Kernel can handle timeout when feature IORING_FEAT_GETEVENTS_TIMEOUT
supported. Add two new interfaces: io_uring_wait_cqes2(),
io_uring_wait_cqe_timeout2() for applications to use this feature.
Signed-off-by: Jiufei Xue <jiufei.xue@xxxxxxxxxxxxxxxxx>
---
src/include/liburing.h | 11 ++++--
src/include/liburing/io_uring.h | 2 ++
src/liburing.map | 3 ++
src/queue.c | 75 ++++++++++++++++++++++++++++++++++++++---
src/setup.c | 1 +
src/syscall.c | 4 +--
src/syscall.h | 2 +-
7 files changed, 88 insertions(+), 10 deletions(-)
diff --git a/src/include/liburing.h b/src/include/liburing.h
index 0505a4f..6176a63 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -56,6 +56,7 @@ struct io_uring {
struct io_uring_sq sq;
struct io_uring_cq cq;
unsigned flags;
+ unsigned features;
int ring_fd;
};
@@ -93,6 +94,11 @@ 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_wait_cqes2(struct io_uring *ring,
+ struct io_uring_cqe **cqe_ptr, unsigned wait_nr,
+ struct __kernel_timespec *ts, sigset_t *sigmask);
+extern int io_uring_wait_cqe_timeout2(struct io_uring *ring,
+ struct io_uring_cqe **cqe_ptr, struct __kernel_timespec *ts);
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);
@@ -120,7 +126,8 @@ 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)
@@ -491,7 +498,7 @@ 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..28f81e2 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
diff --git a/src/liburing.map b/src/liburing.map
index 38bd558..15c5f9d 100644
--- a/src/liburing.map
+++ b/src/liburing.map
@@ -56,4 +56,7 @@ LIBURING_0.6 {
} LIBURING_0.5;
LIBURING_0.7 {
+ global:
+ io_uring_wait_cqe_timeout2;
+ io_uring_wait_cqes2;
} LIBURING_0.6;
diff --git a/src/queue.c b/src/queue.c
index be80d7a..cdd6a15 100644
--- a/src/queue.c
+++ b/src/queue.c
@@ -65,11 +65,16 @@ 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 {
+ sigset_t *sigmask;
+ struct __kernel_timespec *ts;
+ } arg, *argp;
do {
bool cq_overflow_flush = false;
@@ -87,13 +92,26 @@ 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;
+ memset(argp, 0, sizeof(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) {
@@ -230,7 +248,7 @@ int io_uring_wait_cqes(struct io_uring *ring, struct io_uring_cqe **cqe_ptr,
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);
}
/*
@@ -245,6 +263,53 @@ int io_uring_wait_cqe_timeout(struct io_uring *ring,
}
/*
+ * If feature IORING_FEAT_GETEVENTS_TIMEOUT supported, this interface is
+ * safe for applications that split SQ and CQ handling in two threads.
+ * Applications need to call io_uring_submit() to submit the requests
+ * first.
+ */
+int io_uring_wait_cqes2(struct io_uring *ring, struct io_uring_cqe **cqe_ptr,
+ unsigned wait_nr, struct __kernel_timespec *ts,
+ sigset_t *sigmask)
+{
+ unsigned to_submit = 0;
+
+ if (ts && !(ring->features & IORING_FEAT_GETEVENTS_TIMEOUT)) {
+ 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;
+ 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;
+ to_submit = __io_uring_flush_sq(ring);
+ }
+
+ return __io_uring_get_cqe(ring, cqe_ptr, to_submit, wait_nr, ts, sigmask);
+}
+
+/*
+ * See io_uring_wait_cqes2() - this function is the same, it just always uses
+ * '1' as the wait_nr.
+ */
+int io_uring_wait_cqe_timeout2(struct io_uring *ring,
+ struct io_uring_cqe **cqe_ptr,
+ struct __kernel_timespec *ts)
+{
+ return io_uring_wait_cqes2(ring, cqe_ptr, 1, ts, NULL);
+}
+
+/*
* Submit sqes acquired from io_uring_get_sqe() to the kernel.
*
* Returns number of sqes submitted
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
