On 3/16/26 14:47, Breno Leitao wrote: > On Mon, Mar 16, 2026 at 12:55:13PM +0000, Lorenzo Stoakes (Oracle) wrote: >> On Mon, Mar 09, 2026 at 05:00:34AM -0700, Breno Leitao wrote: >>> Add a shell-based selftest that exercises the full set of THP sysfs >>> knobs: enabled (global and per-size anon), defrag, use_zero_page, >>> hpage_pmd_size, shmem_enabled (global and per-size), shrink_underused, >>> khugepaged/ tunables, and per-size stats files. >>> >>> Each writable knob is tested for valid writes, invalid-input rejection, >>> idempotent writes, and mode transitions where applicable. All original >>> values are saved before testing and restored afterwards. >>> >>> The test uses the kselftest KTAP framework (ktap_helpers.sh) for >>> structured TAP 13 output, making results parseable by the kselftest >>> harness. The test plan is printed at the end since the number of test >>> points is dynamic (depends on available hugepage sizes and sysfs files). >>> >>> This is particularly useful for validating the refactoring of >>> enabled_store() and anon_enabled_store() to use sysfs_match_string() >>> and the new change_enabled()/change_anon_orders() helpers. >>> >>> Signed-off-by: Breno Leitao <[email protected]> >> >> The test is broken locally for me, returning error code 127. >> >> I do appreciate the effort here, so I'm sorry to push back negatively, but I >> feel a bash script here is pretty janky, and frankly if any of these >> interfaces >> were as broken as this it'd be a major failure that would surely get picked >> up >> far sooner elsewhere. >> >> So while I think this might be useful as a local test for your sysfs >> interface >> changes, I don't think this is really suited to the mm selftests. > > That is totally fine. This test is what I have been using to test the > changes, and I decide to share it in case someone find it useful. > > Let's drop it.
Out of interest, to we know why the test is failing for Lorenzo? I agree that the test is a bit excessive, in particular when it comes to invalid/idempotent values etc. I could see some value for testing whether setting the modes keeps working, but also then I wonder if that is really something we'll be changing frequently (and that breaks easily). -- Cheers, David
