On 7/27/24 12:35 AM, Shuah Khan wrote: > On 7/15/24 04:09, Muhammad Usama Anjum wrote: >> Hi Kees and All, >> >> There are several tests in kselftest subsystem which load modules to tests >> the internals of the kernel. Most of these test modules are just loaded by >> the kselftest, their status isn't read and reported to the user logs. Hence >> they don't provide benefit of executing those tests. >> >> I've found patches from Kees where he has been converting such kselftests >> to kunit tests [1]. The probable motivation is to move tests output of >> kselftest subsystem which only triggers tests without correctly reporting >> the results. On the other hand, kunit is there to test the kernel's >> internal functions which can't be done by userspace. >> >> Kselftest: Test user facing APIs from userspace >> Kunit: Test kernel's internal functions from kernelspace >> >> This brings me to conclusion that kselftest which are loading modules to >> test kernelspace should be converted to kunit tests. I've noted several >> such kselftests. >> >> This is just my understanding. Please mention if I'm correct above or more >> reasons to support kselftest test modules transformation into kunit test. >> >> [1] https://lore.kernel.org/all/20221018082824.never.845-kees@xxxxxxxxxx/ >> > > Please make sure you aren't taking away the ability to run these tests during > boot. The kunit tests are usually run at boot time. They can be run later as well. So I'm not trying to remove any functionality. Rather adding a way where failures would actually be detected. > It doesn't make sense to convert every single test especially when it > is intended to be run during boot without dependencies - not as a kunit test > but a regression test during boot. I started investigating when these lib kselftests were just loading the test module without checking if test actually passed/failed (which proves that this type of kselftests can never detect regression as it doesn't process the results). It was strange. Hence I found out the conversion of such kselftests to kunit tests done by Kees and started this thread for discussion before doing actual work and sending patches. > > bitmap is one example - pay attention to the config help test - bitmap > one clearly states it runs regression testing during boot. Any test that > says that isn't a candidate for conversion. Please can you explain what do you mean by bitmap testing during boot? As far as I understand, the kselftests are usespace tests and are run after kernel has booted completely and userspace has started. It cannot be regarded as testing during boot. > > I am going to nack any such conversions. > > thanks, > -- Shuah > -- BR, Muhammad Usama Anjum
