[PATCH v4 0/3] interrupt disconnect/error event handling

[Kevin Traynor <ktraynor@redhat.com>]

These patches are to fix some issues with epoll event handling for
EPOLLERR/EPOLLRDHUP/EPOLLHUP.

1/3: handles these disconnect/error events for interrupts that are read
in eal

2/3: provides an API for interrupt callbacks to get the interrupt events
for the active interrupt

3/3: deal with the observed issue as reported in
https://bugs.dpdk.org/show_bug.cgi?id=1873 where mlx5 devx interrupts
cause a busy-loop and 100% CPU of dpdk-intr thread.

v4:
Updated to allow for case where devx interrupt handler may handle
multiple completions during one interrupt call, leading to no data being
read in a subsequent call as flagged by Slava.

- 1/3 No change
- 2/3 New API rte_intr_active_events() to get interrupt events
- 3/3 Use new API in mlx5 devx interrupt handler to detect if
  disconnect/error events and if so unregister the callback

v3:
- 1/2 and 2/2 fix some coding nits (Stephen/AI/David)
- 2/2 Make log level consistant (David)

v2:
- Only handle disconnect/error epoll events when the read is done in eal
  interrupt code. This is to allow interrupt handlers like virtio deal
  with disconnects in an appropriate
- Detect if not data is read in the mlx dex interrupt and if so unregister
  the callback

Kevin Traynor (3):
  eal/linux: handle interrupt epoll events
  eal/interrupt: add interrupt event info
  net/mlx5: check devx disconnect/error interrupt events

 drivers/net/mlx5/linux/mlx5_ethdev_os.c |  20 +++++
 lib/eal/freebsd/eal_interrupts.c        |   7 ++
 lib/eal/include/rte_interrupts.h        |  23 ++++++
 lib/eal/linux/eal_interrupts.c          | 103 +++++++++++++++++-------
 lib/eal/windows/eal_interrupts.c        |   7 ++
 5 files changed, 133 insertions(+), 27 deletions(-)

-- 
2.53.0