Subject: [RFC PATCH v1 1/3] liburing: add api to set napi busy poll timeout

From: Stefan Roesch <[email-masked]>
Date: Thu, 3 Nov 2022 13:40:15 -0700

This adds the two functions to register and unregister the napi busy
poll timeout:
- io_uring_register_busy_poll_timeout
- io_uring_unregister_busy_poll_timeout

Signed-off-by: Stefan Roesch <[email-masked]>
---
 src/include/liburing.h          |  3 +++
 src/include/liburing/io_uring.h |  4 ++++
 src/register.c                  | 12 ++++++++++++
 3 files changed, 19 insertions(+)

diff --git a/src/include/liburing.h b/src/include/liburing.h
index 12a703f..ef2510e 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -235,6 +235,9 @@ int io_uring_register_sync_cancel(struct io_uring *ring,
 int io_uring_register_file_alloc_range(struct io_uring *ring,
 					unsigned off, unsigned len);
 
+int io_uring_register_busy_poll_timeout(struct io_uring *ring, unsigned int to);
+int io_uring_unregister_busy_poll_timeout(struct io_uring *ring);
+
 int io_uring_get_events(struct io_uring *ring);
 int io_uring_submit_and_get_events(struct io_uring *ring);
 
diff --git a/src/include/liburing/io_uring.h b/src/include/liburing/io_uring.h
index a3e0920..0919d9e 100644
--- a/src/include/liburing/io_uring.h
+++ b/src/include/liburing/io_uring.h
@@ -499,6 +499,10 @@ enum {
 	/* register a range of fixed file slots for automatic slot allocation */
 	IORING_REGISTER_FILE_ALLOC_RANGE	= 25,
 
+	/* set/clear busy poll timeout */
+	IORING_REGISTER_NAPI_BUSY_POLL_TIMEOUT	= 26,
+	IORING_UNREGISTER_NAPI_BUSY_POLL_TIMEOUT= 27,
+
 	/* this goes last */
 	IORING_REGISTER_LAST
 };
diff --git a/src/register.c b/src/register.c
index e849825..c18e072 100644
--- a/src/register.c
+++ b/src/register.c
@@ -367,3 +367,15 @@ int io_uring_register_file_alloc_range(struct io_uring *ring,
 				       IORING_REGISTER_FILE_ALLOC_RANGE, &range,
 				       0);
 }
+
+int io_uring_register_busy_poll_timeout(struct io_uring *ring, unsigned int to)
+{
+	return __sys_io_uring_register(ring->ring_fd,
+				IORING_REGISTER_NAPI_BUSY_POLL_TIMEOUT, NULL, to);
+}
+
+int io_uring_unregister_busy_poll_timeout(struct io_uring *ring)
+{
+	return __sys_io_uring_register(ring->ring_fd,
+				IORING_UNREGISTER_NAPI_BUSY_POLL_TIMEOUT, NULL, 0);
+}
-- 
2.30.2