[PATCH liburing v2 0/1] test: add epoll test case

From: Stefano Garzarella
Date: Fri Jan 31 2020 - 09:29:52 EST


Hi Jens,
this is a v2 of the epoll test.

v1 -> v2:
- if IORING_FEAT_NODROP is not available, avoid to overflow the CQ
- add 2 new tests to test epoll with IORING_FEAT_NODROP
- cleanups

There are 4 sub-tests:
1. test_epoll
2. test_epoll_sqpoll
3. test_epoll_nodrop
4. test_epoll_sqpoll_nodrop

In the first 2 tests, I try to avoid to queue more requests than we have room
for in the CQ ring. These work fine, I have no faults.

In the tests 3 and 4, if IORING_FEAT_NODROP is supported, I try to submit as
much as I can until I get a -EBUSY, but they often fail in this way:
the submitter manages to submit everything, the receiver receives all the
submitted bytes, but the cleaner loses completion events (I also tried to put a
timeout to epoll_wait() in the cleaner to be sure that it is not related to the
patch that I send some weeks ago, but the situation doesn't change, it's like
there is still overflow in the CQ).

Next week I'll try to investigate better which is the problem.

I hope my test make sense, otherwise let me know what is wrong.

Anyway, when I was exploring the library, I had a doubt:
- in the __io_uring_get_cqe() should we call sys_io_uring_enter() also if
submit and wait_nr are zero, but IORING_SQ_NEED_WAKEUP is set in the
sq.kflags?

Thanks,
Stefano

Stefano Garzarella (1):
test: add epoll test case

.gitignore | 1 +
test/Makefile | 5 +-
test/epoll.c | 386 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 390 insertions(+), 2 deletions(-)
create mode 100644 test/epoll.c

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2.24.1