From 996b5a65a58cfd3334fcc6c268911126ced35d61 Mon Sep 17 00:00:00 2001 From: Jeff Moyer Date: Fri, 8 Feb 2019 14:54:02 -0500 Subject: add io_uring_queue_mmap io_uring_queue_init does not allow the caller to specify sq_thread_cpu or sq_thread_idle. Users that want to specify those parameters need to call io_uring_setup(2) themselves. Add a helper so that they don't also have to hand-craft the code to map the submission and completion queues, and setup the sqe ring. This allows those applications to still make use of io_uring_submit and get/wait_completion. Signed-off-by: Jeff Moyer Signed-off-by: Jens Axboe --- src/liburing.h | 2 ++ src/setup.c | 25 +++++++++++++++++++------ 2 files changed, 21 insertions(+), 6 deletions(-) (limited to 'src') diff --git a/src/liburing.h b/src/liburing.h index 623556a..2e7303c 100644 --- a/src/liburing.h +++ b/src/liburing.h @@ -56,6 +56,8 @@ extern int io_uring_register(int fd, unsigned int opcode, void *arg, */ extern int io_uring_queue_init(unsigned entries, struct io_uring *ring, unsigned flags); +extern int io_uring_queue_mmap(int fd, struct io_uring_params *p, + struct io_uring *ring); extern void io_uring_queue_exit(struct io_uring *ring); extern int io_uring_get_completion(struct io_uring *ring, struct io_uring_cqe **cqe_ptr); diff --git a/src/setup.c b/src/setup.c index eeb5fef..9979dd0 100644 --- a/src/setup.c +++ b/src/setup.c @@ -57,6 +57,23 @@ err: return 0; } +/* + * For users that want to specify sq_thread_cpu or sq_thread_idle, this + * interface is a convenient helper for mmap()ing the rings. + * Returns -1 on error, or zero on success. On success, 'ring' + * contains the necessary information to read/write to the rings. + */ +int io_uring_queue_mmap(int fd, struct io_uring_params *p, struct io_uring *ring) +{ + int ret; + + memset(ring, 0, sizeof(*ring)); + ret = io_uring_mmap(fd, p, &ring->sq, &ring->cq); + if (!ret) + ring->ring_fd = fd; + return ret; +} + /* * Returns -1 on error, or zero on success. On success, 'ring' * contains the necessary information to read/write to the rings. @@ -64,7 +81,7 @@ err: int io_uring_queue_init(unsigned entries, struct io_uring *ring, unsigned flags) { struct io_uring_params p; - int fd, ret; + int fd; memset(&p, 0, sizeof(p)); p.flags = flags; @@ -73,11 +90,7 @@ int io_uring_queue_init(unsigned entries, struct io_uring *ring, unsigned flags) if (fd < 0) return fd; - memset(ring, 0, sizeof(*ring)); - ret = io_uring_mmap(fd, &p, &ring->sq, &ring->cq); - if (!ret) - ring->ring_fd = fd; - return ret; + return io_uring_queue_mmap(fd, &p, ring); } void io_uring_queue_exit(struct io_uring *ring) -- cgit