i've found ktrace of libevent to be a little noisy and hard to read because it
always passes in a changes pointer to kevent, even with a count of 0. this is
just a tiny change to pass NULL in that case, so that kdump doesn't spit out
big hex numbers at me.
Index: kqueue.c
===================================================================
RCS file: /cvs/src/lib/libevent/kqueue.c,v
retrieving revision 1.39
diff -u -p -r1.39 kqueue.c
--- kqueue.c 3 Sep 2016 11:31:17 -0000 1.39
+++ kqueue.c 10 Jul 2017 01:25:57 -0000
@@ -190,7 +190,7 @@ kq_dispatch(struct event_base *base, voi
ts_p = &ts;
}
- res = kevent(kqop->kq, changes, kqop->nchanges,
+ res = kevent(kqop->kq, kqop->nchanges ? changes : NULL, kqop->nchanges,
events, kqop->nevents, ts_p);
kqop->nchanges = 0;
if (res == -1) {
