Re: [PATCH v9 0/6] selftests/mm: separate GUP microbenchmarking from functional testing

On 9/4/26 6:06 PM, Sarthak Sharma wrote:

gup_test.c currently serves two separate purposes: benchmarking
(GUP_FAST_BENCHMARK, PIN_FAST_BENCHMARK and PIN_LONGTERM_BENCHMARK) and
functional testing (GUP_BASIC_TEST, PIN_BASIC_TEST and
DUMP_USER_PAGES_TEST). Keeping both in one program makes the functional
tests harder to run and report individually, while run_vmtests.sh has to
invoke the program repeatedly with different options.

Separate these roles into tools/mm/gup_bench for benchmarking and
tools/testing/selftests/mm/gup for functional testing. Move the shared
file and hugepage helpers to tools/lib/mm/ so both programs can use them
without duplicating the implementation.

I went through Sashiko's review on this patchset [1] and wanted to
address the concerns it raises.

Both the concerns here are false positives, as it assumes that
FIXTURE_TEARDOWN() will run if FIXTURE_SETUP() fails. But in the
kselftest harness, we initialize the variable no_teardown to true before
calling FIXTURE_SETUP() and make it false only when FIXTURE_SETUP()
completes successfully. So, if ASSERT_*() fails in FIXTURE_SETUP(),
FIXTURE_TEARDOWN() won't run. Therefore neither stdin will be closed nor
self->gup_fd will be closed twice.

[1]
https://sashiko.dev/#/patchset/20260904123631.198697-1-sarthak.sharma%40arm.com