Hi, I am writing an application in kernel which needs to make decisions based on RTT of the socket open with another host. So, I was looking at TCP code to find out how can I get that information from it. Whatever little I have understood from the code, it looks like tcp_sock->srtt (smoothed round trip time) is the one I can more or less trust to be the current rtt of the socket and that this value is in jiffies. However I got confused due to the comment on its declaration. u32 srtt; /* smoothed round trip time << 3 */ Questions I have 1) Does this mean that the value stored in this variable is already left shifted by 3 or it should be left shifted by 3 before using it ? Or the value is simply the computed rtt in jiffies and it has no relation with the left shift operation ? 2) Is the SRTT correct value to look at for rtt or should another metric / value be used for this? Regards, Vikash Kumar http://VikashKumar.com/