[RFC 00/11] io_uring specific task_work infra

[Pavel Begunkov <asml.silence@gmail.com>]

For experiments only. If proves to be useful would need to make it
nicer on the non-io_uring side.

0-10 save 1 spinlock/unlock_irq pair and 2 cmpxchg per batch. 11/11 in
general trades 1 per tw add spin_lock/unlock_irq and 2 per batch spinlocking
with 2 cmpxchg to 1 per tw add cmpxchg and 1 per batch cmpxchg.

Pavel Begunkov (11):
  io_uring: optimise io_req_task_work_add
  io_uringg: add io_should_fail_tw() helper
  io_uring: ban tw queue for exiting processes
  io_uring: don't take ctx refs in tctx_task_work()
  io_uring: add dummy io_uring_task_work_run()
  task_work: add helper for signalling a task
  io_uring: run io_uring task_works on TIF_NOTIFY_SIGNAL
  io_uring: wire io_uring specific task work
  io_uring: refactor io_run_task_work()
  io_uring: remove priority tw list
  io_uring: lock-free task_work stack

 fs/io-wq.c                |   1 +
 fs/io_uring.c             | 213 +++++++++++++++-----------------------
 include/linux/io_uring.h  |   4 +
 include/linux/task_work.h |   4 +
 kernel/entry/kvm.c        |   1 +
 kernel/signal.c           |   2 +
 kernel/task_work.c        |  33 +++---
 7 files changed, 115 insertions(+), 143 deletions(-)

-- 
2.36.0