[PATCH for-next 4/7] io_uring: refactor req allocation

Pavel Begunkov
2023-01-23T14:42:15Z

Follow the io_get_sqe pattern returning the result via a pointer
and hide request cache refill inside io_alloc_req().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
io_uring/io_uring.c | 7 +++----
io_uring/io_uring.h | 19 +++++++++++--------
io_uring/notif.c | 3 +--
3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 6af11a60dc8a..8a99791a507a 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2417,9 +2417,8 @@ int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
const struct io_uring_sqe *sqe;
struct io_kiocb *req;

- if (unlikely(!io_alloc_req_refill(ctx)))
+ if (unlikely(!io_alloc_req(ctx, &req)))
break;
- req = io_alloc_req(ctx);
if (unlikely(!io_get_sqe(ctx, &sqe))) {
io_req_add_to_cache(req, ctx);
break;
@@ -2738,14 +2737,14 @@ static int io_eventfd_unregister(struct io_ring_ctx *ctx)

static void io_req_caches_free(struct io_ring_ctx *ctx)
{
+ struct io_kiocb *req;
int nr = 0;

mutex_lock(&ctx->uring_lock);
io_flush_cached_locked_reqs(ctx, &ctx->submit_state);

while (!io_req_cache_empty(ctx)) {
- struct io_kiocb *req = io_alloc_req(ctx);
-
+ req = io_extract_req(ctx);
kmem_cache_free(req_cachep, req);
nr++;
}
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 3ee6fc74f020..1cc6c2a8696b 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -333,16 +333,9 @@ static inline bool io_req_cache_empty(struct io_ring_ctx *ctx)
return !ctx->submit_state.free_list.next;
}

-static inline bool io_alloc_req_refill(struct io_ring_ctx *ctx)
-{
- if (unlikely(io_req_cache_empty(ctx)))
- return __io_alloc_req_refill(ctx);
- return true;
-}
-
extern struct kmem_cache *req_cachep;

-static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
+static inline struct io_kiocb *io_extract_req(struct io_ring_ctx *ctx)
{
struct io_kiocb *req;

@@ -352,6 +345,16 @@ static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
return req;
}

+static inline bool io_alloc_req(struct io_ring_ctx *ctx, struct io_kiocb **req)
+{
+ if (unlikely(io_req_cache_empty(ctx))) {
+ if (!__io_alloc_req_refill(ctx))
+ return false;
+ }
+ *req = io_extract_req(ctx);
+ return true;
+}
+
static inline bool io_allowed_defer_tw_run(struct io_ring_ctx *ctx)
{
return likely(ctx->submitter_task == current);
diff --git a/io_uring/notif.c b/io_uring/notif.c
index c4bb793ebf0e..09dfd0832d19 100644
--- a/io_uring/notif.c
+++ b/io_uring/notif.c
@@ -68,9 +68,8 @@ struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx)
struct io_kiocb *notif;
struct io_notif_data *nd;

- if (unlikely(!io_alloc_req_refill(ctx)))
+ if (unlikely(!io_alloc_req(ctx, &notif)))
return NULL;
- notif = io_alloc_req(ctx);
notif->opcode = IORING_OP_NOP;
notif->flags = 0;
notif->file = NULL;
--
2.38.1