From 7797158ea67304507f9811741e9f00dff5858974 Mon Sep 17 00:00:00 2001
From: Max Kellermann <max.kellermann@ionos.com>
Date: Fri, 21 Feb 2025 16:08:43 +0100
Subject: [PATCH] event/Loop: auto-restart io_uring_prep_poll_multishot()

Applications need to check the `IORING_CQE_F_MORE` flag to see whether
the kernel is still polling, or whether it has stopped for some reason.
---
 src/event/Loop.cxx | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/event/Loop.cxx b/src/event/Loop.cxx
index e9716649f..c4962a8d0 100644
--- a/src/event/Loop.cxx
+++ b/src/event/Loop.cxx
@@ -75,6 +75,12 @@ private:
 		(void)res; // TODO
 
 		event_loop.epoll_ready = true;
+
+		if (!IsUringPending()) [[unlikely]]
+			/* for some reason, the kernel has stopped our
+			   poll operation (no IORING_CQE_F_MORE):
+			   restart the poll */
+			Start();
 	}
 };