initial checkin of tool to analyze libosmocore logging latencyHEADmaster

1 files changed, 246 insertions, 0 deletions

diff --git a/libosmocore-usdt.patch b/libosmocore-usdt.patch
new file mode 100644
index 0000000..97cf3c2
--- /dev/null
+++ b/libosmocore-usdt.patch
@@ -0,0 +1,246 @@
+From d08b4443ea1e5cd64a394832c4af685e06110fcc Mon Sep 17 00:00:00 2001
+From: Harald Welte <laforge@osmocom.org>
+Date: Sat, 26 Sep 2020 11:51:32 +0200
+Subject: [PATCH] initial support for static userspace probes via systemtap
+
+This adds a --enable-systemtap configure option, which will then
+add static tracepoints to the generated libosmocore binary.
+
+At this point, only two tracepoints are supported: stderr_start
+and stderr_done.  They can be used to trace the amount of time
+a libosmocore-using application spends in blocking calls to log
+to stderr.
+
+Change-Id: I7e1ab664241deb524c9582cbd1bec31af46c747e
+---
+ Makefile.am            |  2 +-
+ configure.ac           | 33 +++++++++++++++++++++++++++++++++
+ src/Makefile.am        | 12 ++++++++++++
+ src/logging.c          | 23 ++++++++++++++++++++++-
+ src/probes.d           |  7 +++++++
+ tapset/Makefile.am     | 22 ++++++++++++++++++++++
+ tapset/libosmocore.stp | 18 ++++++++++++++++++
+ 7 files changed, 115 insertions(+), 2 deletions(-)
+ create mode 100644 src/probes.d
+ create mode 100644 tapset/Makefile.am
+ create mode 100644 tapset/libosmocore.stp
+
+diff --git a/Makefile.am b/Makefile.am
+index f2a05a96..ab2aad92 100644
+--- a/Makefile.am
++++ b/Makefile.am
+@@ -1,7 +1,7 @@
+ ACLOCAL_AMFLAGS = -I m4
+ 
+ AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include
+-SUBDIRS = include src src/vty src/codec src/gsm src/coding src/gb src/ctrl src/sim src/pseudotalloc src/usb utils tests
++SUBDIRS = include src src/vty src/codec src/gsm src/coding src/gb src/ctrl src/sim src/pseudotalloc src/usb utils tapset tests
+ 
+ pkgconfigdir = $(libdir)/pkgconfig
+ pkgconfig_DATA = libosmocore.pc libosmocodec.pc libosmovty.pc libosmogsm.pc \
+diff --git a/configure.ac b/configure.ac
+index b07a3bd6..e26d8a8b 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -392,6 +392,38 @@ AC_MSG_CHECKING([whether to enable ARM NEON instructions support])
+ AC_MSG_RESULT([$neon])
+ AM_CONDITIONAL(HAVE_NEON, [test "x$neon" != "xno"])
+ 
++#
++# SystemTap support
++#
++AC_MSG_CHECKING([whether to include systemtap tracing support])
++AC_ARG_ENABLE([systemtap],
++	      [AS_HELP_STRING([--enable-systemtap],
++			      [Enable inclusion of systemtap trace support])],
++	      [ENABLE_SYSTEMTAP="${enableval}"], [ENABLE_SYSTEMTAP='no'])
++AM_CONDITIONAL([ENABLE_SYSTEMTAP], [test x$ENABLE_SYSTEMTAP = xyes])
++AC_MSG_RESULT(${ENABLE_SYSTEMTAP})
++
++if test "x${ENABLE_SYSTEMTAP}" = xyes; then
++  # Additional configuration for --enable-systemtap is HERE
++  AC_CHECK_PROGS(DTRACE, dtrace)
++  if test -z "$DTRACE"; then
++    AC_MSG_ERROR([dtrace not found])
++  fi
++  AC_CHECK_HEADER([sys/sdt.h], [SDT_H_FOUND='yes'],
++                [SDT_H_FOUND='no';
++                   AC_MSG_ERROR([systemtap support needs sys/sdt.h header])])
++  AC_DEFINE([HAVE_SYSTEMTAP], [1], [Define to 1 if using SystemTap probes.])
++  AC_ARG_WITH([tapset-install-dir],
++	      [AS_HELP_STRING([--with-tapset-install-dir],
++	         [The absolute path where the tapset dir will be installed])],
++	      [if test "x${withval}" = x; then
++		 ABS_TAPSET_DIR="\$(datadir)/systemtap/tapset"
++	       else
++		 ABS_TAPSET_DIR="${withval}"
++	       fi], [ABS_TAPSET_DIR="\$(datadir)/systemtap/tapset"])
++  AC_SUBST(ABS_TAPSET_DIR)
++fi
++
+ 
+ OSMO_AC_CODE_COVERAGE
+ 
+@@ -446,6 +478,7 @@ AC_OUTPUT(
+ 	src/gb/Makefile
+ 	src/ctrl/Makefile
+ 	src/pseudotalloc/Makefile
++	tapset/Makefile
+ 	tests/Makefile
+ 	tests/atlocal
+ 	utils/Makefile
+diff --git a/src/Makefile.am b/src/Makefile.am
+index 891b4a6f..f03ce559 100644
+--- a/src/Makefile.am
++++ b/src/Makefile.am
+@@ -28,6 +28,7 @@ libosmocore_la_SOURCES = context.c timer.c timer_gettimeofday.c timer_clockgetti
+ 			 sockaddr_str.c \
+ 			 use_count.c \
+ 			 exec.c \
++			 probes.d \
+ 			 $(NULL)
+ 
+ if HAVE_SSSE3
+@@ -71,5 +72,16 @@ if ENABLE_SERIAL
+ libosmocore_la_SOURCES += serial.c
+ endif
+ 
++if ENABLE_SYSTEMTAP
++probes.h: probes.d
++	$(DTRACE) -C -h -s $< -o $@
++
++probes.lo: probes.d
++	$(LIBTOOL) --mode=compile $(AM_V_lt) --tag=CC env CFLAGS="$(CFLAGS)" $(DTRACE) -C -G -s $< -o $@
++
++BUILT_SOURCES += probes.h probes.lo
++libosmocore_la_LIBADD += probes.lo
++endif
++
+ crc%gen.c: crcXXgen.c.tpl
+ 	$(AM_V_GEN)sed -e's/XX/$*/g' $< > $@
+diff --git a/src/logging.c b/src/logging.c
+index 212b0b99..b480f0b5 100644
+--- a/src/logging.c
++++ b/src/logging.c
+@@ -44,6 +44,17 @@
+ #include <syslog.h>
+ #endif
+ 
++#ifdef HAVE_SYSTEMTAP
++/* include the generated probes header and put markers in code */
++#include "probes.h"
++#define TRACE(probe) probe
++#define TRACE_ENABLED(probe) probe ## _ENABLED()
++#else
++/* Wrap the probe to allow it to be removed when no systemtap available */
++#define TRACE(probe)
++#define TRACE_ENABLED(probe) (0)
++#endif /* HAVE_SYSTEMTAP */
++
+ #include <time.h>
+ #include <sys/time.h>
+ #include <errno.h>
+@@ -642,9 +653,11 @@ void logp2(int subsys, unsigned int level, const char *file, int line, int cont,
+ {
+ 	va_list ap;
+ 
++	LIBOSMOCORE_LOG_START();
+ 	va_start(ap, format);
+ 	osmo_vlogp(subsys, level, file, line, cont, format, ap);
+ 	va_end(ap);
++	LIBOSMOCORE_LOG_DONE();
+ }
+ 
+ /*! Register a new log target with the logging core
+@@ -831,6 +844,14 @@ void log_set_category_filter(struct log_target *target, int category,
+ }
+ 
+ #if (!EMBEDDED)
++static void _stderr_output(struct log_target *target, unsigned int level,
++			 const char *log)
++{
++	LIBOSMOCORE_STDERR_START(strlen(log));
++	fprintf(target->tgt_file.out, "%s", log);
++	fflush(target->tgt_file.out);
++	LIBOSMOCORE_STDERR_DONE();
++}
+ static void _file_output(struct log_target *target, unsigned int level,
+ 			 const char *log)
+ {
+@@ -898,7 +919,7 @@ struct log_target *log_target_create_stderr(void)
+ 
+ 	target->type = LOG_TGT_TYPE_STDERR;
+ 	target->tgt_file.out = stderr;
+-	target->output = _file_output;
++	target->output = _stderr_output;
+ 	return target;
+ #else
+ 	return NULL;
+diff --git a/src/probes.d b/src/probes.d
+new file mode 100644
+index 00000000..12840577
+--- /dev/null
++++ b/src/probes.d
+@@ -0,0 +1,7 @@
++provider libosmocore {
++	probe stderr_start(int); /* (int number of octets) */
++	probe stderr_done()
++
++	probe log_start();
++	probe log_done()
++};
+diff --git a/tapset/Makefile.am b/tapset/Makefile.am
+new file mode 100644
+index 00000000..a07a3b1d
+--- /dev/null
++++ b/tapset/Makefile.am
+@@ -0,0 +1,22 @@
++.PHONY: clean-local install-data-hook uninstall-local
++
++EXTRA_DIST = libosmocore.stp
++TAPSET_FILES = $(EXTRA_DIST)
++TAPSET_INSTALL_DIR = $(DESTDIR)@ABS_TAPSET_DIR@
++
++if ENABLE_SYSTEMTAP
++all-local: $(TAPSET_FILES)
++
++clean-local:
++
++install-data-hook:
++	$(MKDIR_P) $(TAPSET_INSTALL_DIR)
++	$(INSTALL_DATA) $(TAPSET_FILES) $(TAPSET_INSTALL_DIR)
++
++uninstall-local:
++	@list='$(TAPSET_FILES)'; for p in $$list; do \
++	  echo " rm -f '$(TAPSET_INSTALL_DIR)/$$p'"; \
++	  rm -f "$(TAPSET_INSTALL_DIR)/$$p"; \
++	done
++
++endif
+diff --git a/tapset/libosmocore.stp b/tapset/libosmocore.stp
+new file mode 100644
+index 00000000..10fa7b24
+--- /dev/null
++++ b/tapset/libosmocore.stp
+@@ -0,0 +1,18 @@
++/* libosmocore tapset
++ *
++ * This file is part of libosmocore.
++ *
++ * Each probe defines the probe name and a full probestr which consist of the probe name and between
++ * brackets all argument names and values.
++ */
++
++probe libosmocore_stderr_start = process("libosmocore").mark("stderr_start")
++{
++ count = $arg1;
++ probestr = sprintf("%s(count=%d), $$name, count);
++}
++
++probe libosmocore_stderr_done = process("libosmocore").mark("stderr_done")
++{
++ probestr = sprintf("%s", $$name);
++}
+-- 
+2.28.0
+