* [PATCH liburing v2 1/2] io_uring_enter: add timeout support
2020-08-04 9:21 [PATCH liburing v2 0/2] add support for new timeout feature Jiufei Xue
@ 2020-08-04 9:21 ` Jiufei Xue
2020-08-04 10:25 ` Stefan Metzmacher
2020-08-04 9:21 ` [PATCH liburing v2 2/2] test/timeout: add testcase for new timeout feature Jiufei Xue
1 sibling, 1 reply; 7+ messages in thread
From: Jiufei Xue @ 2020-08-04 9:21 UTC (permalink / raw)
To: axboe; +Cc: io-uring, metze, Jiufei Xue
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 <[email protected]>
---
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
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH liburing v2 2/2] test/timeout: add testcase for new timeout feature
2020-08-04 9:21 [PATCH liburing v2 0/2] add support for new timeout feature Jiufei Xue
2020-08-04 9:21 ` [PATCH liburing v2 1/2] io_uring_enter: add timeout support Jiufei Xue
@ 2020-08-04 9:21 ` Jiufei Xue
1 sibling, 0 replies; 7+ messages in thread
From: Jiufei Xue @ 2020-08-04 9:21 UTC (permalink / raw)
To: axboe; +Cc: io-uring, metze, Jiufei Xue
Signed-off-by: Jiufei Xue <[email protected]>
---
test/Makefile | 1 +
test/timeout.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 98 insertions(+)
diff --git a/test/Makefile b/test/Makefile
index a693d6f..8892ee9 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -89,6 +89,7 @@ submit-reuse: XCFLAGS = -lpthread
poll-v-poll: XCFLAGS = -lpthread
across-fork: XCFLAGS = -lpthread
ce593a6c480a-test: XCFLAGS = -lpthread
+timeout: XCFLAGS = -lpthread
install: $(all_targets) runtests.sh runtests-loop.sh
$(INSTALL) -D -d -m 755 $(datadir)/liburing-test/
diff --git a/test/timeout.c b/test/timeout.c
index 7e9f11d..008acc5 100644
--- a/test/timeout.c
+++ b/test/timeout.c
@@ -10,6 +10,7 @@
#include <string.h>
#include <fcntl.h>
#include <sys/time.h>
+#include <pthread.h>
#include "liburing.h"
#include "../src/syscall.h"
@@ -18,6 +19,11 @@
static int not_supported;
static int no_modify;
+struct thread_data {
+ struct io_uring *ring;
+ volatile int do_exit;
+};
+
static void msec_to_ts(struct __kernel_timespec *ts, unsigned int msec)
{
ts->tv_sec = msec / 1000;
@@ -232,6 +238,91 @@ err:
return 1;
}
+static void *test_reap_thread_fn(void *__data)
+{
+ struct thread_data *data = __data;
+ struct io_uring *ring = (struct io_uring *)data->ring;
+ struct io_uring_cqe *cqe;
+ struct __kernel_timespec ts;
+ int ret, i = 0;
+
+ msec_to_ts(&ts, TIMEOUT_MSEC);
+ while (!data->do_exit) {
+ ret = io_uring_wait_cqes(ring, &cqe, 2, &ts, NULL);
+ if (ret == -ETIME) {
+ if (i == 2)
+ break;
+ else
+ continue;
+ } else if (ret < 0) {
+ fprintf(stderr, "%s: wait timeout failed: %d\n", __FUNCTION__, ret);
+ goto err;
+ }
+ ret = cqe->res;
+ if (ret < 0) {
+ fprintf(stderr, "res: %d\n", ret);
+ goto err;
+ }
+
+ io_uring_cqe_seen(ring, cqe);
+ i++;
+ }
+
+ if (i != 2) {
+ fprintf(stderr, "got %d completions\n", i);
+ ret = 1;
+ goto err;
+ }
+ return NULL;
+
+err:
+ return (void *)(intptr_t)ret;
+}
+
+static int test_single_timeout_wait_new(struct io_uring *ring)
+{
+ struct thread_data data;
+ struct io_uring_sqe *sqe;
+ pthread_t reap_thread;
+ int ret;
+ void *retval;
+
+ if (!(ring->features & IORING_FEAT_GETEVENTS_TIMEOUT)) {
+ fprintf(stdout, "feature IORING_FEAT_GETEVENTS_TIMEOUT not supported.\n");
+ return 0;
+ }
+ if (io_uring_set_cqwait_timeout(ring)) {
+ fprintf(stdout, "o_uring_set_cqwait_timeout failed.\n");
+ return 1;
+ }
+
+ data.ring = ring;
+ data.do_exit = 0;
+
+ sqe = io_uring_get_sqe(ring);
+ io_uring_prep_nop(sqe);
+ io_uring_sqe_set_data(sqe, (void *) 1);
+
+ sqe = io_uring_get_sqe(ring);
+ io_uring_prep_nop(sqe);
+ io_uring_sqe_set_data(sqe, (void *) 1);
+
+ pthread_create(&reap_thread, NULL, test_reap_thread_fn, &data);
+
+ ret = io_uring_submit(ring);
+ if (ret <= 0) {
+ fprintf(stderr, "%s: sqe submit failed: %d\n", __FUNCTION__, ret);
+ goto err;
+ }
+
+ sleep(1);
+ data.do_exit = 1;
+ pthread_join(reap_thread, &retval);
+ return (int)(intptr_t)retval;
+err:
+ return 1;
+}
+
/*
* Test single timeout waking us up
*/
@@ -1054,6 +1145,12 @@ int main(int argc, char *argv[])
return ret;
}
+ ret = test_single_timeout_wait_new(&ring);
+ if (ret) {
+ fprintf(stderr, "test_single_timeout_wait_new failed\n");
+ return ret;
+ }
+
/*
* this test must go last, it kills the ring
*/
--
1.8.3.1
^ permalink raw reply related [flat|nested] 7+ messages in thread