From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA1F4C433DF for ; Tue, 4 Aug 2020 09:22:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C241B22C9F for ; Tue, 4 Aug 2020 09:22:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729596AbgHDJWC (ORCPT ); Tue, 4 Aug 2020 05:22:02 -0400 Received: from out30-133.freemail.mail.aliyun.com ([115.124.30.133]:47367 "EHLO out30-133.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728629AbgHDJWC (ORCPT ); Tue, 4 Aug 2020 05:22:02 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01355;MF=jiufei.xue@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0U4jrkKc_1596532916; Received: from localhost(mailfrom:jiufei.xue@linux.alibaba.com fp:SMTPD_---0U4jrkKc_1596532916) by smtp.aliyun-inc.com(127.0.0.1); Tue, 04 Aug 2020 17:21:56 +0800 From: Jiufei Xue To: axboe@kernel.dk Cc: io-uring@vger.kernel.org, metze@samba.org, Jiufei Xue Subject: [PATCH liburing v2 1/2] io_uring_enter: add timeout support Date: Tue, 4 Aug 2020 17:21:52 +0800 Message-Id: <1596532913-70757-2-git-send-email-jiufei.xue@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1596532913-70757-1-git-send-email-jiufei.xue@linux.alibaba.com> References: <1596532913-70757-1-git-send-email-jiufei.xue@linux.alibaba.com> Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Kernel can handle timeout when feature IORING_FEAT_GETEVENTS_TIMEOUT supported. Applications should use io_uring_set_cqwait_timeout() explicitly to asked for the new feature. In addition in this commit we add two new members to io_uring and a pad for future flexibility. So for the next release, applications have to re-compile against the lib. Signed-off-by: Jiufei Xue --- src/include/liburing.h | 12 +++++- src/include/liburing/io_uring.h | 7 ++++ src/liburing.map | 2 + src/queue.c | 88 ++++++++++++++++++++++++++++++----------- src/setup.c | 1 + src/syscall.c | 4 +- src/syscall.h | 2 +- 7 files changed, 88 insertions(+), 28 deletions(-) diff --git a/src/include/liburing.h b/src/include/liburing.h index 0505a4f..a7e50c3 100644 --- a/src/include/liburing.h +++ b/src/include/liburing.h @@ -56,6 +56,9 @@ struct io_uring { struct io_uring_sq sq; struct io_uring_cq cq; unsigned flags; + unsigned flags_internal; + unsigned features; + unsigned pad; int ring_fd; }; @@ -93,6 +96,7 @@ extern int io_uring_wait_cqes(struct io_uring *ring, struct __kernel_timespec *ts, sigset_t *sigmask); extern int io_uring_wait_cqe_timeout(struct io_uring *ring, struct io_uring_cqe **cqe_ptr, struct __kernel_timespec *ts); +extern int io_uring_set_cqwait_timeout(struct io_uring *ring); extern int io_uring_submit(struct io_uring *ring); extern int io_uring_submit_and_wait(struct io_uring *ring, unsigned wait_nr); extern struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring); @@ -120,10 +124,14 @@ extern int io_uring_unregister_personality(struct io_uring *ring, int id); */ extern int __io_uring_get_cqe(struct io_uring *ring, struct io_uring_cqe **cqe_ptr, unsigned submit, - unsigned wait_nr, sigset_t *sigmask); + unsigned wait_nr, struct __kernel_timespec *ts, + sigset_t *sigmask); #define LIBURING_UDATA_TIMEOUT ((__u64) -1) +/* io_uring->flags_internal */ +#define IORING_FLAGS_GETEVENTS_TIMEOUT (1U << 0) /* use the feature FEAT_GETEVENTS_TIMEOUT */ + #define io_uring_for_each_cqe(ring, head, cqe) \ /* \ * io_uring_smp_load_acquire() enforces the order of tail \ @@ -491,7 +499,7 @@ static inline int io_uring_wait_cqe_nr(struct io_uring *ring, struct io_uring_cqe **cqe_ptr, unsigned wait_nr) { - return __io_uring_get_cqe(ring, cqe_ptr, 0, wait_nr, NULL); + return __io_uring_get_cqe(ring, cqe_ptr, 0, wait_nr, NULL, NULL); } /* diff --git a/src/include/liburing/io_uring.h b/src/include/liburing/io_uring.h index d39b45f..3af67f6 100644 --- a/src/include/liburing/io_uring.h +++ b/src/include/liburing/io_uring.h @@ -228,6 +228,7 @@ struct io_cqring_offsets { */ #define IORING_ENTER_GETEVENTS (1U << 0) #define IORING_ENTER_SQ_WAKEUP (1U << 1) +#define IORING_ENTER_GETEVENTS_TIMEOUT (1U << 2) /* * Passed in for io_uring_setup(2). Copied back with updated info on success @@ -255,6 +256,7 @@ struct io_uring_params { #define IORING_FEAT_CUR_PERSONALITY (1U << 4) #define IORING_FEAT_FAST_POLL (1U << 5) #define IORING_FEAT_POLL_32BITS (1U << 6) +#define IORING_FEAT_GETEVENTS_TIMEOUT (1U << 7) /* * io_uring_register(2) opcodes and arguments @@ -294,6 +296,11 @@ struct io_uring_probe { struct io_uring_probe_op ops[0]; }; +struct io_uring_getevents_arg { + sigset_t *sigmask; + struct __kernel_timespec *ts; +}; + #ifdef __cplusplus } #endif diff --git a/src/liburing.map b/src/liburing.map index 38bd558..457da19 100644 --- a/src/liburing.map +++ b/src/liburing.map @@ -56,4 +56,6 @@ LIBURING_0.6 { } LIBURING_0.5; LIBURING_0.7 { + global: + io_uring_set_cqwait_timeout; } LIBURING_0.6; diff --git a/src/queue.c b/src/queue.c index be80d7a..5ee6e90 100644 --- a/src/queue.c +++ b/src/queue.c @@ -65,11 +65,13 @@ static int __io_uring_peek_cqe(struct io_uring *ring, } int __io_uring_get_cqe(struct io_uring *ring, struct io_uring_cqe **cqe_ptr, - unsigned submit, unsigned wait_nr, sigset_t *sigmask) + unsigned submit, unsigned wait_nr, struct __kernel_timespec *ts, + sigset_t *sigmask) { struct io_uring_cqe *cqe = NULL; const int to_wait = wait_nr; int ret = 0, err; + struct io_uring_getevents_arg arg = {0}, *argp; do { bool cq_overflow_flush = false; @@ -87,13 +89,25 @@ int __io_uring_get_cqe(struct io_uring *ring, struct io_uring_cqe **cqe_ptr, } if (wait_nr && cqe) wait_nr--; - if (wait_nr || cq_overflow_flush) + if (wait_nr || cq_overflow_flush) { flags = IORING_ENTER_GETEVENTS; + if (ring->features & IORING_FEAT_GETEVENTS_TIMEOUT) + flags |= IORING_ENTER_GETEVENTS_TIMEOUT; + } if (submit) sq_ring_needs_enter(ring, submit, &flags); - if (wait_nr || submit || cq_overflow_flush) + if (wait_nr || submit || cq_overflow_flush) { + if (ring->features & IORING_FEAT_GETEVENTS_TIMEOUT) { + argp = &arg; + if (sigmask) + argp->sigmask = sigmask; + if (ts) + argp->ts = ts; + } else + argp = (void *)sigmask; ret = __sys_io_uring_enter(ring->ring_fd, submit, - wait_nr, flags, sigmask); + wait_nr, flags, (void *)argp); + } if (ret < 0) { err = -errno; } else if (ret == (int)submit) { @@ -194,14 +208,26 @@ out: /* * Like io_uring_wait_cqe(), except it accepts a timeout value as well. Note - * that an sqe is used internally to handle the timeout. Applications using + * that an sqe is used internally to handle the timeout when the feature + * IORING_FEAT_GETEVENTS_TIMEOUT is not supported. Applications using * this function must never set sqe->user_data to LIBURING_UDATA_TIMEOUT! * - * If 'ts' is specified, the application need not call io_uring_submit() before + * If 'ts' is specified and application hasn't told us to use the + * FEAT_GETEVENTS_TIMEOUT, there are two cases here: + * 1) kernel is not supported, an sqe is used internally to handle the + * timeout. Applications using this function must never set + * sqe->user_data to LIBURING_UDATA_TIMEOUT! + * 2) kernel is supported, we just flush existing submissions and use + * the feature FEAT_GETEVENTS_TIMEOUT. + * + * In the above cases, application needn't call io_uring_submit() before * calling this function, as we will do that on its behalf. From this it also * follows that this function isn't safe to use for applications that split SQ * and CQ handling between two threads and expect that to work without * synchronization, as this function manipulates both the SQ and CQ side. + * + * If the applications explicitly asked for the new feature, and the kernel + * is supported, this function will not manipulate the SQ side. */ int io_uring_wait_cqes(struct io_uring *ring, struct io_uring_cqe **cqe_ptr, unsigned wait_nr, struct __kernel_timespec *ts, @@ -209,28 +235,34 @@ int io_uring_wait_cqes(struct io_uring *ring, struct io_uring_cqe **cqe_ptr, { unsigned to_submit = 0; - if (ts) { - struct io_uring_sqe *sqe; - int ret; - - /* - * If the SQ ring is full, we may need to submit IO first - */ - sqe = io_uring_get_sqe(ring); - if (!sqe) { - ret = io_uring_submit(ring); - if (ret < 0) - return ret; + if (ts && (!(ring->flags_internal & IORING_FLAGS_GETEVENTS_TIMEOUT))) { + if (!(ring->features & IORING_FEAT_GETEVENTS_TIMEOUT)) { + /* + * prepare a timeout sqe internally when + * FEAT_GETEVENTS_TIMEOUT not supported. + */ + struct io_uring_sqe *sqe; + int ret; + + /* + * If the SQ ring is full, we may need to submit IO first + */ sqe = io_uring_get_sqe(ring); - if (!sqe) - return -EAGAIN; + if (!sqe) { + ret = io_uring_submit(ring); + if (ret < 0) + return ret; + sqe = io_uring_get_sqe(ring); + if (!sqe) + return -EAGAIN; + } + io_uring_prep_timeout(sqe, ts, wait_nr, 0); + sqe->user_data = LIBURING_UDATA_TIMEOUT; } - io_uring_prep_timeout(sqe, ts, wait_nr, 0); - sqe->user_data = LIBURING_UDATA_TIMEOUT; to_submit = __io_uring_flush_sq(ring); } - return __io_uring_get_cqe(ring, cqe_ptr, to_submit, wait_nr, sigmask); + return __io_uring_get_cqe(ring, cqe_ptr, to_submit, wait_nr, ts, sigmask); } /* @@ -244,6 +276,16 @@ int io_uring_wait_cqe_timeout(struct io_uring *ring, return io_uring_wait_cqes(ring, cqe_ptr, 1, ts, NULL); } +int io_uring_set_cqwait_timeout(struct io_uring *ring) +{ + /* Applications should aware of the feature */ + if (!(ring->features & IORING_FEAT_GETEVENTS_TIMEOUT)) + return -EINVAL; + + ring->flags_internal |= IORING_FLAGS_GETEVENTS_TIMEOUT; + return 0; +} + /* * Submit sqes acquired from io_uring_get_sqe() to the kernel. * diff --git a/src/setup.c b/src/setup.c index 2b17b94..b258cf1 100644 --- a/src/setup.c +++ b/src/setup.c @@ -96,6 +96,7 @@ int io_uring_queue_mmap(int fd, struct io_uring_params *p, struct io_uring *ring if (!ret) { ring->flags = p->flags; ring->ring_fd = fd; + ring->features = p->features; } return ret; } diff --git a/src/syscall.c b/src/syscall.c index c41e099..926700b 100644 --- a/src/syscall.c +++ b/src/syscall.c @@ -48,8 +48,8 @@ int __sys_io_uring_setup(unsigned entries, struct io_uring_params *p) } int __sys_io_uring_enter(int fd, unsigned to_submit, unsigned min_complete, - unsigned flags, sigset_t *sig) + unsigned flags, void *argp) { return syscall(__NR_io_uring_enter, fd, to_submit, min_complete, - flags, sig, _NSIG / 8); + flags, argp, _NSIG / 8); } diff --git a/src/syscall.h b/src/syscall.h index 7e299d4..b135d42 100644 --- a/src/syscall.h +++ b/src/syscall.h @@ -7,7 +7,7 @@ */ extern int __sys_io_uring_setup(unsigned entries, struct io_uring_params *p); extern int __sys_io_uring_enter(int fd, unsigned to_submit, - unsigned min_complete, unsigned flags, sigset_t *sig); + unsigned min_complete, unsigned flags, void *argp); extern int __sys_io_uring_register(int fd, unsigned int opcode, const void *arg, unsigned int nr_args); -- 1.8.3.1