This patch introduces the trace-events file where trace events can be
declared like so:
qemu_malloc(size_t size) "size %zu"
qemu_free(void *ptr) "ptr %p"
These trace event declarations are processed by a new tool called
tracetool to generate code for the trace events. Trace event
declarations are independent of the backend tracing system (LTTng User
Space Tracing, ftrace markers, DTrace).
The default "nop" backend generates empty trace event functions.
Therefore trace events are disabled by default.
The trace-events file serves two purposes:
1. Adding trace events is easy. It is not necessary to understand the
details of a backend tracing system. The trace-events file is a
single location where trace events can be declared without code
duplication.
2. QEMU is not tightly coupled to one particular backend tracing system.
In order to support tracing across QEMU host platforms and to
anticipate new backend tracing systems that are currently maturing,
it is important to be flexible and not tied to one system.
This commit includes fixes from Prerna Saxena
<prerna@linux.vnet.ibm.com> and Blue Swirl <blauwirbel@gmail.com>.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
config-all-devices.*
config-host.*
config-target.*
+trace.h
+trace.c
*-softmmu
*-darwin-user
*-linux-user
# Makefile for QEMU.
-GENERATED_HEADERS = config-host.h
+GENERATED_HEADERS = config-host.h trace.h
ifneq ($(wildcard config-host.mak),)
# Put the all: rule here so that config-host.mak can contain dependencies.
bt-host.o: QEMU_CFLAGS += $(BLUEZ_CFLAGS)
+trace.h: $(SRC_PATH)/trace-events config-host.mak
+ $(call quiet-command,sh $(SRC_PATH)/tracetool --$(TRACE_BACKEND) -h < $< > $@," GEN $@")
+
+trace.c: $(SRC_PATH)/trace-events config-host.mak
+ $(call quiet-command,sh $(SRC_PATH)/tracetool --$(TRACE_BACKEND) -c < $< > $@," GEN $@")
+
+trace.o: trace.c $(GENERATED_HEADERS)
+
######################################################################
qemu-img.o: qemu-img-cmds.h
qemu-img.o qemu-tool.o qemu-nbd.o qemu-io.o: $(GENERATED_HEADERS)
-qemu-img$(EXESUF): qemu-img.o qemu-tool.o qemu-error.o $(block-obj-y) $(qobject-obj-y)
+qemu-img$(EXESUF): qemu-img.o qemu-tool.o qemu-error.o $(trace-obj-y) $(block-obj-y) $(qobject-obj-y)
-qemu-nbd$(EXESUF): qemu-nbd.o qemu-tool.o qemu-error.o $(block-obj-y) $(qobject-obj-y)
+qemu-nbd$(EXESUF): qemu-nbd.o qemu-tool.o qemu-error.o $(trace-obj-y) $(block-obj-y) $(qobject-obj-y)
-qemu-io$(EXESUF): qemu-io.o cmd.o qemu-tool.o qemu-error.o $(block-obj-y) $(qobject-obj-y)
+qemu-io$(EXESUF): qemu-io.o cmd.o qemu-tool.o qemu-error.o $(trace-obj-y) $(block-obj-y) $(qobject-obj-y)
qemu-img-cmds.h: $(SRC_PATH)/qemu-img-cmds.hx
$(call quiet-command,sh $(SRC_PATH)/hxtool -h < $< > $@," GEN $@")
rm -f *.o *.d *.a $(TOOLS) TAGS cscope.* *.pod *~ */*~
rm -f slirp/*.o slirp/*.d audio/*.o audio/*.d block/*.o block/*.d net/*.o net/*.d fsdev/*.o fsdev/*.d ui/*.o ui/*.d
rm -f qemu-img-cmds.h
+ rm -f trace.c trace.h
$(MAKE) -C tests clean
for d in $(ALL_SUBDIRS) libhw32 libhw64 libuser libdis libdis-user; do \
if test -d $$d; then $(MAKE) -C $$d $@ || exit 1; fi; \
libdis-$(CONFIG_SH4_DIS) += sh4-dis.o
libdis-$(CONFIG_SPARC_DIS) += sparc-dis.o
+######################################################################
+# trace
+
+trace-obj-y = trace.o
+
vl.o: QEMU_CFLAGS+=$(GPROF_CFLAGS)
vl.o: QEMU_CFLAGS+=$(SDL_CFLAGS)
endif # CONFIG_SOFTMMU
+obj-y += $(addprefix ../, $(trace-obj-y))
obj-$(CONFIG_GDBSTUB_XML) += gdbstub-xml.o
$(QEMU_PROG): $(obj-y) $(obj-$(TARGET_BASE_ARCH)-y)
check_utests="no"
user_pie="no"
zero_malloc=""
+trace_backend="nop"
# OS specific
if check_define __linux__ ; then
;;
--target-list=*) target_list="$optarg"
;;
+ --trace-backend=*) trace_backend="$optarg"
+ ;;
--enable-gprof) gprof="yes"
;;
--static)
echo " --disable-docs disable documentation build"
echo " --disable-vhost-net disable vhost-net acceleration support"
echo " --enable-vhost-net enable vhost-net acceleration support"
+echo " --trace-backend=B Trace backend nop"
echo ""
echo "NOTE: The object files are built at the place where configure is launched"
exit 1
fdatasync=yes
fi
+##########################################
+# check if trace backend exists
+
+sh "$source_path/tracetool" "--$trace_backend" --check-backend > /dev/null 2> /dev/null
+if test "$?" -ne 0 ; then
+ echo
+ echo "Error: invalid trace backend"
+ echo "Please choose a supported trace backend."
+ echo
+ exit 1
+fi
+
# End of CC checks
# After here, no more $cc or $ld runs
echo "fdatasync $fdatasync"
echo "uuid support $uuid"
echo "vhost-net support $vhost_net"
+echo "Trace backend $trace_backend"
if test $sdl_too_old = "yes"; then
echo "-> Your SDL version is too old - please upgrade to have SDL support"
;;
esac
+echo "TRACE_BACKEND=$trace_backend" >> $config_host_mak
echo "TOOLS=$tools" >> $config_host_mak
echo "ROMS=$roms" >> $config_host_mak
echo "MAKE=$make" >> $config_host_mak
--- /dev/null
+# Trace events for debugging and performance instrumentation
+#
+# This file is processed by the tracetool script during the build.
+#
+# To add a new trace event:
+#
+# 1. Choose a name for the trace event. Declare its arguments and format
+# string.
+#
+# 2. Call the trace event from code using trace_##name, e.g. multiwrite_cb() ->
+# trace_multiwrite_cb(). The source file must #include "trace.h".
+#
+# Format of a trace event:
+#
+# <name>(<type1> <arg1>[, <type2> <arg2>] ...) "<format-string>"
+#
+# Example: qemu_malloc(size_t size) "size %zu"
+#
+# The <name> must be a valid as a C function name.
+#
+# Types should be standard C types. Use void * for pointers because the trace
+# system may not have the necessary headers included.
+#
+# The <format-string> should be a sprintf()-compatible format string.
--- /dev/null
+#!/bin/sh
+#
+# Code generator for trace events
+#
+# Copyright IBM, Corp. 2010
+#
+# This work is licensed under the terms of the GNU GPL, version 2. See
+# the COPYING file in the top-level directory.
+
+# Disable pathname expansion, makes processing text with '*' characters simpler
+set -f
+
+usage()
+{
+ cat >&2 <<EOF
+usage: $0 --nop [-h | -c]
+Generate tracing code for a file on stdin.
+
+Backends:
+ --nop Tracing disabled
+
+Output formats:
+ -h Generate .h file
+ -c Generate .c file
+EOF
+ exit 1
+}
+
+# Get the name of a trace event
+get_name()
+{
+ echo ${1%%\(*}
+}
+
+# Get the argument list of a trace event, including types and names
+get_args()
+{
+ local args
+ args=${1#*\(}
+ args=${args%)*}
+ echo "$args"
+}
+
+# Get the argument name list of a trace event
+get_argnames()
+{
+ local nfields field name
+ nfields=0
+ for field in $(get_args "$1"); do
+ nfields=$((nfields + 1))
+
+ # Drop pointer star
+ field=${field#\*}
+
+ # Only argument names have commas at the end
+ name=${field%,}
+ test "$field" = "$name" && continue
+
+ printf "%s" "$name, "
+ done
+
+ # Last argument name
+ if [ "$nfields" -gt 1 ]
+ then
+ printf "%s" "$name"
+ fi
+}
+
+# Get the format string for a trace event
+get_fmt()
+{
+ local fmt
+ fmt=${1#*\"}
+ fmt=${fmt%\"*}
+ echo "$fmt"
+}
+
+linetoh_begin_nop()
+{
+ return
+}
+
+linetoh_nop()
+{
+ local name args
+ name=$(get_name "$1")
+ args=$(get_args "$1")
+
+ # Define an empty function for the trace event
+ cat <<EOF
+static inline void trace_$name($args)
+{
+}
+EOF
+}
+
+linetoh_end_nop()
+{
+ return
+}
+
+linetoc_begin_nop()
+{
+ return
+}
+
+linetoc_nop()
+{
+ # No need for function definitions in nop backend
+ return
+}
+
+linetoc_end_nop()
+{
+ return
+}
+
+# Process stdin by calling begin, line, and end functions for the backend
+convert()
+{
+ local begin process_line end
+ begin="lineto$1_begin_$backend"
+ process_line="lineto$1_$backend"
+ end="lineto$1_end_$backend"
+
+ "$begin"
+
+ while read -r str; do
+ # Skip comments and empty lines
+ str=${str%%#*}
+ test -z "$str" && continue
+
+ echo
+ "$process_line" "$str"
+ done
+
+ echo
+ "$end"
+}
+
+tracetoh()
+{
+ cat <<EOF
+#ifndef TRACE_H
+#define TRACE_H
+
+/* This file is autogenerated by tracetool, do not edit. */
+
+#include "qemu-common.h"
+EOF
+ convert h
+ echo "#endif /* TRACE_H */"
+}
+
+tracetoc()
+{
+ echo "/* This file is autogenerated by tracetool, do not edit. */"
+ convert c
+}
+
+# Choose backend
+case "$1" in
+"--nop") backend="${1#--}" ;;
+*) usage ;;
+esac
+shift
+
+case "$1" in
+"-h") tracetoh ;;
+"-c") tracetoc ;;
+"--check-backend") exit 0 ;; # used by ./configure to test for backend
+*) usage ;;
+esac
+
+exit 0
projects / qemu-xen-4.2-testing.git / commitdiff