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* io_uring: user registered clockid for wait timeoutsPavel Begunkov2024-08-251-1/+1
| | | | | | | | | | | | Add a new registration opcode IORING_REGISTER_CLOCK, which allows the user to select which clock id it wants to use with CQ waiting timeouts. It only allows a subset of all posix clocks and currently supports CLOCK_MONOTONIC and CLOCK_BOOTTIME. Suggested-by: Lewis Baker <lewissbaker@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/98f2bc8a3c36cdf8f0e6a275245e81e903459703.1723039801.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring/napi: postpone napi timeout adjustmentPavel Begunkov2024-08-251-21/+7
| | | | | | | | | | | | | Remove io_napi_adjust_timeout() and move the adjustments out of the common path into __io_napi_busy_loop(). Now the limit it's calculated based on struct io_wait_queue::timeout, for which we query current time another time. The overhead shouldn't be a problem, it's a polling path, however that can be optimised later by additionally saving the delta time value in io_cqring_wait(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/88e14686e245b3b42ff90a3c4d70895d48676206.1723039801.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring/napi: refactor __io_napi_busy_loop()Pavel Begunkov2024-08-251-3/+4
| | | | | | | | | we don't need to set ->napi_prefer_busy_poll if we're not going to poll, do the checks first and all polling preparation after. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/2ad7ede8cc7905328fc62e8c3805fdb11635ae0b.1723039801.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring/napi: remove duplicate io_napi_entry timeout assignationOlivier Langlois2024-08-121-1/+0
| | | | | | | | | | | | | io_napi_entry() has 2 calling sites. One of them is unlikely to find an entry and if it does, the timeout should arguable not be updated. The other io_napi_entry() calling site is overwriting the update made by io_napi_entry() so the io_napi_entry() timeout value update has no or little value and therefore is removed. Signed-off-by: Olivier Langlois <olivier@trillion01.com> Link: https://lore.kernel.org/r/145b54ff179f87609e20dffaf5563c07cdbcad1a.1723423275.git.olivier@trillion01.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring/napi: check napi_enabled in io_napi_add() before proceedingOlivier Langlois2024-08-121-1/+1
| | | | | | | | | | | | | doing so avoids the overhead of adding napi ids to all the rings that do not enable napi. if no id is added to napi_list because napi is disabled, __io_napi_busy_loop() will not be called. Signed-off-by: Olivier Langlois <olivier@trillion01.com> Fixes: b4ccc4dd1330 ("io_uring/napi: enable even with a timeout of 0") Link: https://lore.kernel.org/r/bd989ccef5fda14f5fd9888faf4fefcf66bd0369.1723400131.git.olivier@trillion01.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring: remove unused local list heads in NAPI functionsOlivier Langlois2024-07-301-2/+0
| | | | | | | | | These lists are unused, remove them. Signed-off-by: Olivier Langlois <olivier@trillion01.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0a0ae3e955aed0f3e3d29882fb3d3cb575e0009b.1722294947.git.olivier@trillion01.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring/napi: pass ktime to io_napi_adjust_timeoutPavel Begunkov2024-07-261-11/+3
| | | | | | | | | | Pass the waiting time for __io_napi_adjust_timeout as ktime and get rid of all timespec64 conversions. It's especially simpler since the caller already have a ktime. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/4f5b8e8eed4f53a1879e031a6712b25381adc23d.1722003776.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring/napi: use ktime in busy pollingPavel Begunkov2024-07-261-21/+27
| | | | | | | | | | | | | | | | | | | | It's more natural to use ktime/ns instead of keeping around usec, especially since we're comparing it against user provided timers, so convert napi busy poll internal handling to ktime. It's also nicer since the type (ktime_t vs unsigned long) now tells the unit of measure. Keep everything as ktime, which we convert to/from micro seconds for IORING_[UN]REGISTER_NAPI. The net/ busy polling works seems to work with usec, however it's not real usec as shift by 10 is used to get it from nsecs, see busy_loop_current_time(), so it's easy to get truncated nsec back and we get back better precision. Note, we can further improve it later by removing the truncation and maybe convincing net/ to use ktime/ns instead. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/95e7ec8d095069a3ed5d40a4bc6f8b586698bc7e.1722003776.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring: don't allow netpolling with SETUP_IOPOLLPavel Begunkov2024-07-241-0/+2
| | | | | | | | | | | | IORING_SETUP_IOPOLL rings don't have any netpoll handling, let's fail attempts to register netpolling in this case, there might be people who will mix up IOPOLL and netpoll. Cc: stable@vger.kernel.org Fixes: ef1186c1a875b ("io_uring: add register/unregister napi function") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1e7553aee0a8ae4edec6742cd6dd0c1e6914fba8.1721819383.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring/napi: Remove unnecessary s64 castThorsten Blum2024-07-101-1/+1
| | | | | | | | | | | | Since the do_div() macro casts the divisor to u32 anyway, remove the unnecessary s64 cast and fix the following Coccinelle/coccicheck warning reported by do_div.cocci: WARNING: do_div() does a 64-by-32 division, please consider using div64_s64 instead Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Link: https://lore.kernel.org/r/20240710010520.384009-2-thorsten.blum@toblux.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring/napi: fix timeout calculationJens Axboe2024-06-041-11/+13
| | | | | | | | | | | | | | | | | | | | | | | | Not quite sure what __io_napi_adjust_timeout() was attemping to do, it's adjusting both the NAPI timeout and the general overall timeout, and calculating a value that is never used. The overall timeout is a super set of the NAPI timeout, and doesn't need adjusting. The only thing we really need to care about is that the NAPI timeout doesn't exceed the overall timeout. If a user asked for a timeout of eg 5 usec and NAPI timeout is 10 usec, then we should not spin for 10 usec. While in there, sanitize the time checking a bit. If we have a negative value in the passed in timeout, discard it. Round up the value as well, so we don't end up with a NAPI timeout for the majority of the wait, with only a tiny sleep value at the end. Hence the only case we need to care about is if the NAPI timeout is larger than the overall timeout. If it is, cap the NAPI timeout at what the overall timeout is. Cc: stable@vger.kernel.org Fixes: 8d0c12a80cde ("io-uring: add napi busy poll support") Reported-by: Lewis Baker <lewissbaker@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring/napi: enable even with a timeout of 0Jens Axboe2024-02-151-4/+5
| | | | | | | | | | | | | | 1 usec is not as short as it used to be, and it makes sense to allow 0 for a busy poll timeout - this means just do one loop to check if we have anything available. Add a separate ->napi_enabled to check if napi has been enabled or not. While at it, move the writing of the ctx napi values after we've copied the old values back to userspace. This ensures that if the call fails, we'll be in the same state as we were before, rather than some indeterminate state. Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io_uring/napi: ensure napi polling is aborted when work is availableJens Axboe2024-02-141-1/+1
| | | | | | | | | | | | | | 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>
* io_uring: add register/unregister napi functionStefan Roesch2024-02-091-0/+52
| | | | | | | | | | | | This adds an api to register and unregister the napi for io-uring. If the arg value is specified when unregistering, the current napi setting for the busy poll timeout is copied into the user structure. If this is not required, NULL can be passed as the arg value. Signed-off-by: Stefan Roesch <shr@devkernel.io> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20230608163839.2891748-7-shr@devkernel.io Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io-uring: add sqpoll support for napi busy pollStefan Roesch2024-02-091-0/+24
| | | | | | | | | This adds the sqpoll support to the io-uring napi. Signed-off-by: Stefan Roesch <shr@devkernel.io> Suggested-by: Olivier Langlois <olivier@trillion01.com> Link: https://lore.kernel.org/r/20230608163839.2891748-6-shr@devkernel.io Signed-off-by: Jens Axboe <axboe@kernel.dk>
* io-uring: add napi busy poll supportStefan Roesch2024-02-091-0/+255
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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