HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. |  |
NAME |SYNOPSIS |DESCRIPTION |RETURN VALUE |SEE ALSO |COLOPHON | |
io_uring_su...min_timeout(3) liburing Manualio_uring_su...min_timeout(3)io_uring_submit_and_wait_min_timeout - submit requests to the submission queue and wait for the completion with both batch and normal timeout
#include <liburing.h>int io_uring_submit_and_wait_min_timeout(struct io_uring *ring,struct io_uring_cqe **cqe_ptr,unsignedwait_nr,struct __kernel_timespec *ts,unsigned intmin_wait_usec,sigset_t *sigmask);
Theio_uring_submit_and_wait_min_timeout(3) function submits the next requests from the submission queue belonging to thering and waits forwait_nr completion events, or until the timeoutts expires. The completion events are stored in thecqe_ptr array. If non-zero,min_wait_usec denotes a timeout for thewait_nr batch. Thesigmask specifies the set of signals to block. If set, it is equivalent to atomically executing the following calls: sigset_t origmask; pthread_sigmask(SIG_SETMASK, &sigmask, &origmask); ret = io_uring_submit_and_wait_min_timeout(ring, cqe, wait_nr, ts, min_wait, NULL); pthread_sigmask(SIG_SETMASK, &origmask, NULL); This works likeio_uring_submit_and_wait_timeout(3) with the twist that it applies a minimum timeout for the requested batch size of requests to wait for. Whileio_uring_submit_and_wait_timeout(3) waits for as long asts specifies, or untilwait_nr of request completions have been received, ifmin_wait_usec is set, then this is the timeout for thewait_nr number of requests. If the requested number of completions have been received withinmin_wait_usec number of microseconds, then the function returns successfully. If that isn't the case, oncemin_wait_usec time has passed, control is returned if any completions have been posted. If no completions have been posted, the kernel switches to a normal wait of up tots specified amount of time, subtracting the time already waited. If any completions are posted after this happens, control is returned immediately to the application. This differs from the normal timeout waiting in that waiting continues post the initial timeout, if and only if no completions have been posted. It's meant to be used to optimize batch waiting for requests, where the application allots a budget ofmin_wait_usec amount of time to receivewait_nr number of completions, but if none are received, then waiting can continue without incurring extra context switches or extra kernel/user transitions. Can be used with any ring, as long as the kernel supports it. Support is indicated by checking theIORING_FEAT_MIN_TIMEOUT feature flag after the ring has been setup. Ideally used with a ring setup withIORING_SETUP_SINGLE_ISSUER|IORING_SETUP_DEFER_TASKRUNas that will greatly reduce the number of context switches that an application will see waiting on multiple requests. Available since 6.12.
On successio_uring_submit_and_wait_min_timeout(3) returns the number of submitted submission queue entries. On failure it returns-errno. If the kernel doesn't support this functionality,-EINVALwill be returned. See note on the feature flag. The most common failure case is not receiving a completion within the specified timeout,-ETIMEis returned in this case.
io_uring_queue_init_params(3),io_uring_get_sqe(3),io_uring_submit(3),io_uring_submit_and_wait(3),io_uring_submit_and_wait_timeout(3),io_uring_wait_cqe(3)
This page is part of theliburing (A library for io_uring) project. Information about the project can be found at ⟨https://github.com/axboe/liburing⟩. If you have a bug report for this manual page, send it to io-uring@vger.kernel.org. This page was obtained from the project's upstream Git repository ⟨https://github.com/axboe/liburing⟩ on 2025-08-11. (At that time, the date of the most recent commit that was found in the repository was 2025-08-02.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which isnot part of the original manual page), send a mail to man-pages@man7.orgliburing-2.8 Jan 11, 2024io_uring_su...min_timeout(3)Pages that refer to this page:io_uring_setup(2), io_uring_submit_and_wait_min_timeout(3), io_uring_submit_and_wait_reg(3), io_uring_wait_cqes_min_timeout(3)
HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. | |