diff options
| -rw-r--r-- | man/io_uring_register.2 | 47 |
1 files changed, 23 insertions, 24 deletions
diff --git a/man/io_uring_register.2 b/man/io_uring_register.2 index 1822fd3..7c156dc 100644 --- a/man/io_uring_register.2 +++ b/man/io_uring_register.2 @@ -13,7 +13,7 @@ io_uring_register \- register files or user buffers for asynchronous I/O .BR "#include <linux/io_uring.h>" .PP .BI "int io_uring_register(unsigned int " fd ", unsigned int " opcode , -.BI " void *" arg ", unsigned int " nr_args) +.BI " void *" arg ", unsigned int " nr_args ); .fi .PP .SH DESCRIPTION @@ -24,7 +24,7 @@ The system call registers user buffers or files for use in an .BR io_uring (7) instance referenced by -.I fd. +.IR fd . Registering files or user buffers allows the kernel to take long term references to internal data structures or create long term mappings of application memory, greatly reducing per-I/O overhead. @@ -36,7 +36,7 @@ is the file descriptor returned by a call to can be one of: .TP -.BR IORING_REGISTER_BUFFERS +.B IORING_REGISTER_BUFFERS .I arg points to a .I struct iovec @@ -44,7 +44,8 @@ array of .I nr_args entries. The buffers associated with the iovecs will be locked in memory and charged against the user's -.B RLIMIT_MEMLOCK resource limit. See +.B RLIMIT_MEMLOCK +resource limit. See .BR getrlimit (2) for more information. Additionally, there is a size limit of 1GiB per buffer. Currently, the buffers must be anonymous, non-file-backed @@ -91,14 +92,14 @@ with the new buffers. An application need not unregister buffers explicitly before shutting down the io_uring instance. .TP -.BR IORING_UNREGISTER_BUFFERS +.B IORING_UNREGISTER_BUFFERS This operation takes no argument, and .I arg must be passed as NULL. All previously registered buffers associated with the io_uring instance will be released. .TP -.BR IORING_REGISTER_FILES +.B IORING_REGISTER_FILES Register files for I/O. .I arg contains a pointer to an array of @@ -110,7 +111,7 @@ To make use of the registered files, the flag must be set in the .I flags member of the -.I struct io_uring_sqe, +.IR "struct io_uring_sqe" , and the .I fd member is set to the index of the file in the file descriptor array. @@ -119,7 +120,7 @@ Files are automatically unregistered when the io_uring instance is torn down. An application need only unregister if it wishes to register a new set of fds. .TP -.BR IORING_UNREGISTER_FILES +.B IORING_UNREGISTER_FILES This operation requires no argument, and .I arg must be passed as NULL. All previously registered files associated @@ -141,9 +142,9 @@ One or more fds in the array are invalid. .TP .B EBUSY -.BR IORING_REGISTER_BUFFERS +.B IORING_REGISTER_BUFFERS or -.BR IORING_REGISTER_FILES +.B IORING_REGISTER_FILES was specified, but there were already buffers or files registered. .TP .B EFAULT @@ -152,24 +153,24 @@ buffer is outside of the process' accessible address space, or is greater than 1GiB. .TP .B EINVAL -.BR IORING_REGISTER_BUFFERS +.B IORING_REGISTER_BUFFERS or -.BR IORING_REGISTER_FILES +.B IORING_REGISTER_FILES was specified, but .I nr_args is 0. .TP .B EINVAL -.BR IORING_REGISTER_BUFFERS +.B IORING_REGISTER_BUFFERS was specified, but .I nr_args exceeds -.BR UIO_MAXIOV +.B UIO_MAXIOV .TP .B EINVAL -.BR IORING_UNREGISTER_BUFFERS +.B IORING_UNREGISTER_BUFFERS or -.BR IORING_UNREGISTER_FILES +.B IORING_UNREGISTER_FILES was specified, and .I nr_args is non-zero or @@ -177,13 +178,13 @@ is non-zero or is non-NULL. .TP .B EMFILE -.BR IORING_REGISTER_FILES +.B IORING_REGISTER_FILES was specified and .I nr_args exceeds the maximum allowed number of files in a fixed file set. .TP .B EMFILE -.BR IORING_REGISTER_FILES +.B IORING_REGISTER_FILES was specified and adding .I nr_args file references would exceed the maximum allowed number of files the user @@ -197,17 +198,15 @@ capability. Note that this is a per user limit, not per process. .B ENOMEM Insufficient kernel resources are available, or the caller had a non-zero -.BR RLIMIT_MEMLOCK +.B RLIMIT_MEMLOCK soft resource limit, but tried to lock more memory than the limit permitted. This limit is not enforced if the process is privileged -( -.BR CAP_IPC_LOCK -). +.RB ( CAP_IPC_LOCK ). .TP .B ENXIO -.BR IORING_UNREGISTER_BUFFERS +.B IORING_UNREGISTER_BUFFERS or -.BR IORING_UNREGISTER_FILES +.B IORING_UNREGISTER_FILES was specified, but there were no buffers or files registered. .TP .B ENXIO |