io_uring: make io_do_iopoll return number of reqs
Don't pass nr_events pointer around but return directly, it's less
expensive than pointer increments.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f771a8153a86f16f12ff4272524e9e549c5de40b.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index d605954..27ca4fb 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2425,8 +2425,7 @@ static inline bool io_run_task_work(void)
/*
* Find and free completed poll iocbs
*/
-static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
- struct list_head *done)
+static void io_iopoll_complete(struct io_ring_ctx *ctx, struct list_head *done)
{
struct req_batch rb;
struct io_kiocb *req;
@@ -2441,7 +2440,6 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
__io_cqring_fill_event(ctx, req->user_data, req->result,
io_put_rw_kbuf(req));
- (*nr_events)++;
if (req_ref_put_and_test(req))
io_req_free_batch(&rb, req, &ctx->submit_state);
@@ -2452,12 +2450,12 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
io_req_free_batch_finish(ctx, &rb);
}
-static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
- bool force_nonspin)
+static int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin)
{
struct io_kiocb *req, *tmp;
unsigned int poll_flags = BLK_POLL_NOSLEEP;
DEFINE_IO_COMP_BATCH(iob);
+ int nr_events = 0;
LIST_HEAD(done);
/*
@@ -2478,6 +2476,7 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
*/
if (READ_ONCE(req->iopoll_completed)) {
list_move_tail(&req->inflight_entry, &done);
+ nr_events++;
continue;
}
if (!list_empty(&done))
@@ -2491,16 +2490,18 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
/* iopoll may have completed current req */
if (!rq_list_empty(iob.req_list) ||
- READ_ONCE(req->iopoll_completed))
+ READ_ONCE(req->iopoll_completed)) {
list_move_tail(&req->inflight_entry, &done);
+ nr_events++;
+ }
}
if (!rq_list_empty(iob.req_list))
iob.complete(&iob);
if (!list_empty(&done))
- io_iopoll_complete(ctx, nr_events, &done);
+ io_iopoll_complete(ctx, &done);
- return 0;
+ return nr_events;
}
/*
@@ -2514,12 +2515,8 @@ static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
mutex_lock(&ctx->uring_lock);
while (!list_empty(&ctx->iopoll_list)) {
- unsigned int nr_events = 0;
-
- io_do_iopoll(ctx, &nr_events, true);
-
/* let it sleep and repeat later if can't complete a request */
- if (nr_events == 0)
+ if (io_do_iopoll(ctx, true) == 0)
break;
/*
* Ensure we allow local-to-the-cpu processing to take place,
@@ -2578,8 +2575,12 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
list_empty(&ctx->iopoll_list))
break;
}
- ret = io_do_iopoll(ctx, &nr_events, !min);
- } while (!ret && nr_events < min && !need_resched());
+ ret = io_do_iopoll(ctx, !min);
+ if (ret < 0)
+ break;
+ nr_events += ret;
+ ret = 0;
+ } while (nr_events < min && !need_resched());
out:
mutex_unlock(&ctx->uring_lock);
return ret;
@@ -7339,7 +7340,6 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
to_submit = IORING_SQPOLL_CAP_ENTRIES_VALUE;
if (!list_empty(&ctx->iopoll_list) || to_submit) {
- unsigned nr_events = 0;
const struct cred *creds = NULL;
if (ctx->sq_creds != current_cred())
@@ -7347,7 +7347,7 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
mutex_lock(&ctx->uring_lock);
if (!list_empty(&ctx->iopoll_list))
- io_do_iopoll(ctx, &nr_events, true);
+ io_do_iopoll(ctx, true);
/*
* Don't submit if refs are dying, good for io_uring_register(),