From b25cb48e6e9b4c496d0360a11174f2f174e52df6 Mon Sep 17 00:00:00 2001 From: Josh Blum Date: Mon, 18 Jul 2011 16:16:37 -0700 Subject: udp: check for FastSendDatagramThreshold + print warning inside the wsa transport --- host/lib/transport/udp_wsa_zero_copy.cpp | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'host') diff --git a/host/lib/transport/udp_wsa_zero_copy.cpp b/host/lib/transport/udp_wsa_zero_copy.cpp index ccfed38ea..1acaa7eb1 100644 --- a/host/lib/transport/udp_wsa_zero_copy.cpp +++ b/host/lib/transport/udp_wsa_zero_copy.cpp @@ -32,6 +32,30 @@ namespace asio = boost::asio; //A reasonable number of frames for send/recv and async/sync static const size_t DEFAULT_NUM_FRAMES = 32; +/*********************************************************************** + * Check registry for correct fast-path setting + **********************************************************************/ +#include //CRegKey +static void check_registry_for_fast_send_threshold(const size_t mtu){ + static bool warned = false; + if (warned) return; //only allow one printed warning per process + + CRegKey reg_key; + DWORD threshold = 1024; //system default when threshold is not specified + if ( + reg_key.Open(HKEY_LOCAL_MACHINE, "System\\CurrentControlSet\\Services\\AFD\\Parameters", KEY_READ) != ERROR_SUCCESS or + reg_key.QueryDWORDValue("FastSendDatagramThreshold", threshold) != ERROR_SUCCESS or threshold < mtu + ){ + UHD_MSG(warning) << boost::format( + "The MTU (%d) is larger than the FastSendDatagramThreshold (%d)!\n" + "This will negatively affect the transmit performance.\n" + "See the transport application notes for more detail.\n" + ) % mtu % threshold << std::endl; + warned = true; + } + reg_key.Close(); +} + /*********************************************************************** * Static initialization to take care of WSA init and cleanup **********************************************************************/ @@ -159,6 +183,7 @@ public: _pending_recv_buffs(_num_recv_frames), _next_send_buff_index(0) { + check_registry_for_fast_send_threshold(this->get_send_frame_size()); UHD_MSG(status) << boost::format("Creating WSA UDP transport for %s:%s") % addr % port << std::endl; static uhd_wsa_control uhd_wsa; //makes wsa start happen via lazy initialization -- cgit v1.2.3