On Sun, Dec 31, 2017 at 6:33 AM, Brendan Gregg <[email protected]> wrote: > On Tue, Dec 19, 2017 at 7:12 PM, Yafang Shao <[email protected]> wrote: >> As sk_state is a common field for struct sock, so the state >> transition tracepoint should not be a TCP specific feature. >> Currently it traces all AF_INET state transition, so I rename this >> tracepoint to inet_sock_set_state tracepoint with some minor changes and >> move it >> into trace/events/sock.h. > > The tcp:tcp_set_state probe is tcp_set_state(), so it's only going to > fire for TCP sessions. It's not broken, and we could add a > sctp:sctp_set_state as well. Replacing tcp:tcp_set_state with > inet_sk_set_state is feeling like we might be baking too much > implementation detail into the tracepoint API. > > If we must have inet_sk_set_state, then must we also delete tcp:tcp_set_state? >
Hi Brendan, The reason we have to make this change could be got from this mail thread, https://patchwork.kernel.org/patch/10099243/ . The original tcp:tcp_set_state probe doesn't traced all TCP state transitions. There're some state transitions in inet_connection_sock.c and inet_hashtables.c are missed. So we have to place this probe into these two files to fix the issue. But as inet_connection_sock.c and inet_hashtables.c are common files for all IPv4 protocols, not only for TCP, so it is not proper to place a tcp_ function in these two files. That's why we decide to rename tcp:tcp_set_state probe to sock:inet_sock_set_state. Thanks Yafang
