@@ -38,6 +38,20 @@ static unsigned long long mtime_since_now(struct timeval *tv)
return mtime_since(tv, &end);
}
+static int register_memory(struct io_uring *ring, void *ptr, size_t size)
+{
+ struct io_uring_region_desc rd = {};
+ struct io_uring_mem_region_reg mr = {};
+
+ rd.user_addr = (__u64)(unsigned long)ptr;
+ rd.size = size;
+ rd.flags = IORING_MEM_REGION_TYPE_USER;
+ mr.region_uptr = (__u64)(unsigned long)&rd;
+ mr.flags = IORING_MEM_REGION_REG_WAIT_ARG;
+
+ return io_uring_register_region(ring, &mr);
+}
+
int main(int argc, char *argv[])
{
struct io_uring_reg_wait *reg;
@@ -48,30 +62,43 @@ int main(int argc, char *argv[])
unsigned long msec;
struct timeval tv;
int ret, fds[2];
+ int page_size;
if (argc > 1) {
fprintf(stdout, "%s: takes no arguments\n", argv[0]);
return 0;
}
+ page_size = sysconf(_SC_PAGESIZE);
+ if (page_size < 0) {
+ fprintf(stderr, "sysconf(_SC_PAGESIZE) failed\n");
+ return 1;
+ }
+
if (pipe(fds) < 0) {
perror("pipe");
return 1;
}
- ret = io_uring_queue_init(8, &ring, 0);
+ ret = io_uring_queue_init(8, &ring, IORING_SETUP_R_DISABLED);
if (ret) {
fprintf(stderr, "Queue init: %d\n", ret);
return 1;
}
/*
- * Setup wait region. We'll use 32 here, but 64 is probably a more
- * logical value, as it'll pin a page regardless of size. 64 is the
- * max value on a 4k page size architecture.
+ * Setup a region we'll use to pass wait arguments. It should be
+ * page aligned, we're using only first two wait entries here and
+ * the rest of the memory can be reused for other purposes.
*/
- reg = io_uring_setup_reg_wait(&ring, 32, &ret);
+ reg = aligned_alloc(page_size, page_size);
if (!reg) {
+ fprintf(stderr, "allocation failed\n");
+ return 1;
+ }
+
+ ret = register_memory(&ring, reg, page_size);
+ if (ret) {
if (ret == -EINVAL) {
fprintf(stderr, "Kernel doesn't support registered waits\n");
return 1;
@@ -80,6 +107,12 @@ int main(int argc, char *argv[])
return 1;
}
+ ret = io_uring_enable_rings(&ring);
+ if (ret) {
+ fprintf(stderr, "io_uring_enable_rings failure %i\n", ret);
+ return 1;
+ }
+
/*
* Setup two distinct wait regions. Index 0 will be a 1 second wait,
* and region 2 is a short wait using min_wait_usec as well. Neither
@@ -154,6 +187,6 @@ int main(int argc, char *argv[])
* Cleanup after ourselves
*/
io_uring_queue_exit(&ring);
- io_uring_free_reg_wait(reg, 32);
+ free(reg);
return 0;
}
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> --- examples/reg-wait.c | 45 +++++++++++++++++++++++++++++++++++++++------ 1 file changed, 39 insertions(+), 6 deletions(-)