From 6e3057ddddb77835664f5264a7da62452dc3d9c1 Mon Sep 17 00:00:00 2001
From: Lukas Larsson <lukas@erlang-solutions.com>
Date: Thu, 11 Sep 2014 18:26:00 +0200
Subject: erts: Allow cpu_timestamp tracing for Linux
---
erts/aclocal.m4 | 38 ++++++++++++++---------------------
erts/doc/src/erlang.xml | 4 +++-
erts/emulator/beam/erl_bif_trace.c | 4 ++--
erts/emulator/beam/erl_time.h | 2 +-
erts/emulator/sys/unix/erl_unix_sys.h | 4 ++--
5 files changed, 23 insertions(+), 29 deletions(-)
(limited to 'erts')
diff --git a/erts/aclocal.m4 b/erts/aclocal.m4
index d78025b0be..63f5a9c840 100644
--- a/erts/aclocal.m4
+++ b/erts/aclocal.m4
@@ -1881,38 +1881,30 @@ case $erl_gethrvtime in
exit(0); return 0;
}
],
- erl_clock_gettime=yes,
- erl_clock_gettime=no,
+ erl_clock_gettime_cpu_time=yes,
+ erl_clock_gettime_cpu_time=no,
[
case X$erl_xcomp_clock_gettime_cpu_time in
- X) erl_clock_gettime=cross;;
- Xyes|Xno) erl_clock_gettime=$erl_xcomp_clock_gettime_cpu_time;;
+ X) erl_clock_gettime_cpu_time=cross;;
+ Xyes|Xno) erl_clock_gettime_cpu_time=$erl_xcomp_clock_gettime_cpu_time;;
*) AC_MSG_ERROR([Bad erl_xcomp_clock_gettime_cpu_time value: $erl_xcomp_clock_gettime_cpu_time]);;
esac
])
LIBS=$save_libs
- case $host_os in
- linux*)
- AC_MSG_RESULT([no; not stable])
+ AC_MSG_RESULT($erl_clock_gettime_cpu_time)
+ case $erl_clock_gettime_cpu_time in
+ yes)
+ AC_DEFINE(HAVE_CLOCK_GETTIME_CPU_TIME,[],
+ [define if clock_gettime() works for getting process time])
+ LIBRT=-lrt
+ ;;
+ cross)
+ erl_clock_gettime_cpu_time=no
+ AC_MSG_WARN([result no guessed because of cross compilation])
LIBRT=$xrtlib
;;
*)
- AC_MSG_RESULT($erl_clock_gettime)
- case $erl_clock_gettime in
- yes)
- AC_DEFINE(HAVE_CLOCK_GETTIME,[],
- [define if clock_gettime() works for getting process time])
- LIBRT=-lrt
- ;;
- cross)
- erl_clock_gettime=no
- AC_MSG_WARN([result no guessed because of cross compilation])
- LIBRT=$xrtlib
- ;;
- *)
- LIBRT=$xrtlib
- ;;
- esac
+ LIBRT=$xrtlib
;;
esac
AC_SUBST(LIBRT)
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index f9e8717847..37431cbf1b 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -6829,7 +6829,9 @@ ok
only allowed with <c>PidSpec==all</c>. If the host
machine operating system does not support high resolution
CPU time measurements, <c>trace/3</c> exits with
- <c>badarg</c>.</p>
+ <c>badarg</c>. Note that most operating systems do
+ not synchronize this value across cores, so be prepared
+ that time might seem to go backwards when using this option.</p>
</item>
<tag><c>arity</c></tag>
<item>
diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index 06fbbea123..f5e582b1c5 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -651,7 +651,7 @@ Eterm trace_3(BIF_ALIST_3)
if (pid_spec == am_all) {
if (on) {
if (!erts_cpu_timestamp) {
-#ifdef HAVE_CLOCK_GETTIME
+#ifdef HAVE_CLOCK_GETTIME_CPU_TIME
/*
Perhaps clock_gettime was found during config
on a different machine than this. We check
@@ -678,7 +678,7 @@ Eterm trace_3(BIF_ALIST_3)
if (erts_start_now_cpu() < 0) {
goto error;
}
-#endif /* HAVE_CLOCK_GETTIME */
+#endif /* HAVE_CLOCK_GETTIME_CPU_TIME */
erts_cpu_timestamp = !0;
}
}
diff --git a/erts/emulator/beam/erl_time.h b/erts/emulator/beam/erl_time.h
index 4bbdcaa3e3..7ed1a395ad 100644
--- a/erts/emulator/beam/erl_time.h
+++ b/erts/emulator/beam/erl_time.h
@@ -107,7 +107,7 @@ ERTS_GLB_INLINE void erts_do_time_add(erts_short_time_t elapsed)
/* time_sup */
-#if (defined(HAVE_GETHRVTIME) || defined(HAVE_CLOCK_GETTIME))
+#if (defined(HAVE_GETHRVTIME) || defined(HAVE_CLOCK_GETTIME_CPU_TIME))
# ifndef HAVE_ERTS_NOW_CPU
# define HAVE_ERTS_NOW_CPU
# ifdef HAVE_GETHRVTIME
diff --git a/erts/emulator/sys/unix/erl_unix_sys.h b/erts/emulator/sys/unix/erl_unix_sys.h
index 26ed2fb558..b6bca5c0f4 100644
--- a/erts/emulator/sys/unix/erl_unix_sys.h
+++ b/erts/emulator/sys/unix/erl_unix_sys.h
@@ -188,7 +188,7 @@ typedef hrtime_t SysHrTime;
#endif /* GETHRTIME_WITH_CLOCK_GETTIME */
#endif /* HAVE_GETHRTIME */
-#if (defined(HAVE_GETHRVTIME) || defined(HAVE_CLOCK_GETTIME))
+#if (defined(HAVE_GETHRVTIME) || defined(HAVE_CLOCK_GETTIME_CPU_TIME))
typedef long long SysCpuTime;
typedef struct timespec SysTimespec;
@@ -200,7 +200,7 @@ typedef struct timespec SysTimespec;
int sys_start_hrvtime(void);
int sys_stop_hrvtime(void);
-#elif defined(HAVE_CLOCK_GETTIME)
+#elif defined(HAVE_CLOCK_GETTIME_CPU_TIME)
#define sys_clock_gettime(cid,tp) clock_gettime((cid),&(tp))
#define sys_get_proc_cputime(t,tp) sys_clock_gettime(CLOCK_PROCESS_CPUTIME_ID,(tp))
--
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