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 64acf9e..3eda0a6 100644 (file)
--- 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 f50f9ab..85e675d 100644 (file)
--- 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);