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2022-09-21io_uring: signal registered eventfd to process deferred task workDylan Yudaken
Some workloads rely on a registered eventfd (via io_uring_register_eventfd(3)) in order to wake up and process the io_uring. In the case of a ring setup with IORING_SETUP_DEFER_TASKRUN, that eventfd also needs to be signalled when there are tasks to run. This changes an old behaviour which assumed 1 eventfd signal implied at least 1 CQE, however only when this new flag is set (and so old users will not notice). This should be expected with the IORING_SETUP_DEFER_TASKRUN flag as it is not guaranteed that every task will result in a CQE. Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220830125013.570060-7-dylany@fb.com [axboe: fold in call_rcu() serialization fix] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21io_uring: move io_eventfd_putDylan Yudaken
Non functional change: move this function above io_eventfd_signal so it can be used from there Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220830125013.570060-6-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21io_uring: add IORING_SETUP_DEFER_TASKRUNDylan Yudaken
Allow deferring async tasks until the user calls io_uring_enter(2) with the IORING_ENTER_GETEVENTS flag. Enable this mode with a flag at io_uring_setup time. This functionality requires that the later io_uring_enter will be called from the same submission task, and therefore restrict this flag to work only when IORING_SETUP_SINGLE_ISSUER is also set. Being able to hand pick when tasks are run prevents the problem where there is current work to be done, however task work runs anyway. For example, a common workload would obtain a batch of CQEs, and process each one. Interrupting this to additional taskwork would add latency but not gain anything. If instead task work is deferred to just before more CQEs are obtained then no additional latency is added. The way this is implemented is by trying to keep task work local to a io_ring_ctx, rather than to the submission task. This is required, as the application will want to wake up only a single io_ring_ctx at a time to process work, and so the lists of work have to be kept separate. This has some other benefits like not having to check the task continually in handle_tw_list (and potentially unlocking/locking those), and reducing locks in the submit & process completions path. There are networking cases where using this option can reduce request latency by 50%. For example a contrived example using [1] where the client sends 2k data and receives the same data back while doing some system calls (to trigger task work) shows this reduction. The reason ends up being that if sending responses is delayed by processing task work, then the client side sits idle. Whereas reordering the sends first means that the client runs it's workload in parallel with the local task work. [1]: Using https://github.com/DylanZA/netbench/tree/defer_run Client: ./netbench --client_only 1 --control_port 10000 --host <host> --tx "epoll --threads 16 --per_thread 1 --size 2048 --resp 2048 --workload 1000" Server: ./netbench --server_only 1 --control_port 10000 --rx "io_uring --defer_taskrun 0 --workload 100" --rx "io_uring --defer_taskrun 1 --workload 100" Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220830125013.570060-5-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21io_uring: do not run task work at the start of io_uring_enterDylan Yudaken
This is not needed, and it is normally better to wait for task work until after submissions. This will allow greater batching if either work arrives in the meanwhile, or if the submissions cause task work to be queued up. For SQPOLL this also no longer runs task work, but this is handled inside the SQPOLL loop anyway. For IOPOLL io_iopoll_check will run task work anyway And otherwise io_cqring_wait will run task work Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220830125013.570060-4-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21io_uring: introduce io_has_workDylan Yudaken
This will be used later to know if the ring has outstanding work. Right now just if there is overflow CQEs to copy to the main CQE ring, but later will include deferred tasks Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220830125013.570060-3-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21io_uring: remove unnecessary variableDylan Yudaken
'running' is set once and read once, so can easily just remove it Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220830125013.570060-2-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-07io_uring: recycle kbuf recycle on tw requeuePavel Begunkov
When we queue a request via tw for execution it's not going to be executed immediately, so when io_queue_async() hits IO_APOLL_READY and queues a tw but doesn't try to recycle/consume the buffer some other request may try to use the the buffer. Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/a19bc9e211e3184215a58e129b62f440180e9212.1662480490.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-01io_uring/net: simplify zerocopy send user APIPavel Begunkov
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 <asml.silence@gmail.com> Link: https://lore.kernel.org/r/95287640ab98fc9417370afb16e310677c63e6ce.1662027856.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-01io_uring/notif: remove notif registrationPavel Begunkov
We're going to remove the userspace exposed zerocopy notification API, remove notification registration. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/6ff00b97be99869c386958a990593c9c31cf105b.1662027856.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-24io_uring: conditional ->async_data allocationPavel Begunkov
There are opcodes that need ->async_data only in some cases and allocation it unconditionally may hurt performance. Add an option to opdef to make move the allocation part from the core io_uring to opcode specific code. Note, we can't just set opdef->async_size to zero because there are other helpers that rely on it, e.g. io_alloc_async_data(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9dc62be9e88dd0ed63c48365340e8922d2498293.1661342812.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-12io_uring: add missing BUILD_BUG_ON() checks for new io_uring_sqe fieldsStefan Metzmacher
Signed-off-by: Stefan Metzmacher <metze@samba.org> Link: https://lore.kernel.org/r/ffcaf8dc4778db4af673822df60dbda6efdd3065.1660201408.git.metze@samba.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-27io_uring: notification completion optimisationPavel Begunkov
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 <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9e010125175e80baf51f0ca63bdc7cc6a4a9fa56.1658913593.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-27io_uring: export req alloc from corePavel Begunkov
We want to do request allocation out of the core io_uring code, make the allocation functions public for other io_uring parts. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0314fedd3a02a514210ba42d4720332538c65956.1658913593.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: flush notifiers after sendzcPavel Begunkov
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 <asml.silence@gmail.com> Link: https://lore.kernel.org/r/e0b4d9a6797e2fd6092824fe42953db7a519bbc8.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: add notification slot registrationPavel Begunkov
Let the userspace to register and unregister notification slots. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/a0aa8161fe3ebb2a4cc6e5dbd0cffb96e6881cf5.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: cache struct io_notifPavel Begunkov
kmalloc'ing struct io_notif is too expensive when done frequently, cache them as many other resources in io_uring. Keep two list, the first one is from where we're getting notifiers, it's protected by ->uring_lock. The second is protected by ->completion_lock, to which we queue released notifiers. Then we splice one list into another when needed. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9dec18f7fcbab9f4bd40b96e5ae158b119945230.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: add zc notification infrastructurePavel Begunkov
Add internal part of send zerocopy notifications. There are two main structures, the first one is struct io_notif, which carries inside struct ubuf_info and maps 1:1 to it. io_uring will be binding a number of zerocopy send requests to it and ask to complete (aka flush) it. When flushed and all attached requests and skbs complete, it'll generate one and only one CQE. There are intended to be passed into the network layer as struct msghdr::msg_ubuf. The second concept is notification slots. The userspace will be able to register an array of slots and subsequently addressing them by the index in the array. Slots are independent of each other. Each slot can have only one notifier at a time (called active notifier) but many notifiers during the lifetime. When active, a notifier not going to post any completion but the userspace can attach requests to it by specifying the corresponding slot while issueing send zc requests. Eventually, the userspace will want to "flush" the notifier losing any way to attach new requests to it, however it can use the next atomatically added notifier of this slot or of any other slot. When the network layer is done with all enqueued skbs attached to a notifier and doesn't need the specified in them user data, the flushed notifier will post a CQE. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3ecf54c31a85762bf679b0a432c9f43ecf7e61cc.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: export io_put_task()Pavel Begunkov
Make io_put_task() available to non-core parts of io_uring, we'll need it for notification infrastructure. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3686807d4c03b72e389947b0e8692d4d44334ef0.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: ensure REQ_F_ISREG is set async offloadJens Axboe
If we're offloading requests directly to io-wq because IOSQE_ASYNC was set in the sqe, we can miss hashing writes appropriately because we haven't set REQ_F_ISREG yet. This can cause a performance regression with buffered writes, as io-wq then no longer correctly serializes writes to that file. Ensure that we set the flags in io_prep_async_work(), which will cause the io-wq work item to be hashed appropriately. Fixes: 584b0180f0f4 ("io_uring: move read/write file prep state into actual opcode handler") Link: https://lore.kernel.org/io-uring/20220608080054.GB22428@xsang-OptiPlex-9020/ Reported-by: kernel test robot <oliver.sang@intel.com> Tested-by: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: Don't require reinitable percpu_refMichal Koutný
The commit 8bb649ee1da3 ("io_uring: remove ring quiesce for io_uring_register") removed the worklow relying on reinit/resurrection of the percpu_ref, hence, initialization with that requested is a relic. This is based on code review, this causes no real bug (and theoretically can't). Technically it's a revert of commit 214828962dea ("io_uring: initialize percpu refcounters using PERCU_REF_ALLOW_REINIT") but since the flag omission is now justified, I'm not making this a revert. Fixes: 8bb649ee1da3 ("io_uring: remove ring quiesce for io_uring_register") Signed-off-by: Michal Koutný <mkoutny@suse.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: add netmsg cacheJens Axboe
For recvmsg/sendmsg, if they don't complete inline, we currently need to allocate a struct io_async_msghdr for each request. This is a somewhat large struct. Hook up sendmsg/recvmsg to use the io_alloc_cache. This reduces the alloc + free overhead considerably, yielding 4-5% of extra performance running netbench. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: impose max limit on apoll cacheJens Axboe
Caches like this tend to grow to the peak size, and then never get any smaller. Impose a max limit on the size, to prevent it from growing too big. A somewhat randomly chosen 512 is the max size we'll allow the cache to get. If a batch of frees come in and would bring it over that, we simply start kfree'ing the surplus. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: add abstraction around apoll cacheJens Axboe
In preparation for adding limits, and one more user, abstract out the core bits of the allocation+free cache. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: move apoll cache to poll.cJens Axboe
This is where it's used, move the flush handler in there. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: only trace one of complete or overflowDylan Yudaken
In overflow we see a duplcate line in the trace, and in some cases 3 lines (if initial io_post_aux_cqe fails). Instead just trace once for each CQE Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220630091231.1456789-13-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: add allow_overflow to io_post_aux_cqeDylan Yudaken
Some use cases of io_post_aux_cqe would not want to overflow as is, but might want to change the flags/result. For example multishot receive requires in order CQE, and so if there is an overflow it would need to stop receiving until the overflow is taken care of. Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220630091231.1456789-8-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: let to set a range for file slot allocationPavel Begunkov
From recently io_uring provides an option to allocate a file index for operation registering fixed files. However, it's utterly unusable with mixed approaches when for a part of files the userspace knows better where to place it, as it may race and users don't have any sane way to pick a slot and hoping it will not be taken. Let the userspace to register a range of fixed file slots in which the auto-allocation happens. The use case is splittting the fixed table in two parts, where on of them is used for auto-allocation and another for slot-specified operations. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/66ab0394e436f38437cf7c44676e1920d09687ad.1656154403.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: remove ctx->refs pinning on enterPavel Begunkov
io_uring_enter() takes ctx->refs, which was previously preventing racing with register quiesce. However, as register now doesn't touch the refs, we can freely kill extra ctx pinning and rely on the fact that we're holding a file reference preventing the ring from being destroyed. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/a11c57ad33a1be53541fce90669c1b79cf4d8940.1656153286.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: don't check file ops of registered ringsPavel Begunkov
Registered rings are per definitions io_uring files, so we don't need to additionally verify them. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/425cd64fd885b8e329a46c205ee811987691baaf.1656153286.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: remove extra TIF_NOTIFY_SIGNAL checkPavel Begunkov
io_run_task_work() accounts for TIF_NOTIFY_SIGNAL, so no need to have an second check in io_run_task_work_sig(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/52ce41a592ad904511697f432141e5690fd4b968.1656153285.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: fuse fallback_node and normal tw nodePavel Begunkov
Now as both normal and fallback paths use llist, just keep one node head in struct io_task_work and kill off ->fallback_node. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/d04ebde409f7b162fe247b361b4486b193293e46.1656153285.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: add sync cancelation API through io_uring_register()Jens Axboe
The io_uring cancelation API is async, like any other API that we expose there. For the case of finding a request to cancel, or not finding one, it is fully sync in that when submission returns, the CQE for both the cancelation request and the targeted request have been posted to the CQ ring. However, if the targeted work is being executed by io-wq, the API can only start the act of canceling it. This makes it difficult to use in some circumstances, as the caller then has to wait for the CQEs to come in and match on the same cancelation data there. Provide a IORING_REGISTER_SYNC_CANCEL command for io_uring_register() that does sync cancelations, always. For the io-wq case, it'll wait for the cancelation to come in before returning. The only expected returns from this API is: 0 Request found and canceled fine. > 0 Requests found and canceled. Only happens if asked to cancel multiple requests, and if the work wasn't in progress. -ENOENT Request not found. -ETIME A timeout on the operation was requested, but the timeout expired before we could cancel. and we won't get -EALREADY via this API. If the timeout value passed in is -1 (tv_sec and tv_nsec), then that means that no timeout is requested. Otherwise, the timespec passed in is the amount of time the sync cancel will wait for a successful cancelation. Link: https://github.com/axboe/liburing/discussions/608 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: trace task_work_runDylan Yudaken
trace task_work_run to help provide stats on how often task work is run and what batch sizes are coming through. Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220622134028.2013417-9-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: batch task_workDylan Yudaken
Batching task work up is an important performance optimisation, as task_work_add is expensive. In order to keep the semantics replace the task_list with a fake node while processing the old list, and then do a cmpxchg at the end to see if there is more work. Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220622134028.2013417-6-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: introduce llist helpersDylan Yudaken
Introduce helpers to atomically switch llist. Will later move this into common code Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220622134028.2013417-5-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: lockless task listDylan Yudaken
With networking use cases we see contention on the spinlock used to protect the task_list when multiple threads try and add completions at once. Instead we can use a lockless list, and assume that the first caller to add to the list is responsible for kicking off task work. Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220622134028.2013417-4-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: remove __io_req_task_work_addDylan Yudaken
this is no longer needed as there is only one caller Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220622134028.2013417-3-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: remove priority tw list optimisationDylan Yudaken
This optimisation has some built in assumptions that make it easy to introduce bugs. It also does not have clear wins that make it worth keeping. Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220622134028.2013417-2-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: consistent naming for inline completionPavel Begunkov
Improve naming of the inline/deferred completion helper so it's consistent with it's *_post counterpart. Add some comments and extra lockdeps to ensure the locking is done right. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/797c619943dac06529e9d3fcb16e4c3cde6ad1a3.1655684496.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: add io_commit_cqring_flush()Pavel Begunkov
Since __io_commit_cqring_flush users moved to different files, introduce io_commit_cqring_flush() helper and encapsulate all flags testing details inside. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0da03887435dd9869ffe46dcd3962bf104afcca3.1655684496.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: introduce locking helpers for CQE postingPavel Begunkov
spin_lock(&ctx->completion_lock); /* post CQEs */ io_commit_cqring(ctx); spin_unlock(&ctx->completion_lock); io_cqring_ev_posted(ctx); We have many places repeating this sequence, and the three function unlock section is not perfect from the maintainance perspective and also makes it harder to add new locking/sync trick. Introduce two helpers. io_cq_lock(), which is simple and only grabs ->completion_lock, and io_cq_unlock_post() encapsulating the three call section. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/fe0c682bf7f7b55d9be55b0d034be9c1949277dc.1655684496.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: hide eventfd assumptions in eventfd pathsPavel Begunkov
Some io_uring-eventfd users assume that there won't be spurious wakeups. That assumption has to be honoured by all io_cqring_ev_posted() callers, which is inconvenient and from time to time leads to problems but should be maintained to not break the userspace. Instead of making the callers track whether a CQE was posted or not, hide it inside io_eventfd_signal(). It saves ->cached_cq_tail it saw last time and triggers the eventfd only when ->cached_cq_tail changed since then. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0ffc66bae37a2513080b601e4370e147faaa72c5.1655684496.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: fix multi ctx cancellationPavel Begunkov
io_uring_try_cancel_requests() loops until there is nothing left to do with the ring, however there might be several rings and they might have dependencies between them, e.g. via poll requests. Instead of cancelling rings one by one, try to cancel them all and only then loop over if we still potenially some work to do. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/8d491fe02d8ac4c77ff38061cf86b9a827e8845c.1655684496.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: remove ->flush_cqes optimisationPavel Begunkov
It's not clear how widely used IOSQE_CQE_SKIP_SUCCESS is, and how often ->flush_cqes flag prevents from completion being flushed. Sometimes it's high level of concurrency that enables it at least for one CQE, but sometimes it doesn't save much because nobody waiting on the CQ. Remove ->flush_cqes flag and the optimisation, it should benefit the normal use case. Note, that there is no spurious eventfd problem with that as checks for spuriousness were incorporated into io_eventfd_signal(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/692e81eeddccc096f449a7960365fa7b4a18f8e6.1655637157.git.asml.silence@gmail.com [axboe: remove now dead state->flush_cqes variable] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: move io_eventfd_signal()Pavel Begunkov
Move io_eventfd_signal() in the sources without any changes and kill its forward declaration. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9ebebb3f6f56f5a5448a621e0b6a537720c43334.1655637157.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: remove extra io_commit_cqring()Pavel Begunkov
We don't post events in __io_commit_cqring_flush() anymore but send all requests to tw, so no need to do io_commit_cqring() there. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/f2481e32375e749be89c42e4804268b608722cef.1655637157.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: clean up tracing eventsPavel Begunkov
We have lots of trace events accepting an io_uring request and wanting to print some of its fields like user_data, opcode, flags and so on. However, as trace points were unaware of io_uring structures, we had to pass all the fields as arguments. Teach trace/events/io_uring.h about struct io_kiocb and stop the misery of passing a horde of arguments to trace helpers. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/40ff72f92798114e56d400f2b003beb6cde6ef53.1655384063.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: kill extra io_uring_types.h includesPavel Begunkov
io_uring/io_uring.h already includes io_uring_types.h, no need to include it every time. Kill it in a bunch of places, it prepares us for following patches. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/94d8c943fbe0ef949981c508ddcee7fc1c18850f.1655384063.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: change ->cqe_cached invariant for CQE32Pavel Begunkov
With IORING_SETUP_CQE32 ->cqe_cached doesn't store a real address but rather an implicit offset into cqes. Store the real cqe pointer and increment it accordingly if CQE32. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1ee1838cba16bed96381a006950b36ba640d998c.1655455613.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: introduce io_req_cqe_overflow()Pavel Begunkov
__io_fill_cqe_req() is hot and inlined, we want it to be as small as possible. Add io_req_cqe_overflow() accepting only a request and doing all overflow accounting, and replace with it two calls to 6 argument io_cqring_event_overflow(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/048b9fbcce56814d77a1a540409c98c3d383edcb.1655455613.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>