Commit 4ebb8795 authored by Long Li's avatar Long Li Committed by Steve French
Browse files

cifs: smbd: Check and extend sender credits in interrupt context 



When a RDMA packet is received and server is extending send credits, we should
check and unblock senders immediately in IRQ context. Doing it in a worker
queue causes unnecessary delay and doesn't save much CPU on the receive path.

Signed-off-by: default avatarLong Li <longli@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent f7950cb0

fs/cifs/smbdirect.c

+15 −23
Original line number Diff line number Diff line
@@ -459,25 +459,6 @@ static void smbd_post_send_credits(struct work_struct *work) 
	check_and_send_immediate(info);

}



static void smbd_recv_done_work(struct work_struct *work)

{

	struct smbd_connection *info =

		container_of(work, struct smbd_connection, recv_done_work);



	/*

	 * We may have new send credits granted from remote peer

	 * If any sender is blcoked on lack of credets, unblock it

	 */

	if (atomic_read(&info->send_credits))

		wake_up_interruptible(&info->wait_send_queue);



	/*

	 * Check if we need to send something to remote peer to

	 * grant more credits or respond to KEEP_ALIVE packet

	 */

	check_and_send_immediate(info);

}



/* Called from softirq, when recv is done */

static void recv_done(struct ib_cq *cq, struct ib_wc *wc)

{
@@ -546,8 +527,15 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc) 
		atomic_dec(&info->receive_credits);

		info->receive_credit_target =

			le16_to_cpu(data_transfer->credits_requested);

		if (le16_to_cpu(data_transfer->credits_granted)) {

			atomic_add(le16_to_cpu(data_transfer->credits_granted),

				&info->send_credits);

			/*

			 * We have new send credits granted from remote peer

			 * If any sender is waiting for credits, unblock it

			 */

			wake_up_interruptible(&info->wait_send_queue);

		}



		log_incoming(INFO, "data flags %d data_offset %d "

			"data_length %d remaining_data_length %d\n",
@@ -563,7 +551,12 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc) 
			info->keep_alive_requested = KEEP_ALIVE_PENDING;

		}



		queue_work(info->workqueue, &info->recv_done_work);

		/*

		 * Check if we need to send something to remote peer to

		 * grant more credits or respond to KEEP_ALIVE packet

		 */

		check_and_send_immediate(info);



		return;



	default:
@@ -1762,7 +1755,6 @@ static struct smbd_connection *_smbd_get_connection( 
	atomic_set(&info->send_payload_pending, 0);



	INIT_WORK(&info->disconnect_work, smbd_disconnect_rdma_work);

	INIT_WORK(&info->recv_done_work, smbd_recv_done_work);

	INIT_WORK(&info->post_send_credits_work, smbd_post_send_credits);

	info->new_credits_offered = 0;

	spin_lock_init(&info->lock_new_credits_offered);

fs/cifs/smbdirect.h

+0 −1
Original line number Diff line number Diff line
@@ -67,7 +67,6 @@ struct smbd_connection { 
	bool negotiate_done;



	struct work_struct disconnect_work;

	struct work_struct recv_done_work;

	struct work_struct post_send_credits_work;



	spinlock_t lock_new_credits_offered;

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