kernel/linux.git/io_uring/notif.h, branch linux-6.0.y

io_uring/net: simplify zerocopy send user API

2022-09-01T15:13:33+00:00

Following user feedback, this patch simplifies zerocopy send API. One of the main complaints is that the current API is difficult with the userspace managing notification slots, and then send retries with error handling make it even worse. Instead of keeping notification slots change it to the per-request notifications model, which posts both completion and notification CQEs for each request when any data has been sent, and only one CQE if it fails. All notification CQEs will have IORING_CQE_F_NOTIF set and IORING_CQE_F_MORE in completion CQEs indicates whether to wait a notification or not. IOSQE_CQE_SKIP_SUCCESS is disallowed with zerocopy sends for now. This is less flexible, but greatly simplifies the user API and also the kernel implementation. We reuse notif helpers in this patch, but in the future there won't be need for keeping two requests. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/95287640ab98fc9417370afb16e310677c63e6ce.1662027856.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/notif: remove notif registration

2022-09-01T15:13:33+00:00

We're going to remove the userspace exposed zerocopy notification API, remove notification registration. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/6ff00b97be99869c386958a990593c9c31cf105b.1662027856.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/notif: raise limit on notification slots

2022-08-16T03:34:00+00:00

1024 notification slots is rather an arbitrary value, raise it up, everything is accounted to memcg. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/eb78a0a5f2fa5941f8e845cdae5fb399bf7ba0be.1660566179.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: make io_kiocb_to_cmd() typesafe

2022-08-12T23:01:00+00:00

We need to make sure (at build time) that struct io_cmd_data is not casted to a structure that's larger. Signed-off-by: Stefan Metzmacher Link: https://lore.kernel.org/r/c024cdf25ae19fc0319d4180e2298bade8ed17b8.1660201408.git.metze@samba.org Signed-off-by: Jens Axboe

io_uring: notification completion optimisation

2022-07-27T14:50:50+00:00

We want to use all optimisations that we have for io_uring requests like completion batching, memory caching and more but for zc notifications. Fortunately, notification perfectly fit the request model so we can overlay them onto struct io_kiocb and use all the infratructure. Most of the fields of struct io_notif natively fits into io_kiocb, so we replace struct io_notif with struct io_kiocb carrying struct io_notif_data in the cmd cache line. Then we adapt io_alloc_notif() to use io_alloc_req()/io_alloc_req_refill(), and kill leftovers of hand coded caching. __io_notif_complete_tw() is converted to use io_uring's tw infra. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/9e010125175e80baf51f0ca63bdc7cc6a4a9fa56.1658913593.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/net: make page accounting more consistent

2022-07-25T15:48:25+00:00

Make network page accounting more consistent with how buffer registration is working, i.e. account all memory to ctx->user. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/4aacfe64bbb81b27f9ecf5d5c219c69a07e5aa56.1658742118.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/net: improve io_get_notif_slot types

2022-07-25T15:47:45+00:00

Don't use signed int for slot indexing. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/e4d15aefebb5e55729dd9b5ec01ab16b70033343.1658742118.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: flush notifiers after sendzc

2022-07-25T00:41:07+00:00

Allow to flush notifiers as a part of sendzc request by setting IORING_SENDZC_FLUSH flag. When the sendzc request succeedes it will flush the used [active] notifier. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/e0b4d9a6797e2fd6092824fe42953db7a519bbc8.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: add notification slot registration

2022-07-25T00:41:07+00:00

Let the userspace to register and unregister notification slots. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/a0aa8161fe3ebb2a4cc6e5dbd0cffb96e6881cf5.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: add rsrc referencing for notifiers

2022-07-25T00:41:06+00:00

In preparation to zerocopy sends with fixed buffers make notifiers to reference the rsrc node to protect the used fixed buffers. We can't just grab it for a send request as notifiers can likely outlive requests that used it. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/3cd7a01d26837945b6982fa9cf15a63230f2ed4f.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe