YES, kselftest has in-kernel tests. (Excuse the shouting...) Here is a likely list of them in the kernel source tree: $ grep module_init lib/test_*.c lib/test_bitfield.c:module_init(test_bitfields) lib/test_bitmap.c:module_init(test_bitmap_init); lib/test_bpf.c:module_init(test_bpf_init); lib/test_debug_virtual.c:module_init(test_debug_virtual_init); lib/test_firmware.c:module_init(test_firmware_init); lib/test_hash.c:module_init(test_hash_init); /* Does everything */ lib/test_hexdump.c:module_init(test_hexdump_init); lib/test_ida.c:module_init(ida_checks); lib/test_kasan.c:module_init(kmalloc_tests_init); lib/test_list_sort.c:module_init(list_sort_test); lib/test_memcat_p.c:module_init(test_memcat_p_init); lib/test_module.c:static int __init test_module_init(void) lib/test_module.c:module_init(test_module_init); lib/test_objagg.c:module_init(test_objagg_init); lib/test_overflow.c:static int __init test_module_init(void) lib/test_overflow.c:module_init(test_module_init); lib/test_parman.c:module_init(test_parman_init); lib/test_printf.c:module_init(test_printf_init); lib/test_rhashtable.c:module_init(test_rht_init); lib/test_siphash.c:module_init(siphash_test_init); lib/test_sort.c:module_init(test_sort_init); lib/test_stackinit.c:module_init(test_stackinit_init); lib/test_static_key_base.c:module_init(test_static_key_base_init); lib/test_static_keys.c:module_init(test_static_key_init); lib/test_string.c:module_init(string_selftest_init); lib/test_ubsan.c:module_init(test_ubsan_init); lib/test_user_copy.c:module_init(test_user_copy_init); lib/test_uuid.c:module_init(test_uuid_init); lib/test_vmalloc.c:module_init(vmalloc_test_init) lib/test_xarray.c:module_init(xarray_checks); > If they do exists, it seems like it would make sense to > convert those to kunit and have Kunit tests run-able in a VM or > baremetal instance. They already run in a VM. They already run on bare metal. They already run in UML. This is not to say that KUnit does not make sense. But I'm still trying to get a better description of the KUnit features (and there are some). -Frank
