[0/4] Cache tctx cancelation state in the ctx

Message

Jens Axboe Feb. 17, 2023, 3:55 p.m. UTC

Hi,

One of the more expensive parts of io_req_local_work_add() is that it
has to pull in the remote task tctx to check for the very unlikely event
that we are in a cancelation state.

Cache the cancelation state in each ctx instead. This makes the marking
of cancelation (and clearing) a bit more expensive, but those are very
slow path operations. The upside is that io_req_local_work_add()
becomes a lot cheaper, which is what we care about.