On Sat, Feb 8, 2025 at 12:53 PM Yury Norov <yury.norov@xxxxxxxxx> wrote: > > [...] > > Take over means that you'd at least add the Co-developed-by tag. I didn't use their code - the thing being "taken over" is the work of having these debates with the maintainers. > [...] > > KUNIT is disabled in defconfig, at least on x86_64. It is also disabled > on my Ubuntu 24.04 machine. If I take your patches, I'll be unable to > boot-test bitmaps. Even worse, I'll be unable to build the standalone > test from sources as a module and load it later. > > Or I misunderstand it, and there's a way to build some particular KUNIT > test without enabling KUNIT in config and/or re-compiling the whole kernel? > Please teach me, if so > > Unless you give me a way to build and run the test in true > production environment, I'm not going with KUNITs. Sorry. This is a question for David -- I don't know if this is possible. > [...] > > This is my evidence: sometimes people report performance or whatever > issues on their systems, suspecting bitmaps guilty. I ask them to run > the bitmap or find_bit test to narrow the problem. Sometimes I need to > test a hardware I have no access to, and I have to (kindly!) ask people > to build a small test and run it. I don't want to ask them to rebuild > the whole kernel, or even to build something else. > > https://lore.kernel.org/all/YuWk3titnOiQACzC@yury-laptop/ This is compelling evidence, and it was not previously raised. Thank you. I notice that two things are true about the performance test part of test_bitmap.c: - It's a minority of the code in the file (48 lines out of 1462). - There are no assertions in it. Do you also find value in running the testing portion on other people's machines, to which you don't have access? > [...] > > Nice summary for the discussion. Unfortunately you missed my concerns. > Which are: > > Pros: > - Now we switch to KUNITs because KUNITs are so good > > Cons: > - Wipes git history; I was very careful to minimize churn, and the result is 249 lines on which I'd now own the blame (228 with `-w`). Still, it's a valid con. > - Bloats the test's source code; The test is 74 lines shorter after this series. > - Adds dependencies; > - Doesn't run on most popular distros and defconfig; Yep, I understand your concerns much better now - and I'm grateful for your having taken the time to explain and show receipts. Still, I wonder if we can get the best of both worlds - either by finding what you need in KUnit, or by moving the testing bit to KUnit and keeping the performance bit where it is. Thanks. Tamir
