After consulting Paolo I know why we'd better keep the explicit
aio_poll() in iothread_run(). Document it directly into the code so
that future readers will know the answer from day one.
Signed-off-by: Peter Xu <pet...@redhat.com>
---
iothread.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/iothread.c b/iothread.c
index 045825a348..14e9f3779e 100644
--- a/iothread.c
+++ b/iothread.c
@@ -64,6 +64,15 @@ static void *iothread_run(void *opaque)
qemu_sem_post(&iothread->init_done_sem);
while (iothread->running) {
+ /*
+ * Note: from functional-wise the g_main_loop_run() below can
+ * already cover the aio_poll() events, but we can't run the
+ * main loop unconditionally because explicit aio_poll() here
+ * is faster than g_main_loop_run() when we do not need the
+ * gcontext at all (e.g., pure block layer iothreads). In
+ * other words, when we want to run the gcontext with the
+ * iothread we need to pay some performance for functionality.
+ */
aio_poll(iothread->ctx, true);
/*
--
2.17.1
