#
428f1382 |
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14-Feb-2024 |
Jens Axboe <axboe@kernel.dk> |
io_uring/napi: ensure napi polling is aborted when work is available While testing io_uring NAPI with DEFER_TASKRUN, I ran into slowdowns and stalls in packet delivery. Turns out that while io_napi_busy_loop_should_end() aborts appropriately on regular task_work, it does not abort if we have local task_work pending. Move io_has_work() into the private io_uring.h header, and gate whether we should continue polling on that as well. This makes NAPI polling on send/receive work as designed with IORING_SETUP_DEFER_TASKRUN as well. Fixes: 8d0c12a80cde ("io-uring: add napi busy poll support") Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
8d0c12a8 |
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08-Jun-2023 |
Stefan Roesch <shr@devkernel.io> |
io-uring: add napi busy poll support This adds the napi busy polling support in io_uring.c. It adds a new napi_list to the io_ring_ctx structure. This list contains the list of napi_id's that are currently enabled for busy polling. The list is synchronized by the new napi_lock spin lock. The current default napi busy polling time is stored in napi_busy_poll_to. If napi busy polling is not enabled, the value is 0. In addition there is also a hash table. The hash table store the napi id and the pointer to the above list nodes. The hash table is used to speed up the lookup to the list elements. The hash table is synchronized with rcu. The NAPI_TIMEOUT is stored as a timeout to make sure that the time a napi entry is stored in the napi list is limited. The busy poll timeout is also stored as part of the io_wait_queue. This is necessary as for sq polling the poll interval needs to be adjusted and the napi callback allows only to pass in one value. This has been tested with two simple programs from the liburing library repository: the napi client and the napi server program. The client sends a request, which has a timestamp in its payload and the server replies with the same payload. The client calculates the roundtrip time and stores it to calculate the results. The client is running on host1 and the server is running on host 2 (in the same rack). The measured times below are roundtrip times. They are average times over 5 runs each. Each run measures 1 million roundtrips. no rx coal rx coal: frames=88,usecs=33 Default 57us 56us client_poll=100us 47us 46us server_poll=100us 51us 46us client_poll=100us+ 40us 40us server_poll=100us client_poll=100us+ 41us 39us server_poll=100us+ prefer napi busy poll on client client_poll=100us+ 41us 39us server_poll=100us+ prefer napi busy poll on server client_poll=100us+ 41us 39us server_poll=100us+ prefer napi busy poll on client + server Signed-off-by: Stefan Roesch <shr@devkernel.io> Suggested-by: Olivier Langlois <olivier@trillion01.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20230608163839.2891748-5-shr@devkernel.io Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
405b4dc1 |
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08-Jun-2023 |
Stefan Roesch <shr@devkernel.io> |
io-uring: move io_wait_queue definition to header file This moves the definition of the io_wait_queue structure to the header file so it can be also used from other files. Signed-off-by: Stefan Roesch <shr@devkernel.io> Link: https://lore.kernel.org/r/20230608163839.2891748-4-shr@devkernel.io Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
af5d68f8 |
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02-Feb-2024 |
Jens Axboe <axboe@kernel.dk> |
io_uring/sqpoll: manage task_work privately Decouple from task_work running, and cap the number of entries we process at the time. If we exceed that number, push remaining entries to a retry list that we'll process first next time. We cap the number of entries to process at 8, which is fairly random. We just want to get enough per-ctx batching here, while not processing endlessly. Since we manually run PF_IO_WORKER related task_work anyway as the task never exits to userspace, with this we no longer need to add an actual task_work item to the per-process list. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
bfe30bfd |
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28-Jan-2024 |
Jens Axboe <axboe@kernel.dk> |
io_uring: mark the need to lock/unlock the ring as unlikely Any of the fast paths will already have this locked, this helper only exists to deal with io-wq invoking request issue where we do not have the ctx->uring_lock held already. This means that any common or fast path will already have this locked, mark it as such. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
95041b93 |
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28-Jan-2024 |
Jens Axboe <axboe@kernel.dk> |
io_uring: add io_file_can_poll() helper This adds a flag to avoid dipping dereferencing file and then f_op to figure out if the file has a poll handler defined or not. We generally call this at least twice for networked workloads, and if using ring provided buffers, we do it on every buffer selection. Particularly the latter is troublesome, as it's otherwise a very fast operation. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
704ea888 |
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29-Jan-2024 |
Jens Axboe <axboe@kernel.dk> |
io_uring/poll: add requeue return code from poll multishot handling Since our poll handling is edge triggered, multishot handlers retry internally until they know that no more data is available. In preparation for limiting these retries, add an internal return code, IOU_REQUEUE, which can be used to inform the poll backend about the handler wanting to retry, but that this should happen through a normal task_work requeue rather than keep hammering on the issue side for this one request. No functional changes in this patch, nobody is using this return code just yet. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
a4104821 |
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19-Dec-2023 |
Jens Axboe <axboe@kernel.dk> |
io_uring/unix: drop usage of io_uring socket Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to using io_is_uring_fops() to detect whether this is a io_uring fd or not. With that done, kill off io_uring_get_socket() as nobody calls it anymore. This is in preparation to yanking out the rest of the core related to unix gc with io_uring. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
c4320315 |
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19-Dec-2023 |
Jens Axboe <axboe@kernel.dk> |
io_uring/register: move io_uring_register(2) related code to register.c Most of this code is basically self contained, move it out of the core io_uring file to bring a bit more separation to the registration related bits. This moves another ~10% of the code into register.c. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
6b04a373 |
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30-Nov-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring/cmd: inline io_uring_cmd_do_in_task_lazy Now as we can easily include io_uring_types.h, move IOU_F_TWQ_LAZY_WAKE and inline io_uring_cmd_do_in_task_lazy(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/2ec9fb31dd192d1c5cf26d0a2dec5657d88a8e48.1701391955.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
edecf168 |
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27-Nov-2023 |
Jens Axboe <axboe@kernel.dk> |
io_uring: enable io_mem_alloc/free to be used in other parts In preparation for using these helpers, make them non-static and add them to our internal header. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
b3a4dbc8 |
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04-Oct-2023 |
Gabriel Krisman Bertazi <krisman@suse.de> |
io_uring/kbuf: Use slab for struct io_buffer objects The allocation of struct io_buffer for metadata of provided buffers is done through a custom allocator that directly gets pages and fragments them. But, slab would do just fine, as this is not a hot path (in fact, it is a deprecated feature) and, by keeping a custom allocator implementation we lose benefits like tracking, poisoning, sanitizers. Finally, the custom code is more complex and requires keeping the list of pages in struct ctx for no good reason. This patch cleans this path up and just uses slab. I microbenchmarked it by forcing the allocation of a large number of objects with the least number of io_uring commands possible (keeping nbufs=USHRT_MAX), with and without the patch. There is a slight increase in time spent in the allocation with slab, of course, but even when allocating to system resources exhaustion, which is not very realistic and happened around 1/2 billion provided buffers for me, it wasn't a significant hit in system time. Specially if we think of a real-world scenario, an application doing register/unregister of provided buffers will hit ctx->io_buffers_cache more often than actually going to slab. Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://lore.kernel.org/r/20231005000531.30800-4-krisman@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
1658633c |
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02-Oct-2023 |
Jens Axboe <axboe@kernel.dk> |
io_uring: ensure io_lockdep_assert_cq_locked() handles disabled rings io_lockdep_assert_cq_locked() checks that locking is correctly done when a CQE is posted. If the ring is setup in a disabled state with IORING_SETUP_R_DISABLED, then ctx->submitter_task isn't assigned until the ring is later enabled. We generally don't post CQEs in this state, as no SQEs can be submitted. However it is possible to generate a CQE if tagged resources are being updated. If this happens and PROVE_LOCKING is enabled, then the locking check helper will dereference ctx->submitter_task, which hasn't been set yet. Fixup io_lockdep_assert_cq_locked() to handle this case correctly. While at it, convert it to a static inline as well, so that generated line offsets will actually reflect which condition failed, rather than just the line offset for io_lockdep_assert_cq_locked() itself. Reported-and-tested-by: syzbot+efc45d4e7ba6ab4ef1eb@syzkaller.appspotmail.com Fixes: f26cc9593581 ("io_uring: lockdep annotate CQ locking") Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
093a650b |
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24-Aug-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: force inline io_fill_cqe_req There are only 2 callers of io_fill_cqe_req left, and one of them is extremely hot. Force inline the function. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/ffce4fc5e3521966def848a4d930586dfe33ae11.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
ec26c225 |
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24-Aug-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: merge iopoll and normal completion paths io_do_iopoll() and io_submit_flush_completions() are pretty similar, both filling CQEs and then free a list of requests. Don't duplicate it and make iopoll use __io_submit_flush_completions(), which also helps with inlining and other optimisations. For that, we need to first find all completed iopoll requests and splice them from the iopoll list and then pass it down. This adds one extra list traversal, which should be fine as requests will stay hot in cache. CQ locking is already conditional, introduce ->lockless_cq and skip locking for IOPOLL as it's protected by ->uring_lock. We also add a wakeup optimisation for IOPOLL to __io_cq_unlock_post(), so it works just like io_cqring_ev_posted_iopoll(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3840473f5e8a960de35b77292026691880f6bdbc.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
59fbc409 |
|
24-Aug-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: optimise extra io_get_cqe null check If the cached cqe check passes in io_get_cqe*() it already means that the cqe we return is valid and non-zero, however the compiler is unable to optimise null checks like in io_fill_cqe_req(). Do a bit of trickery, return success/fail boolean from io_get_cqe*() and store cqe in the cqe parameter. That makes it do the right thing, erasing the check together with the introduced indirection. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/322ea4d3377d3d4efd8ae90ab8ed28a99f518210.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
20d6b633 |
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24-Aug-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: refactor __io_get_cqe() Make __io_get_cqe simpler by not grabbing the cqe from refilled cached, but letting io_get_cqe() do it for us. That's cleaner and removes some duplication. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/74dc8fdf2657e438b2e05e1d478a3596924604e9.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
b24c5d75 |
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24-Aug-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: simplify big_cqe handling Don't keep big_cqe bits of req in a union with hash_node, find a separate space for it. It's bit safer, but also if we keep it always initialised, we can get rid of ugly REQ_F_CQE32_INIT handling. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/447aa1b2968978c99e655ba88db536e903df0fe9.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
a0727c73 |
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24-Aug-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: improve cqe !tracing hot path While looking at io_fill_cqe_req()'s asm I stumbled on our trace points turning into the chunk below: trace_io_uring_complete(req->ctx, req, req->cqe.user_data, req->cqe.res, req->cqe.flags, req->extra1, req->extra2); io_uring/io_uring.c:898: trace_io_uring_complete(req->ctx, req, req->cqe.user_data, movq 232(%rbx), %rdi # req_44(D)->big_cqe.extra2, _5 movq 224(%rbx), %rdx # req_44(D)->big_cqe.extra1, _6 movl 84(%rbx), %r9d # req_44(D)->cqe.D.81184.flags, _7 movl 80(%rbx), %r8d # req_44(D)->cqe.res, _8 movq 72(%rbx), %rcx # req_44(D)->cqe.user_data, _9 movq 88(%rbx), %rsi # req_44(D)->ctx, _10 ./arch/x86/include/asm/jump_label.h:27: asm_volatile_goto("1:" 1:jmp .L1772 # objtool NOPs this # ... It does a jump_label for actual tracing, but those 6 moves will stay there in the hottest io_uring path. As an optimisation, add a trace_io_uring_complete_enabled() check, which is also uses jump_labels, it tricks the compiler into behaving. It removes the junk without changing anything else int the hot path. Note: apparently, it's not only me noticing it, and people are also working it around. We should remove the check when it's solved generically or rework tracing. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/555d8312644b3776f4be7e23f9b92943875c4bc7.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
b6b2bb58 |
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11-Aug-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: never overflow io_aux_cqe Now all callers of io_aux_cqe() set allow_overflow to false, remove the parameter and not allow overflowing auxilary multishot cqes. When CQ is full the function callers and all multishot requests in general are expected to complete the request. That prevents indefinite in-background grows of the overflow list and let's the userspace to handle the backlog at its own pace. Resubmitting a request should also be faster than accounting a bunch of overflows, so it should be better for perf when it happens, but a well behaving userspace should be trying to avoid overflows in any case. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/bb20d14d708ea174721e58bb53786b0521e4dd6d.1691757663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
056695bf |
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11-Aug-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: remove return from io_req_cqe_overflow() Nobody checks io_req_cqe_overflow()'s return, make it return void. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/8f2029ad0c22f73451664172d834372608ee0a77.1691757663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
00b0db56 |
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11-Aug-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: open code io_fill_cqe_req() io_fill_cqe_req() is only called from one place, open code it, and rename __io_fill_cqe_req(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/f432ce75bb1c94cadf0bd2add4d6aa510bd1fb36.1691757663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
17bc2837 |
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07-Jul-2023 |
Jens Axboe <axboe@kernel.dk> |
io_uring: have io_file_put() take an io_kiocb rather than the file No functional changes in this patch, just a prep patch for needing the request in io_file_put(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
569f5308 |
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09-Aug-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: fix false positive KASAN warnings io_req_local_work_add() peeks into the work list, which can be executed in the meanwhile. It's completely fine without KASAN as we're in an RCU read section and it's SLAB_TYPESAFE_BY_RCU. With KASAN though it may trigger a false positive warning because internal io_uring caches are sanitised. Remove sanitisation from the io_uring request cache for now. Cc: stable@vger.kernel.org Fixes: 8751d15426a31 ("io_uring: reduce scheduling due to tw") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/c6fbf7a82a341e66a0007c76eefd9d57f2d3ba51.1691541473.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
0fdb9a19 |
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22-Jun-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: make io_cq_unlock_post static io_cq_unlock_post() is exclusively used in io_uring/io_uring.c, mark it static and don't expose to other files. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3dc8127dda4514e1dd24bb32035faac887c5fa37.1687518903.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
91c7884a |
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22-Jun-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: remove IOU_F_TWQ_FORCE_NORMAL Extract a function for non-local task_work_add, and use it directly from io_move_task_work_from_local(). Now we don't use IOU_F_TWQ_FORCE_NORMAL and it can be killed. As a small positive side effect we don't grab task->io_uring in io_req_normal_work_add anymore, which is not needed for io_req_local_work_add(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/2e55571e8ff2927ae3cc12da606d204e2485525b.1687518903.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
3beed235 |
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20-Jun-2023 |
Christoph Hellwig <hch@lst.de> |
io_uring: remove io_req_ffs_set Just checking the flag directly makes it a lot more obvious what is going on here. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230620113235.920399-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
d86eaed1 |
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07-Jun-2023 |
Jens Axboe <axboe@kernel.dk> |
io_uring: cleanup io_aux_cqe() API Everybody is passing in the request, so get rid of the io_ring_ctx and explicit user_data pass-in. Both the ctx and user_data can be deduced from the request at hand. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
6e76ac59 |
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28-Apr-2023 |
Josh Triplett <josh@joshtriplett.org> |
io_uring: Add io_uring_setup flag to pre-register ring fd and never install it With IORING_REGISTER_USE_REGISTERED_RING, an application can register the ring fd and use it via registered index rather than installed fd. This allows using a registered ring for everything *except* the initial mmap. With IORING_SETUP_NO_MMAP, io_uring_setup uses buffers allocated by the user, rather than requiring a subsequent mmap. The combination of the two allows a user to operate *entirely* via a registered ring fd, making it unnecessary to ever install the fd in the first place. So, add a flag IORING_SETUP_REGISTERED_FD_ONLY to make io_uring_setup register the fd and return a registered index, without installing the fd. This allows an application to avoid touching the fd table at all, and allows a library to never even momentarily install a file descriptor. This splits out an io_ring_add_registered_file helper from io_ring_add_registered_fd, for use by io_uring_setup. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Link: https://lore.kernel.org/r/bc8f431bada371c183b95a83399628b605e978a3.1682699803.git.josh@joshtriplett.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
96c7d4f8 |
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04-May-2023 |
Breno Leitao <leitao@debian.org> |
io_uring: Create a helper to return the SQE size Create a simple helper that returns the size of the SQE. The SQE could have two size, depending of the flags. If IO_URING_SETUP_SQE128 flag is set, then return a double SQE, otherwise returns the sizeof of io_uring_sqe (64 bytes). Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/20230504121856.904491-2-leitao@debian.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
8ce4269e |
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10-Apr-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: add irq lockdep checks We don't post CQEs from the IRQ context, add a check catching that. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/f23f7a24dbe8027b3d37873fece2b6488f878b31.1681210788.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
8751d154 |
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06-Apr-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: reduce scheduling due to tw Every task_work will try to wake the task to be executed, which causes excessive scheduling and additional overhead. For some tw it's justified, but others won't do much but post a single CQE. When a task waits for multiple cqes, every such task_work will wake it up. Instead, the task may give a hint about how many cqes it waits for, io_req_local_work_add() will compare against it and skip wake ups if #cqes + #tw is not enough to satisfy the waiting condition. Task_work that uses the optimisation should be simple enough and never post more than one CQE. It's also ignored for non DEFER_TASKRUN rings. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/d2b77e99d1e86624d8a69f7037d764b739dcd225.1680782017.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
8501fe70 |
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06-Apr-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: add tw add flags We pass 'allow_local' into io_req_task_work_add() but will need more flags. Replace it with a flags bit field and name this allow_local flag. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/4c0f01e7ef4e6feebfb199093cc995af7a19befa.1680782017.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
6e7248ad |
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06-Apr-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: refactor io_cqring_wake() Instead of smp_mb() + __io_cqring_wake() in __io_cq_unlock_post_flush() use equivalent io_cqring_wake(). With that we can clean it up further and remove __io_cqring_wake(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/662ee5d898168ac206be06038525e97b64072a46.1680782017.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
e3ef728f |
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30-Mar-2023 |
Jens Axboe <axboe@kernel.dk> |
io_uring: cap io_sqring_entries() at SQ ring size We already do this manually for the !SQPOLL case, do it in general and we can also dump the ugly min3() in io_submit_sqes(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
a282967c |
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27-Mar-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: encapsulate task_work state For task works we're passing around a bool pointer for whether the current ring is locked or not, let's wrap it in a structure, that will make it more opaque preventing abuse and will also help us to pass more info in the future if needed. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1ecec9483d58696e248d1bfd52cf62b04442df1d.1679931367.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
2f2bb1ff |
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06-Feb-2023 |
Jens Axboe <axboe@kernel.dk> |
io_uring: mark task TASK_RUNNING before handling resume/task work Just like for task_work, set the task mode to TASK_RUNNING before doing any potential resume work. We're not holding any locks at this point, but we may have already set the task state to TASK_INTERRUPTIBLE in preparation for going to sleep waiting for events. Ensure that we set it back to TASK_RUNNING if we have work to process, to avoid warnings on calling blocking operations with !TASK_RUNNING. Fixes: b5d3ae202fbf ("io_uring: handle TIF_NOTIFY_RESUME when checking for task_work") Reported-by: kernel test robot <oliver.sang@intel.com> Link: https://lore.kernel.org/oe-lkp/202302062208.24d3e563-oliver.sang@intel.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
c8576f3e |
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23-Jan-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: refactor req allocation Follow the io_get_sqe pattern returning the result via a pointer and hide request cache refill inside io_alloc_req(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/8c37c2e8a3cb5e4cd6a8ae3b91371227a92708a6.1674484266.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
c1755c25 |
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18-Jan-2023 |
Breno Leitao <leitao@debian.org> |
io_uring: Enable KASAN for request cache Every io_uring request is represented by struct io_kiocb, which is cached locally by io_uring (not SLAB/SLUB) in the list called submit_state.freelist. This patch simply enabled KASAN for this free list. This list is initially created by KMEM_CACHE, but later, managed by io_uring. This patch basically poisons the objects that are not used (i.e., they are the free list), and unpoisons it when the object is allocated/removed from the list. Touching these poisoned objects while in the freelist will cause a KASAN warning. Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
b5d3ae20 |
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24-Jan-2023 |
Jens Axboe <axboe@kernel.dk> |
io_uring: handle TIF_NOTIFY_RESUME when checking for task_work If TIF_NOTIFY_RESUME is set, then we need to call resume_user_mode_work() for PF_IO_WORKER threads. They never return to usermode, hence never get a chance to process any items that are marked by this flag. Most notably this includes the final put of files, but also any throttling markers set by block cgroups. Cc: stable@vger.kernel.org # 5.10+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
89800a2d |
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16-Jan-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: don't export io_put_task() io_put_task() is only used in uring.c so enclose it there together with __io_put_task(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/43c7f9227e2ab215f1a6069dadbc5382bed346fe.1673887636.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
bca39f39 |
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09-Jan-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: add lazy poll_wq activation Even though io_poll_wq_wake()'s waitqueue_active reuses a barrier we do for another waitqueue, it's not going to be the case in the future and so we want to have a fast path for it when the ring has never been polled. Move poll_wq wake ups into __io_commit_cqring_flush() using a new flag called ->poll_activated. The idea behind the flag is to set it when the ring was polled for the first time. This requires additional sync to not miss events, which is done here by using task_work for ->task_complete rings, and by default enabling the flag for all other types of rings. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/060785e8e9137a920b232c0c7f575b131af19cac.1673274244.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
7b235dd8 |
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09-Jan-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: separate wq for ring polling Don't use ->cq_wait for ring polling but add a separate wait queue for it. We need it for following patches. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/dea0be0bf990503443c5c6c337fc66824af7d590.1673274244.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
360173ab |
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09-Jan-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: move io_run_local_work_locked io_run_local_work_locked() is only used in io_uring.c, move it there. With that we can also make __io_run_local_work() static. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/91757bcb33e5774e49fed6f2b6e058630608119b.1673274244.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
3e565555 |
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09-Jan-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: mark io_run_local_work static io_run_local_work is enclosed in io_uring.c, we don't need to export it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/b477fb81f5e77044f724a06fe245d5c078659364.1673274244.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
140102ae |
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05-Jan-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: move defer tw task checks Most places that want to run local tw explicitly and in advance check if they are allowed to do so. Don't rely on a similar check in __io_run_local_work(), leave it as a just-in-case warning and make sure callers checks capabilities themselves. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/990fe0e8e70fd4d57e43625e5ce8fba584821d1a.1672916894.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
1414d629 |
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05-Jan-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: kill io_run_task_work_ctx There is only one user of io_run_task_work_ctx(), inline it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/40953c65f7c88fb00cdc4d870ca5d5319fb3d7ea.1672916894.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
0c4fe008 |
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05-Jan-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: rearrange defer list checks There should be nothing in the ->work_llist for non DEFER_TASKRUN rings, so we can skip flag checks and test the list emptiness directly. Also move it out of io_run_local_work() for inlining. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/331d63fd15ca79b35b95c82a82d9246110686392.1672916894.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
f26cc959 |
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03-Jan-2023 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: lockdep annotate CQ locking Locking around CQE posting is complex and depends on options the ring is created with, add more thorough lockdep annotations checking all invariants. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/aa3770b4eacae3915d782cc2ab2f395a99b4b232.1672795976.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
6434ec01 |
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17-Dec-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: don't use TIF_NOTIFY_SIGNAL to test for availability of task_work Use task_work_pending() as a better test for whether we have task_work or not, TIF_NOTIFY_SIGNAL is only valid if the any of the task_work items had been queued with TWA_SIGNAL as the notification mechanism. Hence task_work_pending() is a more reliable check. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
6971253f |
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02-Dec-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: revise completion_lock locking io_kill_timeouts() doesn't post any events but queues everything to task_work. Locking there is needed for protecting linked requests traversing, we should grab completion_lock directly instead of using io_cq_[un]lock helpers. Same goes for __io_req_find_next_prep(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/88e75d481a65dc295cb59722bb1cf76402d1c06b.1670002973.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
f66f7342 |
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07-Dec-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: skip spinlocking for ->task_complete ->task_complete was added to serialised CQE posting by doing it from the task context only (or fallback wq when the task is dead), and now we can use that to avoid taking ->completion_lock while filling CQ entries. The patch skips spinlocking only in two spots, __io_submit_flush_completions() and flushing in io_aux_cqe, it's safer and covers all cases we care about. Extra care is taken to force taking the lock while queueing overflow entries. It fundamentally relies on SINGLE_ISSUER to have only one task posting events. It also need to take into account overflowed CQEs, flushing of which happens in the cq wait path, and so this implementation also needs DEFER_TASKRUN to limit waiters. For the same reason we disable it for SQPOLL, and for IOPOLL as it won't benefit from it in any case. DEFER_TASKRUN, SQPOLL and IOPOLL requirement may be relaxed in the future. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/2a8c91fd82cfcdcc1d2e5bac7051fe2c183bda73.1670384893.git.asml.silence@gmail.com [axboe: modify to apply] Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
618d653a |
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30-Nov-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: don't raw spin unlock to match cq_lock There is one newly added place when we lock ring with io_cq_lock() but unlocking is hand coded calling spin_unlock directly. It's ugly and troublesome in the long run. Make it consistent with the other completion locking. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/4ca4f0564492b90214a190cd5b2a6c76522de138.1669821213.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
27f35fe9 |
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25-Nov-2022 |
Dylan Yudaken <dylany@meta.com> |
io_uring: remove io_req_complete_post_tw It's only used in one place. Inline it. Signed-off-by: Dylan Yudaken <dylany@meta.com> Link: https://lore.kernel.org/r/20221125103412.1425305-2-dylany@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
b529c96a |
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24-Nov-2022 |
Dylan Yudaken <dylany@meta.com> |
io_uring: remove overflow param from io_post_aux_cqe The only call sites which would not allow overflow are also call sites which would use the io_aux_cqe as they care about ordering. So remove this parameter from io_post_aux_cqe. Signed-off-by: Dylan Yudaken <dylany@meta.com> Link: https://lore.kernel.org/r/20221124093559.3780686-9-dylany@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
a77ab745 |
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24-Nov-2022 |
Dylan Yudaken <dylany@meta.com> |
io_uring: make io_fill_cqe_aux static This is only used in io_uring.c Signed-off-by: Dylan Yudaken <dylany@meta.com> Link: https://lore.kernel.org/r/20221124093559.3780686-7-dylany@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
9b8c5475 |
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24-Nov-2022 |
Dylan Yudaken <dylany@meta.com> |
io_uring: add io_aux_cqe which allows deferred completion Use the just introduced deferred post cqe completion state when possible in io_aux_cqe. If not possible fallback to io_post_aux_cqe. This introduces a complication because of allow_overflow. For deferred completions we cannot know without locking the completion_lock if it will overflow (and even if we locked it, another post could sneak in and cause this cqe to be in overflow). However since overflow protection is mostly a best effort defence in depth to prevent infinite loops of CQEs for poll, just checking the overflow bit is going to be good enough and will result in at most 16 (array size of deferred cqes) overflows. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Dylan Yudaken <dylany@meta.com> Link: https://lore.kernel.org/r/20221124093559.3780686-6-dylany@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
973fc83f |
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24-Nov-2022 |
Dylan Yudaken <dylany@meta.com> |
io_uring: defer all io_req_complete_failed All failures happen under lock now, and can be deferred. To be consistent when the failure has happened after some multishot cqe has been deferred (and keep ordering), always defer failures. To make this obvious at the caller (and to help prevent a future bug) rename io_req_complete_failed to io_req_defer_failed. Signed-off-by: Dylan Yudaken <dylany@meta.com> Link: https://lore.kernel.org/r/20221124093559.3780686-4-dylany@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
1bec951c |
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23-Nov-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: iopoll protect complete_post io_req_complete_post() may be used by iopoll enabled rings, grab locks in this case. That requires to pass issue_flags to propagate the locking state. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/cc6d854065c57c838ca8e8806f707a226b70fd2d.1669203009.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
833b5dff |
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23-Nov-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: remove io_req_tw_post_queue Remove io_req_tw_post() and io_req_tw_post_queue(), we can use io_req_task_complete() instead. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/b9b73c08022c7f1457023ac841f35c0100e70345.1669203009.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
44648532 |
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20-Nov-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups Pass in EPOLL_URING_WAKE when signaling eventfd or doing poll related wakups, so that we can check for a circular event dependency between eventfd and epoll. If this flag is set when our wakeup handlers are called, then we know we have a dependency that needs to terminate multishot requests. eventfd and epoll are the only such possible dependencies. Cc: stable@vger.kernel.org # 6.0 Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
f9d567c7 |
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17-Nov-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: inline __io_req_complete_post() There is only one user of __io_req_complete_post(), inline it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/ef4c9059950a3da5cf68df00f977f1fd13bd9306.1668597569.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
e52d2e58 |
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11-Nov-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: inline io_req_task_work_add() __io_req_task_work_add() is huge but marked inline, that makes compilers to generate lots of garbage. Inline the wrapper caller io_req_task_work_add() instead. before and after: text data bss dec hex filename 47347 16248 8 63603 f873 io_uring/io_uring.o text data bss dec hex filename 45303 16248 8 61559 f077 io_uring/io_uring.o Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/26dc8c28ca0160e3269ef3e55c5a8b917c4d4450.1668162751.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
7cfe7a09 |
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25-Nov-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: clear TIF_NOTIFY_SIGNAL if set and task_work not available With how task_work is added and signaled, we can have TIF_NOTIFY_SIGNAL set and no task_work pending as it got run in a previous loop. Treat TIF_NOTIFY_SIGNAL like get_signal(), always clear it if set regardless of whether or not task_work is pending to run. Cc: stable@vger.kernel.org Fixes: 46a525e199e4 ("io_uring: don't gate task_work run on TIF_NOTIFY_SIGNAL") Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
91482864 |
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17-Nov-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: fix multishot accept request leaks Having REQ_F_POLLED set doesn't guarantee that the request is executed as a multishot from the polling path. Fortunately for us, if the code thinks it's multishot issue when it's not, it can only ask to skip completion so leaking the request. Use issue_flags to mark multipoll issues. Cc: stable@vger.kernel.org Fixes: 390ed29b5e425 ("io_uring: add IORING_ACCEPT_MULTISHOT for accept") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/7700ac57653f2823e30b34dc74da68678c0c5f13.1668710222.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
b3026767 |
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27-Oct-2022 |
Dylan Yudaken <dylany@meta.com> |
io_uring: unlock if __io_run_local_work locked inside It is possible for tw to lock the ring, and this was not propogated out to io_run_local_work. This can cause an unlock to be missed. Instead pass a pointer to locked into __io_run_local_work. Fixes: 8ac5d85a89b4 ("io_uring: add local task_work run helper that is entered locked") Signed-off-by: Dylan Yudaken <dylany@meta.com> Link: https://lore.kernel.org/r/20221027144429.3971400-3-dylany@meta.com [axboe: WARN_ON() -> WARN_ON_ONCE() and add a minor comment] Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
44f87745 |
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06-Oct-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: optimise locking for local tw with submit_wait Running local task_work requires taking uring_lock, for submit + wait we can try to run them right after submit while we still hold the lock and save one lock/unlokc pair. The optimisation was implemented in the first local tw patches but got dropped for simplicity. Suggested-by: Dylan Yudaken <dylany@fb.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/281fc79d98b5d91fe4778c5137a17a2ab4693e5c.1665088876.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
fc86f9d3 |
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05-Oct-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: remove redundant memory barrier in io_req_local_work_add io_cqring_wake() needs a barrier for the waitqueue_active() check. However, in the case of io_req_local_work_add(), we call llist_add() first, which implies an atomic. Hence we can replace smb_mb() with smp_mb__after_atomic(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/43983bc8bc507172adda7a0f00cab1aff09fd238.1665018309.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
46a525e1 |
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29-Sep-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: don't gate task_work run on TIF_NOTIFY_SIGNAL This isn't a reliable mechanism to tell if we have task_work pending, we really should be looking at whether we have any items queued. This is problematic if forward progress is gated on running said task_work. One such example is reading from a pipe, where the write side has been closed right before the read is started. The fput() of the file queues TWA_RESUME task_work, and we need that task_work to be run before ->release() is called for the pipe. If ->release() isn't called, then the read will sit forever waiting on data that will never arise. Fix this by io_run_task_work() so it checks if we have task_work pending rather than rely on TIF_NOTIFY_SIGNAL for that. The latter obviously doesn't work for task_work that is queued without TWA_SIGNAL. Reported-by: Christiano Haesbaert <haesbaert@haesbaert.org> Cc: stable@vger.kernel.org Link: https://github.com/axboe/liburing/issues/665 Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
aa1df3a3 |
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23-Sep-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: fix CQE reordering Overflowing CQEs may result in reordering, which is buggy in case of links, F_MORE and so on. If we guarantee that we don't reorder for the unlikely event of a CQ ring overflow, then we can further extend this to not have to terminate multishot requests if it happens. For other operations, like zerocopy sends, we have no choice but to honor CQE ordering. Reported-by: Dylan Yudaken <dylany@fb.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/ec3bc55687b0768bbe20fb62d7d06cfced7d7e70.1663892031.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
6567506b |
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08-Sep-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: disallow defer-tw run w/ no submitters We try to restrict CQ waiters when IORING_SETUP_DEFER_TASKRUN is set, but if nothing has been submitted yet it'll allow any waiter, which violates the contract. Fixes: c0e0d6ba25f1 ("io_uring: add IORING_SETUP_DEFER_TASKRUN") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/b4f0d3f14236d7059d08c5abe2661ef0b78b5528.1662652536.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
76de6749 |
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08-Sep-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: further limit non-owner defer-tw cq waiting In case of DEFER_TASK_WORK we try to restrict waiters to only one task, which is also the only submitter; however, we don't do it reliably, which might be very confusing and backfire in the future. E.g. we currently allow multiple tasks in io_iopoll_check(). Fixes: c0e0d6ba25f1 ("io_uring: add IORING_SETUP_DEFER_TASKRUN") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/94c83c0a7fe468260ee2ec31bdb0095d6e874ba2.1662652536.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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dac6a0ea |
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03-Sep-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: ensure iopoll runs local task work as well Combine the two checks we have for task_work running and whether or not we need to shuffle the mutex into one, so we unify how task_work is run in the iopoll loop. This helps ensure that local task_work is run when needed, and also optimizes that path to avoid a mutex shuffle if it's not needed. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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8ac5d85a |
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03-Sep-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: add local task_work run helper that is entered locked We have a few spots that drop the mutex just to run local task_work, which immediately tries to grab it again. Add a helper that just passes in whether we're locked already. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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c0e0d6ba |
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30-Aug-2022 |
Dylan Yudaken <dylany@fb.com> |
io_uring: add IORING_SETUP_DEFER_TASKRUN 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>
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bd1a3783 |
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27-Jul-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: export req alloc from core 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>
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63809137 |
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12-Jul-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: flush notifiers after sendzc 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>
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eb42cebb |
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12-Jul-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: add zc notification infrastructure 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>
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e70cb608 |
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12-Jul-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: export io_put_task() 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>
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f6b543fd |
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21-Jul-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: ensure REQ_F_ISREG is set async offload 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>
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e0486f3f |
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30-Jun-2022 |
Dylan Yudaken <dylany@fb.com> |
io_uring: only trace one of complete or overflow 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>
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52120f0f |
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30-Jun-2022 |
Dylan Yudaken <dylany@fb.com> |
io_uring: add allow_overflow to io_post_aux_cqe 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>
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114eccdf |
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30-Jun-2022 |
Dylan Yudaken <dylany@fb.com> |
io_uring: add IOU_STOP_MULTISHOT return code For multishot we want a way to signal the caller that multishot has ended but also this might not be an error return. For example sockets return 0 when closed, which should end a multishot recv, but still have a CQE with result 0 Introduce IOU_STOP_MULTISHOT which does this and indicates that the return code is stored inside req->cqe Signed-off-by: Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220630091231.1456789-7-dylany@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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ed5ccb3b |
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22-Jun-2022 |
Dylan Yudaken <dylany@fb.com> |
io_uring: remove priority tw list optimisation 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>
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a6b21fbb |
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21-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: move list helpers to a separate file It's annoying to have io-wq.h as a dependency every time we want some of struct io_wq_work_list helpers, move them into a separate file. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/c1d891ce12b30767d1d2a3b7db2ca3abc1ecc4a2.1655802465.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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625d38b3 |
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21-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: improve io_run_task_work() Since SQPOLL now uses TWA_SIGNAL_NO_IPI, there won't be task work items without TIF_NOTIFY_SIGNAL. Simplify io_run_task_work() by removing task->task_works check. Even though looks it doesn't cause extra cache bouncing, it's still nice to not touch it an extra time when it might be not cached. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/75d4f34b0c671075892821a409e28da6cb1d64fe.1655802465.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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9da070b1 |
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19-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: consistent naming for inline completion 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>
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46929b08 |
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19-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: add io_commit_cqring_flush() 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>
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25399321 |
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19-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: introduce locking helpers for CQE posting 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>
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d9dee430 |
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18-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: remove ->flush_cqes optimisation 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>
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9046c641 |
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18-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: reshuffle io_uring/io_uring.h It's a good idea to first do forward declarations and then inline helpers, otherwise there will be keep stumbling on dependencies between them. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1d7fa6672ed43f20ccc0c54ae201369ebc3ebfab.1655637157.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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ab1c84d8 |
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16-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: make io_uring_types.h public Move io_uring types to linux/include, need them public so tracing can see the definitions and we can clean trace/events/io_uring.h Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/a15f12e8cb7289b2de0deaddcc7518d98a132d17.1655384063.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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b3659a65 |
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17-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: change ->cqe_cached invariant for CQE32 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>
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e8c328c3 |
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17-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: deduplicate io_get_cqe() calls Deduplicate calls to io_get_cqe() from __io_fill_cqe_req(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/4fa077986cc3abab7c59ff4e7c390c783885465f.1655455613.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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ae5735c6 |
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17-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: deduplicate __io_fill_cqe_req tracing Deduplicate two trace_io_uring_complete() calls in __io_fill_cqe_req(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/277ed85dba5189ab7d932164b314013a0f0b0fdc.1655455613.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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68494a65 |
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17-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: introduce io_req_cqe_overflow() __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>
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faf88dde |
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17-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: don't inline __io_get_cqe() __io_get_cqe() is not as hot as io_get_cqe(), no need to inline it, it sheds ~500B from the binary. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/c1ac829198a881b7af8710926f99a3559b9f24c0.1655455613.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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d245bca6 |
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17-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: don't expose io_fill_cqe_aux() Deduplicate some code and add a helper for filling an aux CQE, locking and notification. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/b7c6557c8f9dc5c4cfb01292116c682a0ff61081.1655455613.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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75d7b3ae |
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16-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: kill REQ_F_COMPLETE_INLINE REQ_F_COMPLETE_INLINE is only needed to delay queueing into the completion list to io_queue_sqe() as __io_req_complete() is inlined and we don't want to bloat the kernel. As now we complete in a more centralised fashion in io_issue_sqe() we can get rid of the flag and queue to the list directly. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/600ba20a9338b8a39b249b23d3d177803613dde4.1655371007.git.asml.silence@gmail.com Reviewed-by: Hao Xu <howeyxu@tencent.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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aa1e90f6 |
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15-Jun-2022 |
Pavel Begunkov <asml.silence@gmail.com> |
io_uring: move small helpers to headers There is a bunch of inline helpers that will be useful not only to the core of io_uring, move them to headers. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/22df99c83723e44cba7e945e8519e64e3642c064.1655310733.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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f3b44f92 |
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13-Jun-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: move read/write related opcodes to its own file Signed-off-by: Jens Axboe <axboe@kernel.dk>
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c98817e6 |
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26-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: move remaining file table manipulation to filetable.c Signed-off-by: Jens Axboe <axboe@kernel.dk>
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73572984 |
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13-Jun-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: move rsrc related data, core, and commands Signed-off-by: Jens Axboe <axboe@kernel.dk>
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3b77495a |
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13-Jun-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: split provided buffers handling into its own file Move both the opcodes related to it, and the internals code dealing with it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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7aaff708 |
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25-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: move cancelation into its own file This also helps cleanup the io_uring.h cancel parts, as we can make things static in the cancel.c file, mostly. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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329061d3 |
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25-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: move poll handling into its own file Add a io_poll_issue() rather than export the general task_work locking and io_issue_sqe(), and put the io_op_defs definition and structure into a separate header file so that poll can use it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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c9f06aa7 |
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25-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: move io_uring_task (tctx) helpers into its own file Signed-off-by: Jens Axboe <axboe@kernel.dk>
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17437f31 |
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25-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: move SQPOLL related handling into its own file Signed-off-by: Jens Axboe <axboe@kernel.dk>
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59915143 |
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25-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: move timeout opcodes and handling into its own file Signed-off-by: Jens Axboe <axboe@kernel.dk>
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f9ead18c |
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25-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: split network related opcodes into its own file While at it, convert the handlers to just use io_eopnotsupp_prep() if CONFIG_NET isn't set. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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99f15d8d |
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25-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: move uring_cmd handling to its own file Signed-off-by: Jens Axboe <axboe@kernel.dk>
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cd40cae2 |
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24-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: split out open/close operations Signed-off-by: Jens Axboe <axboe@kernel.dk>
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531113bb |
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24-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: split out splice related operations This splits out splice and tee support. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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97b388d7 |
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24-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: handle completions in the core Normally request handlers complete requests themselves, if they don't return an error. For the latter case, the core will complete it for them. This is unhandy for pushing opcode handlers further out, as we don't want a bunch of inline completion code and we don't want to make the completion path slower than it is now. Let the core handle any completion, unless the handler explicitly asks us not to. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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de23077e |
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24-May-2022 |
Jens Axboe <axboe@kernel.dk> |
io_uring: set completion results upfront Signed-off-by: Jens Axboe <axboe@kernel.dk>
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