RE: [PATCH v3] NTB: allocate number transport entries depending on size of ring size

["Allen Hubbe" <Allen.Hubbe@emc.com>]

> From: Dave Jiang
> 
> Currently we only allocate a fixed default number of descriptors for the tx
> and rx side. We should dynamically resize it to the number of descriptors
> resides in the transport rings. We should know the number of transmit
> descriptors at initializaiton. We will allocate the default number of
> descriptors for receive side and allocate additional ones when we know the
> actual max entries for receive.
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Acked-by: Allen Hubbe <allen.hubbe@emc.com>

> ---
>  drivers/ntb/ntb_transport.c |   29 +++++++++++++++++++++++++++--
>  1 file changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> index 2ef9d913..6db8c85 100644
> --- a/drivers/ntb/ntb_transport.c
> +++ b/drivers/ntb/ntb_transport.c
> @@ -153,6 +153,7 @@ struct ntb_transport_qp {
>  	unsigned int rx_index;
>  	unsigned int rx_max_entry;
>  	unsigned int rx_max_frame;
> +	unsigned int rx_alloc_entry;
>  	dma_cookie_t last_cookie;
>  	struct tasklet_struct rxc_db_work;
> 
> @@ -480,7 +481,9 @@ static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
> size_t count,
>  	out_offset += snprintf(buf + out_offset, out_count - out_offset,
>  			       "rx_index - \t%u\n", qp->rx_index);
>  	out_offset += snprintf(buf + out_offset, out_count - out_offset,
> -			       "rx_max_entry - \t%u\n\n", qp->rx_max_entry);
> +			       "rx_max_entry - \t%u\n", qp->rx_max_entry);
> +	out_offset += snprintf(buf + out_offset, out_count - out_offset,
> +			       "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
> 
>  	out_offset += snprintf(buf + out_offset, out_count - out_offset,
>  			       "tx_bytes - \t%llu\n", qp->tx_bytes);
> @@ -597,9 +600,12 @@ static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
>  {
>  	struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
>  	struct ntb_transport_mw *mw;
> +	struct ntb_dev *ndev = nt->ndev;
> +	struct ntb_queue_entry *entry;
>  	unsigned int rx_size, num_qps_mw;
>  	unsigned int mw_num, mw_count, qp_count;
>  	unsigned int i;
> +	int node;
> 
>  	mw_count = nt->mw_count;
>  	qp_count = nt->qp_count;
> @@ -626,6 +632,23 @@ static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
>  	qp->rx_max_entry = rx_size / qp->rx_max_frame;
>  	qp->rx_index = 0;
> 
> +	/*
> +	 * Checking to see if we have more entries than the default.
> +	 * We should add additional entries if that is the case so we
> +	 * can be in sync with the transport frames.
> +	 */
> +	node = dev_to_node(&ndev->dev);
> +	for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
> +		entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
> +		if (!entry)
> +			return -ENOMEM;
> +
> +		entry->qp = qp;
> +		ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
> +			     &qp->rx_free_q);
> +		qp->rx_alloc_entry++;
> +	}
> +
>  	qp->remote_rx_info->entry = qp->rx_max_entry - 1;
> 
>  	/* setup the hdr offsets with 0's */
> @@ -1722,8 +1745,9 @@ ntb_transport_create_queue(void *data, struct device *client_dev,
>  		ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
>  			     &qp->rx_free_q);
>  	}
> +	qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
> 
> -	for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
> +	for (i = 0; i < qp->tx_max_entry; i++) {
>  		entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, node);
>  		if (!entry)
>  			goto err2;
> @@ -1744,6 +1768,7 @@ err2:
>  	while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
>  		kfree(entry);
>  err1:
> +	qp->rx_alloc_entry = 0;
>  	while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
>  		kfree(entry);
>  	if (qp->tx_dma_chan)