[PATCH 2/9] io_uring: keep track of overflow entry count

[Jens Axboe <axboe@xxxxxxxxx>]

Not needed just yet, but in preparation for factoring these in for the
wakeup batching.

Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
 include/linux/io_uring_types.h | 1 +
 io_uring/io_uring.c            | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index a2227ab7fd16..d795f3f3a705 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -325,6 +325,7 @@ struct io_ring_ctx {
 		unsigned long		check_cq;
 		atomic_t		cq_wait_nr;
 		atomic_t		cq_timeouts;
+		int			nr_overflow;
 		struct wait_queue_head	cq_wait;
 	} ____cacheline_aligned_in_smp;
 
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 96f6da0bf5cd..94af56dd5344 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -618,6 +618,7 @@ static void __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool dying)
 			memcpy(cqe, &ocqe->cqe, cqe_size);
 		}
 		list_del(&ocqe->list);
+		ctx->nr_overflow--;
 		kfree(ocqe);
 	}
 
@@ -724,6 +725,7 @@ static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data,
 		ocqe->cqe.big_cqe[0] = extra1;
 		ocqe->cqe.big_cqe[1] = extra2;
 	}
+	ctx->nr_overflow++;
 	list_add_tail(&ocqe->list, &ctx->cq_overflow_list);
 	return true;
 }
-- 
2.43.0