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-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_txrx.c22
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_txrx.h1
-rw-r--r--drivers/net/ethernet/intel/i40evf/i40e_txrx.c22
-rw-r--r--drivers/net/ethernet/intel/i40evf/i40e_txrx.h1
4 files changed, 36 insertions, 10 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index f00f233092e9..1519dfb851d0 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -961,11 +961,25 @@ static bool i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
enum i40e_latency_range new_latency_range = rc->latency_range;
u32 new_itr = rc->itr;
int bytes_per_int;
- int usecs;
+ unsigned int usecs, estimated_usecs;
if (rc->total_packets == 0 || !rc->itr)
return false;
+ usecs = (rc->itr << 1) * ITR_COUNTDOWN_START;
+ bytes_per_int = rc->total_bytes / usecs;
+
+ /* The calculations in this algorithm depend on interrupts actually
+ * firing at the ITR rate. This may not happen if the packet rate is
+ * really low, or if we've been napi polling. Check to make sure
+ * that's not the case before we continue.
+ */
+ estimated_usecs = jiffies_to_usecs(jiffies - rc->last_itr_update);
+ if (estimated_usecs > usecs) {
+ new_latency_range = I40E_LOW_LATENCY;
+ goto reset_latency;
+ }
+
/* simple throttlerate management
* 0-10MB/s lowest (50000 ints/s)
* 10-20MB/s low (20000 ints/s)
@@ -977,9 +991,6 @@ static bool i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
* are in 2 usec increments in the ITR registers, and make sure
* to use the smoothed values that the countdown timer gives us.
*/
- usecs = (rc->itr << 1) * ITR_COUNTDOWN_START;
- bytes_per_int = rc->total_bytes / usecs;
-
switch (new_latency_range) {
case I40E_LOWEST_LATENCY:
if (bytes_per_int > 10)
@@ -998,6 +1009,7 @@ static bool i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
break;
}
+reset_latency:
rc->latency_range = new_latency_range;
switch (new_latency_range) {
@@ -1016,12 +1028,12 @@ static bool i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
rc->total_bytes = 0;
rc->total_packets = 0;
+ rc->last_itr_update = jiffies;
if (new_itr != rc->itr) {
rc->itr = new_itr;
return true;
}
-
return false;
}
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index e6456e8a899c..2f848bc5e391 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -461,6 +461,7 @@ struct i40e_ring_container {
struct i40e_ring *ring;
unsigned int total_bytes; /* total bytes processed this int */
unsigned int total_packets; /* total packets processed this int */
+ unsigned long last_itr_update; /* jiffies of last ITR update */
u16 count;
enum i40e_latency_range latency_range;
u16 itr;
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index 2f7d9f4a6746..c32c62462c84 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -359,11 +359,25 @@ static bool i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
enum i40e_latency_range new_latency_range = rc->latency_range;
u32 new_itr = rc->itr;
int bytes_per_int;
- int usecs;
+ unsigned int usecs, estimated_usecs;
if (rc->total_packets == 0 || !rc->itr)
return false;
+ usecs = (rc->itr << 1) * ITR_COUNTDOWN_START;
+ bytes_per_int = rc->total_bytes / usecs;
+
+ /* The calculations in this algorithm depend on interrupts actually
+ * firing at the ITR rate. This may not happen if the packet rate is
+ * really low, or if we've been napi polling. Check to make sure
+ * that's not the case before we continue.
+ */
+ estimated_usecs = jiffies_to_usecs(jiffies - rc->last_itr_update);
+ if (estimated_usecs > usecs) {
+ new_latency_range = I40E_LOW_LATENCY;
+ goto reset_latency;
+ }
+
/* simple throttlerate management
* 0-10MB/s lowest (50000 ints/s)
* 10-20MB/s low (20000 ints/s)
@@ -375,9 +389,6 @@ static bool i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
* are in 2 usec increments in the ITR registers, and make sure
* to use the smoothed values that the countdown timer gives us.
*/
- usecs = (rc->itr << 1) * ITR_COUNTDOWN_START;
- bytes_per_int = rc->total_bytes / usecs;
-
switch (new_latency_range) {
case I40E_LOWEST_LATENCY:
if (bytes_per_int > 10)
@@ -396,6 +407,7 @@ static bool i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
break;
}
+reset_latency:
rc->latency_range = new_latency_range;
switch (new_latency_range) {
@@ -414,12 +426,12 @@ static bool i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
rc->total_bytes = 0;
rc->total_packets = 0;
+ rc->last_itr_update = jiffies;
if (new_itr != rc->itr) {
rc->itr = new_itr;
return true;
}
-
return false;
}
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
index fb506c9f5a6e..0d9f98bc07bd 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
@@ -432,6 +432,7 @@ struct i40e_ring_container {
struct i40e_ring *ring;
unsigned int total_bytes; /* total bytes processed this int */
unsigned int total_packets; /* total packets processed this int */
+ unsigned long last_itr_update; /* jiffies of last ITR update */
u16 count;
enum i40e_latency_range latency_range;
u16 itr;