That's it, honour hashing for dependant works in io-wq.
Pavel Begunkov (3):
io-wq: don't reshed if there is no work
io-wq: split hashing and enqueueing
io-wq: hash dependant works
fs/io-wq.c | 49 ++++++++++++++++++++++++++++++-------------------
fs/io-wq.h | 7 ++++++-
fs/io_uring.c | 24 ++++++++++--------------
3 files changed, 46 insertions(+), 34 deletions(-)
--
2.24.0
This little tweak restores the behaviour that was before the recent
io_worker_handle_work() optimisation patches. It makes the function do
cond_resched() and flush_signals() only if there is an actual work to
execute.
Signed-off-by: Pavel Begunkov <[email protected]>
---
fs/io-wq.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/fs/io-wq.c b/fs/io-wq.c
index 0e7c6277afcb..8afe5565f57a 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -458,10 +458,12 @@ static void io_impersonate_work(struct io_worker *worker,
static void io_assign_current_work(struct io_worker *worker,
struct io_wq_work *work)
{
- /* flush pending signals before assigning new work */
- if (signal_pending(current))
- flush_signals(current);
- cond_resched();
+ if (work) {
+ /* flush pending signals before assigning new work */
+ if (signal_pending(current))
+ flush_signals(current);
+ cond_resched();
+ }
spin_lock_irq(&worker->lock);
worker->cur_work = work;
--
2.24.0
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 <[email protected]>
---
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
Enable io-wq hashing stuff for dependant works simply by re-enqueueing
such requests.
Signed-off-by: Pavel Begunkov <[email protected]>
---
fs/io-wq.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/fs/io-wq.c b/fs/io-wq.c
index e26ceef53cbd..9541df2729de 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -375,11 +375,17 @@ static bool __io_worker_idle(struct io_wqe *wqe, struct io_worker *worker)
return __io_worker_unuse(wqe, worker);
}
-static struct io_wq_work *io_get_next_work(struct io_wqe *wqe, unsigned *hash)
+static inline unsigned int io_get_work_hash(struct io_wq_work *work)
+{
+ return work->flags >> IO_WQ_HASH_SHIFT;
+}
+
+static struct io_wq_work *io_get_next_work(struct io_wqe *wqe)
__must_hold(wqe->lock)
{
struct io_wq_work_node *node, *prev;
struct io_wq_work *work;
+ unsigned int hash;
wq_list_for_each(node, prev, &wqe->work_list) {
work = container_of(node, struct io_wq_work, list);
@@ -391,9 +397,9 @@ static struct io_wq_work *io_get_next_work(struct io_wqe *wqe, unsigned *hash)
}
/* hashed, can run if not already running */
- *hash = work->flags >> IO_WQ_HASH_SHIFT;
- if (!(wqe->hash_map & BIT(*hash))) {
- wqe->hash_map |= BIT(*hash);
+ hash = io_get_work_hash(work);
+ if (!(wqe->hash_map & BIT(hash))) {
+ wqe->hash_map |= BIT(hash);
wq_node_del(&wqe->work_list, node, prev);
return work;
}
@@ -470,15 +476,17 @@ static void io_assign_current_work(struct io_worker *worker,
spin_unlock_irq(&worker->lock);
}
+static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work);
+
static void io_worker_handle_work(struct io_worker *worker)
__releases(wqe->lock)
{
struct io_wqe *wqe = worker->wqe;
struct io_wq *wq = wqe->wq;
- unsigned hash = -1U;
do {
struct io_wq_work *work;
+ unsigned int hash;
get_next:
/*
* If we got some work, mark us as busy. If we didn't, but
@@ -487,7 +495,7 @@ static void io_worker_handle_work(struct io_worker *worker)
* can't make progress, any work completion or insertion will
* clear the stalled flag.
*/
- work = io_get_next_work(wqe, &hash);
+ work = io_get_next_work(wqe);
if (work)
__io_worker_busy(wqe, worker, work);
else if (!wq_list_empty(&wqe->work_list))
@@ -511,11 +519,16 @@ static void io_worker_handle_work(struct io_worker *worker)
work->flags |= IO_WQ_WORK_CANCEL;
old_work = work;
+ hash = io_get_work_hash(work);
work->func(&work);
work = (old_work == work) ? NULL : work;
io_assign_current_work(worker, work);
wq->free_work(old_work);
+ if (work && io_wq_is_hashed(work)) {
+ io_wqe_enqueue(wqe, work);
+ work = NULL;
+ }
if (hash != -1U) {
spin_lock_irq(&wqe->lock);
wqe->hash_map &= ~BIT_ULL(hash);
--
2.24.0
On 3/13/20 3:31 PM, Pavel Begunkov wrote:
> That's it, honour hashing for dependant works in io-wq.
Looks good to me, applied for 5.7, thanks.
--
Jens Axboe