tree de9be151f1bd21d306e7c779a27d9d99c111ac70
parent 87e5e6dab6c2a21fab2620f37786276d202e2ce0
author Jens Axboe <axboe@kernel.dk> 1557949987 -0600
committer Jens Axboe <axboe@kernel.dk> 1559338203 -0600

io_uring: punt short reads to async context

We can encounter a short read when we're doing buffered reads and the
data is partially cached. Right now we just return the short read, but
that forces the application to read that CQE, then issue another SQE
to finish the read. That read will not be cached, and hence will result
in an async punt.

It's more efficient to do that async punt from within the kernel, as
that will the not need two round trips more to the kernel.

Signed-off-by: Jens Axboe <axboe@kernel.dk>