[PATCH 2/3] io-wq: split hashing and enqueueing

Pavel Begunkov
2020-03-13T21:32:26Z

It's a preparation patch removing io_wq_enqueue_hashed(), which
now should be done by io_wq_hash_work() + io_wq_enqueue().

Also, set hash value for dependant works, and do it as late as possible,
because req->file can be unavailable before. This hash will be ignored
by io-wq.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
fs/io-wq.c | 14 +++++---------
fs/io-wq.h | 7 ++++++-
fs/io_uring.c | 24 ++++++++++--------------
3 files changed, 21 insertions(+), 24 deletions(-)

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 8afe5565f57a..e26ceef53cbd 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -385,7 +385,7 @@ static struct io_wq_work *io_get_next_work(struct io_wqe *wqe, unsigned *hash)
work = container_of(node, struct io_wq_work, list);

/* not hashed, can run anytime */
- if (!(work->flags & IO_WQ_WORK_HASHED)) {
+ if (!io_wq_is_hashed(work)) {
wq_node_del(&wqe->work_list, node, prev);
return work;
}
@@ -795,19 +795,15 @@ void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
}

/*
- * Enqueue work, hashed by some key. Work items that hash to the same value
- * will not be done in parallel. Used to limit concurrent writes, generally
- * hashed by inode.
+ * Work items that hash to the same value will not be done in parallel.
+ * Used to limit concurrent writes, generally hashed by inode.
*/
-void io_wq_enqueue_hashed(struct io_wq *wq, struct io_wq_work *work, void *val)
+void io_wq_hash_work(struct io_wq_work *work, void *val)
{
- struct io_wqe *wqe = wq->wqes[numa_node_id()];
- unsigned bit;
-
+ unsigned int bit;

bit = hash_ptr(val, IO_WQ_HASH_ORDER);
work->flags |= (IO_WQ_WORK_HASHED | (bit << IO_WQ_HASH_SHIFT));
- io_wqe_enqueue(wqe, work);
}

static bool io_wqe_worker_send_sig(struct io_worker *worker, void *data)
diff --git a/fs/io-wq.h b/fs/io-wq.h
index 2117b9a4f161..298b21f4a4d2 100644
--- a/fs/io-wq.h
+++ b/fs/io-wq.h
@@ -94,7 +94,12 @@ bool io_wq_get(struct io_wq *wq, struct io_wq_data *data);
void io_wq_destroy(struct io_wq *wq);

void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
-void io_wq_enqueue_hashed(struct io_wq *wq, struct io_wq_work *work, void *val);
+void io_wq_hash_work(struct io_wq_work *work, void *val);
+
+static inline bool io_wq_is_hashed(struct io_wq_work *work)
+{
+ return work->flags & IO_WQ_WORK_HASHED;
+}

void io_wq_cancel_all(struct io_wq *wq);
enum io_wq_cancel io_wq_cancel_work(struct io_wq *wq, struct io_wq_work *cwork);
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 9d43efbec960..f1b42690456a 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1040,15 +1040,14 @@ static inline void io_req_work_drop_env(struct io_kiocb *req)
}
}

-static inline bool io_prep_async_work(struct io_kiocb *req,
+static inline void io_prep_async_work(struct io_kiocb *req,
struct io_kiocb **link)
{
const struct io_op_def *def = &io_op_defs[req->opcode];
- bool do_hashed = false;

if (req->flags & REQ_F_ISREG) {
if (def->hash_reg_file)
- do_hashed = true;
+ io_wq_hash_work(&req->work, file_inode(req->file));
} else {
if (def->unbound_nonreg_file)
req->work.flags |= IO_WQ_WORK_UNBOUND;
@@ -1057,25 +1056,18 @@ static inline bool io_prep_async_work(struct io_kiocb *req,
io_req_work_grab_env(req, def);

*link = io_prep_linked_timeout(req);
- return do_hashed;
}

static inline void io_queue_async_work(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_kiocb *link;
- bool do_hashed;

- do_hashed = io_prep_async_work(req, &link);
+ io_prep_async_work(req, &link);

- trace_io_uring_queue_async_work(ctx, do_hashed, req, &req->work,
- req->flags);
- if (!do_hashed) {
- io_wq_enqueue(ctx->io_wq, &req->work);
- } else {
- io_wq_enqueue_hashed(ctx->io_wq, &req->work,
- file_inode(req->file));
- }
+ trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
+ &req->work, req->flags);
+ io_wq_enqueue(ctx->io_wq, &req->work);

if (link)
io_queue_linked_timeout(link);
@@ -1582,6 +1574,10 @@ static void io_link_work_cb(struct io_wq_work **workptr)
static void io_wq_assign_next(struct io_wq_work **workptr, struct io_kiocb *nxt)
{
struct io_kiocb *link;
+ const struct io_op_def *def = &io_op_defs[nxt->opcode];
+
+ if ((nxt->flags & REQ_F_ISREG) && def->hash_reg_file)
+ io_wq_hash_work(&nxt->work, file_inode(nxt->file));

*workptr = &nxt->work;
link = io_prep_linked_timeout(nxt);
--
2.24.0