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Commit 2b65326e authored by Jesse Brandeburg's avatar Jesse Brandeburg Committed by Jeff Garzik
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[PATCH] e1000: dynamic itr: take TSO and jumbo into account 



The dynamic interrupt rate control patches omitted proper counting
for jumbo's and TSO resulting in suboptimal interrupt mitigation strategies.

Signed-off-by: default avatarJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: default avatarAuke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 7d16e65b

drivers/net/e1000/e1000_main.c

+24 −16
Original line number Diff line number Diff line
@@ -2628,28 +2628,33 @@ static unsigned int e1000_update_itr(struct e1000_adapter *adapter, 
	if (packets == 0)

		goto update_itr_done;





	switch (itr_setting) {

	case lowest_latency:

		if ((packets < 5) && (bytes > 512))

		/* jumbo frames get bulk treatment*/

		if (bytes/packets > 8000)

			retval = bulk_latency;

		else if ((packets < 5) && (bytes > 512))

			retval = low_latency;

		break;

	case low_latency:  /* 50 usec aka 20000 ints/s */

		if (bytes > 10000) {

			if ((packets < 10) ||

			     ((bytes/packets) > 1200))

			/* jumbo frames need bulk latency setting */

			if (bytes/packets > 8000)

				retval = bulk_latency;

			else if ((packets < 10) || ((bytes/packets) > 1200))

				retval = bulk_latency;

			else if ((packets > 35))

				retval = lowest_latency;

		} else if (packets <= 2 && bytes < 512)

		} else if (bytes/packets > 2000)

			retval = bulk_latency;

		else if (packets <= 2 && bytes < 512)

			retval = lowest_latency;

		break;

	case bulk_latency: /* 250 usec aka 4000 ints/s */

		if (bytes > 25000) {

			if (packets > 35)

				retval = low_latency;

		} else {

			if (bytes < 6000)

		} else if (bytes < 6000) {

			retval = low_latency;

		}

		break;
@@ -2679,17 +2684,20 @@ static void e1000_set_itr(struct e1000_adapter *adapter) 
	                            adapter->tx_itr,

	                            adapter->total_tx_packets,

	                            adapter->total_tx_bytes);

	/* conservative mode (itr 3) eliminates the lowest_latency setting */

	if (adapter->itr_setting == 3 && adapter->tx_itr == lowest_latency)

		adapter->tx_itr = low_latency;



	adapter->rx_itr = e1000_update_itr(adapter,

	                            adapter->rx_itr,

	                            adapter->total_rx_packets,

	                            adapter->total_rx_bytes);

	/* conservative mode (itr 3) eliminates the lowest_latency setting */

	if (adapter->itr_setting == 3 && adapter->rx_itr == lowest_latency)

		adapter->rx_itr = low_latency;



	current_itr = max(adapter->rx_itr, adapter->tx_itr);



	/* conservative mode eliminates the lowest_latency setting */

	if (current_itr == lowest_latency && (adapter->itr_setting == 3))

		current_itr = low_latency;



	switch (current_itr) {

	/* counts and packets in update_itr are dependent on these numbers */

	case lowest_latency:
@@ -3868,11 +3876,11 @@ e1000_clean_tx_irq(struct e1000_adapter *adapter, 
			cleaned = (i == eop);



			if (cleaned) {

				/* this packet count is wrong for TSO but has a

				 * tendency to make dynamic ITR change more

				 * towards bulk */

				struct sk_buff *skb = buffer_info->skb;

				unsigned int segs = skb_shinfo(skb)->gso_segs;

				total_tx_packets += segs;

				total_tx_packets++;

				total_tx_bytes += buffer_info->skb->len;

				total_tx_bytes += skb->len;

			}

			e1000_unmap_and_free_tx_resource(adapter, buffer_info);

			tx_desc->upper.data = 0;