tree 7de722898f1f55dacfed8d7fc938763ab931f7b5
parent af066f31eb3dac2a11516315d47a286a7b3b07df
author Pavel Begunkov <asml.silence@gmail.com> 1628510660 +0100
committer Jens Axboe <axboe@kernel.dk> 1629745686 -0600

io_uring: optimise putting task struct

We cache all the reference to task + tctx, so if io_put_task() is
called by the corresponding task itself, we can save on atomics and
return the refs right back into the cache.

It's beneficial for all inline completions, and also iopolling, when
polling and submissions are done by the same task, including
SQPOLL|IOPOLL.

Note: io_uring_cancel_generic() can return refs to the cache as well,
so those should be flushed in the loop for tctx_inflight() to work
right.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6fe9646b3cb70e46aca1f58426776e368c8926b3.1628471125.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>