X300: Change Ethernet buffering

Ethernet buffering is now done so that most of the buffering is done in
the socket buffers and multiple frames are only used to support the
receive side offload of the socket I/O.  Eliminates dropped packets at
high full duplex rates.

1 files changed, 16 insertions, 15 deletions

diff --git a/host/lib/usrp/x300/x300_impl.hpp b/host/lib/usrp/x300/x300_impl.hpp
index e67242aa3..dfe038107 100644
--- a/host/lib/usrp/x300/x300_impl.hpp
+++ b/host/lib/usrp/x300/x300_impl.hpp
@@ -39,9 +39,6 @@ static const std::string X300_DEFAULT_CLOCK_SOURCE  = "internal";
 static const double X300_DEFAULT_TICK_RATE          = 200e6;   //Hz
 static const double X300_BUS_CLOCK_RATE             = 187.5e6; //Hz
 
-static const size_t X300_RX_SW_BUFF_SIZE_ETH        = 0x2000000;//32MiB    For an ~8k frame size any size >32MiB is just wasted buffer space
-static const size_t X300_RX_SW_BUFF_SIZE_ETH_MACOS  = 0x100000; //1Mib
-
 //The FIFO closest to the DMA controller is 1023 elements deep for RX and 1029 elements deep for TX
 //where an element is 8 bytes. The buffers (number of frames * frame size) must be aligned to the
 //memory page size.  For the control, we are getting lucky because 64 frames * 256 bytes each aligns
@@ -50,22 +47,25 @@ static const size_t X300_RX_SW_BUFF_SIZE_ETH_MACOS  = 0x100000; //1Mib
 static const size_t X300_PCIE_RX_DATA_FRAME_SIZE        = 4096;     //bytes
 static const size_t X300_PCIE_RX_DATA_NUM_FRAMES        = 4096;
 static const size_t X300_PCIE_TX_DATA_FRAME_SIZE        = 4096;     //bytes
-static const size_t X300_PCIE_TX_DATA_NUM_FRAMES	    = 4096;
+static const size_t X300_PCIE_TX_DATA_NUM_FRAMES	= 4096;
 static const size_t X300_PCIE_MSG_FRAME_SIZE            = 256;      //bytes
 static const size_t X300_PCIE_MSG_NUM_FRAMES            = 64;
 static const size_t X300_PCIE_MAX_CHANNELS              = 6;
 static const size_t X300_PCIE_MAX_MUXED_CTRL_XPORTS     = 32;
 static const size_t X300_PCIE_MAX_MUXED_ASYNC_XPORTS    = 4;
 
-//Reduced to 4000 to make sure flow control packets are not blocked for too long at high rates
-static const size_t X300_10GE_DATA_FRAME_MAX_SIZE   = 4000;     // CHDR packet size in bytes
-static const size_t X300_1GE_DATA_FRAME_MAX_SIZE    = 1472;     // CHDR packet size in bytes
+static const size_t X300_DATA_FRAME_MAX_SIZE        = 8000;     // CHDR packet size in bytes
+
+// Ethernet frame sizes
+static const size_t X300_10GE_DATA_FRAME_SEND_SIZE  = 4000;     // Reduced to make sure flow control packets are not blocked for too long at high rates
+static const size_t X300_10GE_DATA_FRAME_RECV_SIZE  = 8000;
+static const size_t X300_1GE_DATA_FRAME_SEND_SIZE   = 1472;
+static const size_t X300_1GE_DATA_FRAME_RECV_SIZE   = 1472;
 static const size_t X300_ETH_MSG_FRAME_SIZE         = uhd::transport::udp_simple::mtu;  //bytes
+static const size_t X300_ETH_MSG_NUM_FRAMES         = 64;
 
-static const double X300_THREAD_BUFFER_TIMEOUT      = 0.1;   // Time in seconds
+static const double X300_RECV_OFFLOAD_BUFFER_TIMEOUT    = 0.1;  //seconds
 
-static const size_t X300_ETH_MSG_NUM_FRAMES         = 64;
-static const size_t X300_ETH_DATA_NUM_FRAMES        = 32;
 static const double X300_DEFAULT_SYSREF_RATE        = 10e6;
 
 // Limit the number of initialization threads
@@ -74,12 +74,12 @@ static const size_t X300_MAX_INIT_THREADS           = 10;
 static const size_t X300_MAX_RATE_PCIE              = 800000000; // bytes/s
 static const size_t X300_MAX_RATE_10GIGE            = (size_t)(  // bytes/s
         10e9 / 8 *                                               // wire speed multiplied by percentage of packets that is sample data
-        ( float(X300_10GE_DATA_FRAME_MAX_SIZE - uhd::usrp::DEVICE3_TX_MAX_HDR_LEN) /
-          float(X300_10GE_DATA_FRAME_MAX_SIZE + 8 /* UDP header */ + 20 /* Ethernet header length */ )));
+        ( float(X300_DATA_FRAME_MAX_SIZE - uhd::usrp::DEVICE3_TX_MAX_HDR_LEN) /
+          float(X300_DATA_FRAME_MAX_SIZE + 8 /* UDP header */ + 20 /* Ethernet header length */ )));
 static const size_t X300_MAX_RATE_1GIGE            = (size_t)(  // bytes/s
-        10e9 / 8 *                                               // wire speed multiplied by percentage of packets that is sample data
-        ( float(X300_1GE_DATA_FRAME_MAX_SIZE - uhd::usrp::DEVICE3_TX_MAX_HDR_LEN) /
-          float(X300_1GE_DATA_FRAME_MAX_SIZE + 8 /* UDP header */ + 20 /* Ethernet header length */ )));
+        1e9 / 8 *                                               // wire speed multiplied by percentage of packets that is sample data
+        ( float(X300_DATA_FRAME_MAX_SIZE - uhd::usrp::DEVICE3_TX_MAX_HDR_LEN) /
+          float(X300_DATA_FRAME_MAX_SIZE + 8 /* UDP header */ + 20 /* Ethernet header length */ )));
 
 #define X300_RADIO_DEST_PREFIX_TX 0
 
@@ -106,6 +106,7 @@ struct x300_eth_conn_t
 {
     std::string addr;
     x300_eth_iface_t type;
+    size_t link_rate;
 };