From: mpi <mpi@openbsd.org>
Date: Thu, 21 Jan 2021 13:19:25 +0000 (+0000)
Subject: Make it possible to convert map arguments to long and insert nsecs in maps.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=03b76035ea8a602fd1ac9eed3049c9dd6a28fe71;p=openbsd

Make it possible to convert map arguments to long and insert nsecs in maps.

Necessary to measure latency, example below to better understand the kqueue
select(2) regression:

syscall:select:entry { @start[pid] = nsecs; }
syscall:select:return { @usecs = hist((nsecs - @start[pid]) / 1000); }
---

diff --git a/usr.sbin/btrace/btrace.c b/usr.sbin/btrace/btrace.c
index 64acf9eaef6..3eda0a638fd 100644
--- a/usr.sbin/btrace/btrace.c
+++ b/usr.sbin/btrace/btrace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: btrace.c,v 1.26 2020/12/07 18:28:09 bluhm Exp $ */
+/*	$OpenBSD: btrace.c,v 1.27 2021/01/21 13:19:25 mpi Exp $ */
 
 /*
  * Copyright (c) 2019 - 2020 Martin Pieuchot <mpi@openbsd.org>
@@ -1030,6 +1030,7 @@ baexpr2long(struct bt_arg *ba, struct dt_evt *dtev)
 long
 ba2long(struct bt_arg *ba, struct dt_evt *dtev)
 {
+	struct bt_var *bv;
 	long val;
 
 	switch (ba->ba_type) {
@@ -1040,6 +1041,11 @@ ba2long(struct bt_arg *ba, struct dt_evt *dtev)
 		ba = ba_read(ba);
 		val = (long)ba->ba_value;
 		break;
+	case B_AT_MAP:
+		bv = ba->ba_value;
+		val = ba2long(map_get((struct map *)bv->bv_value,
+		    ba2str(ba->ba_key, dtev)), dtev);
+		break;
 	case B_AT_BI_NSECS:
 		val = builtin_nsecs(dtev);
 		break;
diff --git a/usr.sbin/btrace/map.c b/usr.sbin/btrace/map.c
index f50f9abdca7..85e675d94f4 100644
--- a/usr.sbin/btrace/map.c
+++ b/usr.sbin/btrace/map.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: map.c,v 1.11 2020/09/18 19:19:38 jasper Exp $ */
+/*	$OpenBSD: map.c,v 1.12 2021/01/21 13:19:25 mpi Exp $ */
 
 /*
  * Copyright (c) 2020 Martin Pieuchot <mpi@openbsd.org>
@@ -138,6 +138,7 @@ map_insert(struct map *map, const char *key, struct bt_arg *bval,
 		free(mep->mval);
 		mep->mval = bval;
 		break;
+	case B_AT_BI_NSECS:
 	case B_AT_BI_RETVAL:
 		free(mep->mval);
 		mep->mval = ba_new(ba2long(bval, dtev), B_AT_LONG);