Re: [v2 PATCH -tip 3/6] net: sctp: Add SCTP ACK tracking trace event
flat view
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2017-12-18 17:05:28
Also in:
linux-sctp, lkml
On Mon, 18 Dec 2017 17:12:15 +0900 Masami Hiramatsu [off-list ref] wrote:
Add SCTP ACK tracking trace event to trace the changes of SCTP association state in response to incoming packets. It is used for debugging SCTP congestion control algorithms, and will replace sctp_probe module. Note that this event a bit tricky. Since this consists of 2 events (sctp_probe and sctp_probe_path) so you have to enable both events as below. # cd /sys/kernel/debug/tracing # echo 1 > events/sctp/sctp_probe/enable # echo 1 > events/sctp/sctp_probe_path/enable Or, you can enable all the events under sctp. # echo 1 > events/sctp/enable Since sctp_probe_path event is always invoked from sctp_probe event, you can not see any output if you only enable sctp_probe_path.
I have to ask, why did you do it this way?
quoted hunk ↗ jump to hunk
+#include <trace/define_trace.h>diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 8f8ccded13e4..c5f92b2cc5c3 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c@@ -59,6 +59,9 @@ #include <net/sctp/sm.h> #include <net/sctp/structs.h> +#define CREATE_TRACE_POINTS +#include <trace/events/sctp.h> + static struct sctp_packet *sctp_abort_pkt_new( struct net *net, const struct sctp_endpoint *ep,@@ -3219,6 +3222,8 @@ enum sctp_disposition sctp_sf_eat_sack_6_2(struct net *net, struct sctp_sackhdr *sackh; __u32 ctsn; + trace_sctp_probe(ep, asoc, chunk);
What about doing this right after this probe:
if (trace_sctp_probe_path_enabled()) {
struct sctp_transport *sp;
list_for_each_entry(sp, &asoc->peer.transpor_addr_list,
transports) {
trace_sctp_probe_path(sp, asoc);
}
}
The "trace_sctp_probe_path_enabled()" is a static branch, which means
it's a nop just like a tracepoint is, and will not add any overhead if
the trace_sctp_probe_path is not enabled.
-- Steve
quoted hunk ↗ jump to hunk
+ if (!sctp_vtag_verify(chunk, asoc)) return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);