net/ice: enlarge Rx queue rearm threshold to 64

[ upstream commit 295906f ]

We observe performance drop on ice AVX512 data path after stop and
start by using testpmd.

As CPU polling is faster in AVX512 path, L3 contested accesses is
intensified when rxrearm_start is a random value after testpmd
stop/start.

Enlarge ICE_RXQ_REARM_THRESH to 64 to ease the contested accesses and
fix the performance drop issue.

Signed-off-by: Leyi Rong <leyi.rong@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>

drivers/net/ice/ice_rxtx.h

@@ -31,7 +31,7 @@
 
 #define ICE_VPMD_RX_BURST           32
 #define ICE_VPMD_TX_BURST           32
-#define ICE_RXQ_REARM_THRESH        32
+#define ICE_RXQ_REARM_THRESH        64
 #define ICE_MAX_RX_BURST            ICE_RXQ_REARM_THRESH
 #define ICE_TX_MAX_FREE_BUF_SZ      64
 #define ICE_DESCS_PER_LOOP          4