Also show the time spent in userland when analyzing the kernel stack

in flame graph.  Only when both kernel and userland are displayed,
the whole picture of system activity becomes clear.  Fixes a parsing
bug in the flame graph tool where userland time was interpreted as
invalid kernel stack.
OK kn@

diff --git a/usr.sbin/btrace/btrace.c b/usr.sbin/btrace/btrace.c
index 961500a..75966f8 100644 (file)
--- a/usr.sbin/btrace/btrace.c
+++ b/usr.sbin/btrace/btrace.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: btrace.c,v 1.37 2021/06/23 11:24:01 dv Exp $ */
+/*     $OpenBSD: btrace.c,v 1.38 2021/06/28 08:55:06 bluhm Exp $ */
 
 /*
  * Copyright (c) 2019 - 2020 Martin Pieuchot <mpi@openbsd.org>
@@ -638,8 +638,10 @@ builtin_stack(struct dt_evt *dtev, int kernel)
        size_t i;
        int sz;
 
-       if (!kernel || st->st_count == 0)
+       if (!kernel)
                return "";
+       if (st->st_count == 0)
+               return "\nuserland\n";
 
        buf[0] = '\0';
        bp = buf;
@@ -658,7 +660,7 @@ builtin_stack(struct dt_evt *dtev, int kernel)
                bp += l;
                sz -= l;
        }
-       snprintf(bp, sz, "\n");
+       snprintf(bp, sz, "\nkernel\n");
 
        return buf;
 }