On 04/16/2018 08:33 AM, Yafang Shao wrote: > tcp_rcv_space_adjust is called every time data is copied to user space, > introducing a tcp tracepoint for which could show us when the packet is > copied to user. > This could help us figure out whether there's latency in user process. > > When a tcp packet arrives, tcp_rcv_established() will be called and with > the existed tracepoint tcp_probe we could get the time when this packet > arrives. > Then this packet will be copied to user, and tcp_rcv_space_adjust will > be called and with this new introduced tracepoint we could get the time > when this packet is copied to user. > > arrives time : user process time => latency caused by user > tcp_probe tcp_rcv_space_adjust > > Hence in the prink message, sk is printed as a key to connect these two > tracepoints. >
socket pointer is not a key. TCP sockets can be reused pretty fast after free. I suggest you go for cookie instead, this is an unique 64bit identifier. ( sock_gen_cookie() for details )
