From f398efc14a9277b55defff71f59a46fdf13c713f Mon Sep 17 00:00:00 2001 From: Kevin Kou Date: Fri, 27 Dec 2019 13:11:16 +0000 Subject: sctp: add enabled check for path tracepoint loop. sctp_outq_sack is the main function handles SACK, it is called very frequently. As the commit "move trace_sctp_probe_path into sctp_outq_sack" added below code to this function, sctp tracepoint is disabled most of time, but the loop of transport list will be always called even though the tracepoint is disabled, this is unnecessary. + /* SCTP path tracepoint for congestion control debugging. */ + list_for_each_entry(transport, transport_list, transports) { + trace_sctp_probe_path(transport, asoc); + } This patch is to add tracepoint enabled check at outside of the loop of transport list, and avoid traversing the loop when trace is disabled, it is a small optimization. Signed-off-by: Kevin Kou Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/outqueue.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index 6b0b3bad4daa..577e3bc4ee6f 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -1240,8 +1240,9 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_chunk *chunk) transport_list = &asoc->peer.transport_addr_list; /* SCTP path tracepoint for congestion control debugging. */ - list_for_each_entry(transport, transport_list, transports) { - trace_sctp_probe_path(transport, asoc); + if (trace_sctp_probe_path_enabled()) { + list_for_each_entry(transport, transport_list, transports) + trace_sctp_probe_path(transport, asoc); } sack_ctsn = ntohl(sack->cum_tsn_ack); -- cgit v1.2.3