Re: [Patch net-next v2] tcp: add a tracepoint for tcp_retransmit_skb()

2017-10-13 Thread Cong Wang
On Thu, Oct 12, 2017 at 4:18 PM, Alexei Starovoitov wrote: > On Thu, Oct 12, 2017 at 03:48:07PM -0700, Cong Wang wrote: >> We need a real-time notification for tcp retransmission >> for monitoring. >> >> Of course we could use ftrace to dynamically instrument this >> kernel function too, however w

Re: [Patch net-next v2] tcp: add a tracepoint for tcp_retransmit_skb()

2017-10-12 Thread Alexei Starovoitov
On Thu, Oct 12, 2017 at 03:48:07PM -0700, Cong Wang wrote: > We need a real-time notification for tcp retransmission > for monitoring. > > Of course we could use ftrace to dynamically instrument this > kernel function too, however we can't retrieve the connection > information at the same time, fo

[Patch net-next v2] tcp: add a tracepoint for tcp_retransmit_skb()

2017-10-12 Thread Cong Wang
We need a real-time notification for tcp retransmission for monitoring. Of course we could use ftrace to dynamically instrument this kernel function too, however we can't retrieve the connection information at the same time, for example perf-tools [1] reads /proc/net/tcp for socket details, which