i40e/i40evf: change dynamic interrupt thresholds
The dynamic algorithm, while now working, doesn't have good
performance in 40G mode.
One part of this patch addresses the high CPU utilization of some small
streaming workloads that the driver should reduce CPU in.
It also changes the minimum ITR that the dynamic algorithm
will settle on, causing our minimum latency to go from 12us
to about 14us, when using adaptive mode.
It also changes the BULK interrupt rate to allow maximum throughput
on a 40Gb connection with a single thread of transmit, clamping
interrupt rate to 8000 for TX makes single thread traffic go too
slow.
The new ULTRA bulk setting is introduced and is used
when the Rx packet rate on this queue exceeds 40000 packets per
second. This value of 40000 was chosen because the automatic tuning
of minimum ITR=20us means that a single queue can't quite achieve
that many packets per second from a round-robin test.
Change-ID: Icce8faa128688ca5fd2c4229bdd9726877a92ea2
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
index 03275eb..e2352b8 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
@@ -32,7 +32,9 @@
#define I40E_MAX_ITR 0x0FF0 /* reg uses 2 usec resolution */
#define I40E_MIN_ITR 0x0001 /* reg uses 2 usec resolution */
#define I40E_ITR_100K 0x0005
+#define I40E_ITR_50K 0x000A
#define I40E_ITR_20K 0x0019
+#define I40E_ITR_18K 0x001B
#define I40E_ITR_8K 0x003E
#define I40E_ITR_4K 0x007A
#define I40E_MAX_INTRL 0x3B /* reg uses 4 usec resolution */
@@ -291,6 +293,7 @@
I40E_LOWEST_LATENCY = 0,
I40E_LOW_LATENCY = 1,
I40E_BULK_LATENCY = 2,
+ I40E_ULTRA_LATENCY = 3,
};
struct i40e_ring_container {