While testing io_uring NAPI with DEFER_TASKRUN, I ran into slowdowns and
stalls in packet delivery. Turns out that while
io_napi_busy_loop_should_end() aborts appropriately on regular
task_work, it does not abort if we have local task_work pending.
Move io_has_work() into the private io_uring.h header, and gate whether
we should continue polling on that as well. This makes NAPI polling on
send/receive work as designed with IORING_SETUP_DEFER_TASKRUN as well.
Fixes: 8d0c12a80cde ("io-uring: add napi busy poll support")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
#define IO_COMPL_BATCH 32
#define IO_REQ_ALLOC_BATCH 8
-enum {
- IO_CHECK_CQ_OVERFLOW_BIT,
- IO_CHECK_CQ_DROPPED_BIT,
-};
-
struct io_defer_entry {
struct list_head list;
struct io_kiocb *req;
return ret;
}
-static inline bool io_has_work(struct io_ring_ctx *ctx)
-{
- return test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq) ||
- !llist_empty(&ctx->work_llist);
-}
-
static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
int wake_flags, void *key)
{
}
return false;
}
+
+enum {
+ IO_CHECK_CQ_OVERFLOW_BIT,
+ IO_CHECK_CQ_DROPPED_BIT,
+};
+
+static inline bool io_has_work(struct io_ring_ctx *ctx)
+{
+ return test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq) ||
+ !llist_empty(&ctx->work_llist);
+}
#endif
if (signal_pending(current))
return true;
- if (io_should_wake(iowq))
+ if (io_should_wake(iowq) || io_has_work(iowq->ctx))
return true;
if (io_napi_busy_loop_timeout(start_time, iowq->napi_busy_poll_to))
return true;