From: Gerrit Renker Date: Wed, 21 Mar 2007 18:44:38 +0000 Subject: [PATCH 7/25]: Use skb timestamp for receiver side Message-Id: <200703211844.38743@strip-the-willow> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: dccp@vger.kernel.org [CCID 3]: Use skb timestamp for receiver side This patch replaces calls to do_gettimeofday at the receiver CCID 3 with skb timestamps. The skb timestamps are computed earlier in the receive path, experimental measurements have shown that up to several hundred microseconds can lie between the skb receive timestamp and the timestamp taken when CCID 3 receives the packet. This difference has a negative impact on RTT estimation (reduced accuracy). Signed-off-by: Gerrit Renker --- net/dccp/ccids/lib/packet_history.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/dccp/ccids/lib/packet_history.h +++ b/net/dccp/ccids/lib/packet_history.h @@ -151,7 +151,7 @@ static inline struct dccp_rx_hist_entry entry->dccphrx_ccval = dh->dccph_ccval; entry->dccphrx_type = dh->dccph_type; entry->dccphrx_ndp = ndp; - do_gettimeofday(&entry->dccphrx_tstamp); + skb_get_timestamp(skb, &entry->dccphrx_tstamp); } return entry;