[PATCH for-next 0/7] cqe posting cleanups

Pavel Begunkov
2022-06-19T11:26:45Z

Apart from this patches removing some implicit assumptions, which we
had problems with before, and making code cleaner, they and especially
6-7 are also needed to push for synchronisation optimisations later, lile
[1] or removing spinlocking with SINGLE_ISSUER.

The downside is that we add additional lock/unlock into eventfd path,
but I don't think we care about it.

The series also exposes a minor issue with cancellations, which for some
reason calls io_kill_timeouts() and io_poll_remove_all() too many times on
task exit. That makes poll-cancel to timeout on sigalarm, though usually
is fine if given 3-5 sec instead of 1. We'll investigate it later.

[1] https://github.com/isilence/linux/commit/6224f58bf7b542e6aed1eed44ee6bd5b5f706437

Pavel Begunkov (7):
io_uring: remove extra io_commit_cqring()
io_uring: reshuffle io_uring/io_uring.h
io_uring: move io_eventfd_signal()
io_uring: hide eventfd assumptions in evenfd paths
io_uring: remove ->flush_cqes optimisation
io_uring: introduce locking helpers for CQE posting
io_uring: add io_commit_cqring_flush()

include/linux/io_uring_types.h | 2 +
io_uring/io_uring.c | 144 ++++++++++++++++-----------------
io_uring/io_uring.h | 108 ++++++++++++++-----------
io_uring/rw.c | 5 +-
io_uring/timeout.c | 7 +-
5 files changed, 133 insertions(+), 133 deletions(-)

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2.36.1