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>
This commit is contained in:
Pavel Begunkov 2021-09-24 21:59:43 +01:00 committed by Jens Axboe
parent 87a115fb71
commit 5ba3c874eb

View File

@ -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(),