From e0f3e56ce5a41661917935b9ce3ae8d1f31d59cd Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Sat, 22 May 2010 17:52:39 +0100 Subject: [PATCH] trace: Add trace-events file for declaring trace events 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 and Blue Swirl . Signed-off-by: Stefan Hajnoczi --- .gitignore | 2 + Makefile | 17 ++++-- Makefile.objs | 5 ++ Makefile.target | 1 + configure | 18 ++++++ trace-events | 24 ++++++++ tracetool | 175 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 238 insertions(+), 4 deletions(-) create mode 100644 trace-events create mode 100755 tracetool diff --git a/.gitignore b/.gitignore index ec6f89f..f3f2bb7 100644 --- a/.gitignore +++ b/.gitignore @@ -2,6 +2,8 @@ config-devices.* config-all-devices.* config-host.* config-target.* +trace.h +trace.c *-softmmu *-darwin-user *-linux-user diff --git a/Makefile b/Makefile index f95cc2f..3c5e6a0 100644 --- a/Makefile +++ b/Makefile @@ -1,6 +1,6 @@ # 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. @@ -104,16 +104,24 @@ ui/vnc.o: QEMU_CFLAGS += $(VNC_TLS_CFLAGS) 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 $@") @@ -133,6 +141,7 @@ clean: 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 $@ || exit 1; fi; \ diff --git a/Makefile.objs b/Makefile.objs index 4a1eaa1..c61332d 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -265,6 +265,11 @@ libdis-$(CONFIG_S390_DIS) += s390-dis.o 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) diff --git a/Makefile.target b/Makefile.target index 18826bb..a4e80b1 100644 --- a/Makefile.target +++ b/Makefile.target @@ -310,6 +310,7 @@ obj-y += $(addprefix $(HWDIR)/, $(hw-obj-y)) 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) diff --git a/configure b/configure index 146dac0..38613c3 100755 --- a/configure +++ b/configure @@ -317,6 +317,7 @@ pkgversion="" check_utests="no" user_pie="no" zero_malloc="" +trace_backend="nop" # OS specific if check_define __linux__ ; then @@ -519,6 +520,8 @@ for opt do ;; --target-list=*) target_list="$optarg" ;; + --trace-backend=*) trace_backend="$optarg" + ;; --enable-gprof) gprof="yes" ;; --static) @@ -897,6 +900,7 @@ echo " --enable-docs enable documentation build" 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 @@ -2059,6 +2063,18 @@ if compile_prog "" "" ; then 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 @@ -2189,6 +2205,7 @@ echo "preadv support $preadv" echo "fdatasync $fdatasync" echo "uuid support $uuid" echo "vhost-net support $vhost_net" +echo "Trace backend $trace_backend" if test $sdl_too_old = "yes"; then echo "-> Your SDL version is too old - please upgrade to have SDL support" @@ -2450,6 +2467,7 @@ bsd) ;; esac +echo "TRACE_BACKEND=$trace_backend" >> $config_host_mak echo "TOOLS=$tools" >> $config_host_mak echo "ROMS=$roms" >> $config_host_mak echo "MAKE=$make" >> $config_host_mak diff --git a/trace-events b/trace-events new file mode 100644 index 0000000..a37d3cc --- /dev/null +++ b/trace-events @@ -0,0 +1,24 @@ +# 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: +# +# ( [, ] ...) "" +# +# Example: qemu_malloc(size_t size) "size %zu" +# +# The 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 should be a sprintf()-compatible format string. diff --git a/tracetool b/tracetool new file mode 100755 index 0000000..01de580 --- /dev/null +++ b/tracetool @@ -0,0 +1,175 @@ +#!/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 <