fuse: optimize over-io-uring request expiration check

Currently, when checking whether a request has timed out, we check
fpq processing, but fuse-over-io-uring has one fpq per core and 256
entries in the processing table. For systems where there are a
large number of cores, this may be too much overhead.

Instead of checking the fpq processing list, check ent_w_req_queue
and ent_in_userspace.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Bernd Schubert <bernd@bsbernd.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Author: joannekoong

fs/fuse/dev.c

@@ -45,7 +45,7 @@ bool fuse_request_expired(struct fuse_conn *fc, struct list_head *list)
 	return time_is_before_jiffies(req->create_time + fc->timeout.req_timeout);
 }
 
-bool fuse_fpq_processing_expired(struct fuse_conn *fc, struct list_head *processing)
+static bool fuse_fpq_processing_expired(struct fuse_conn *fc, struct list_head *processing)
 {
 	int i;
 

fs/fuse/dev_uring.c

@@ -140,6 +140,21 @@ void fuse_uring_abort_end_requests(struct fuse_ring *ring)
 	}
 }
 
+static bool ent_list_request_expired(struct fuse_conn *fc, struct list_head *list)
+{
+	struct fuse_ring_ent *ent;
+	struct fuse_req *req;
+
+	ent = list_first_entry_or_null(list, struct fuse_ring_ent, list);
+	if (!ent)
+		return false;
+
+	req = ent->fuse_req;
+
+	return time_is_before_jiffies(req->create_time +
+				      fc->timeout.req_timeout);
+}
+
 bool fuse_uring_request_expired(struct fuse_conn *fc)
 {
 	struct fuse_ring *ring = fc->ring;
@@ -157,7 +172,8 @@ bool fuse_uring_request_expired(struct fuse_conn *fc)
 		spin_lock(&queue->lock);
 		if (fuse_request_expired(fc, &queue->fuse_req_queue) ||
 		    fuse_request_expired(fc, &queue->fuse_req_bg_queue) ||
-		    fuse_fpq_processing_expired(fc, queue->fpq.processing)) {
+		    ent_list_request_expired(fc, &queue->ent_w_req_queue) ||
+		    ent_list_request_expired(fc, &queue->ent_in_userspace)) {
 			spin_unlock(&queue->lock);
 			return true;
 		}
@@ -494,7 +510,7 @@ static void fuse_uring_cancel(struct io_uring_cmd *cmd,
 	spin_lock(&queue->lock);
 	if (ent->state == FRRS_AVAILABLE) {
 		ent->state = FRRS_USERSPACE;
-		list_move(&ent->list, &queue->ent_in_userspace);
+		list_move_tail(&ent->list, &queue->ent_in_userspace);
 		need_cmd_done = true;
 		ent->cmd = NULL;
 	}
@@ -714,7 +730,7 @@ static int fuse_uring_send_next_to_ring(struct fuse_ring_ent *ent,
 	cmd = ent->cmd;
 	ent->cmd = NULL;
 	ent->state = FRRS_USERSPACE;
-	list_move(&ent->list, &queue->ent_in_userspace);
+	list_move_tail(&ent->list, &queue->ent_in_userspace);
 	spin_unlock(&queue->lock);
 
 	io_uring_cmd_done(cmd, 0, 0, issue_flags);
@@ -764,7 +780,7 @@ static void fuse_uring_add_req_to_ring_ent(struct fuse_ring_ent *ent,
 	clear_bit(FR_PENDING, &req->flags);
 	ent->fuse_req = req;
 	ent->state = FRRS_FUSE_REQ;
-	list_move(&ent->list, &queue->ent_w_req_queue);
+	list_move_tail(&ent->list, &queue->ent_w_req_queue);
 	fuse_uring_add_to_pq(ent, req);
 }
 
@@ -1180,7 +1196,7 @@ static void fuse_uring_send(struct fuse_ring_ent *ent, struct io_uring_cmd *cmd,
 
 	spin_lock(&queue->lock);
 	ent->state = FRRS_USERSPACE;
-	list_move(&ent->list, &queue->ent_in_userspace);
+	list_move_tail(&ent->list, &queue->ent_in_userspace);
 	ent->cmd = NULL;
 	spin_unlock(&queue->lock);
 

fs/fuse/fuse_dev_i.h

@@ -64,7 +64,6 @@ void fuse_dev_queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req);
 bool fuse_remove_pending_req(struct fuse_req *req, spinlock_t *lock);
 
 bool fuse_request_expired(struct fuse_conn *fc, struct list_head *list);
-bool fuse_fpq_processing_expired(struct fuse_conn *fc, struct list_head *processing);
 
 #endif