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authorLluís Vilanova <vilanova@ac.upc.edu>2014-05-27 15:02:14 +0200
committerStefan Hajnoczi <stefanha@redhat.com>2014-06-09 15:43:40 +0200
commit5b808275f3bbe8cc95bb9301f4d5a41331d0e0e6 (patch)
treed5611a010851864336448529088cd94a9afcf83a /trace
parent82432638ebeedda8a2e18838b6fbef4b14a94f31 (diff)
downloadqemu-arm-5b808275f3bbe8cc95bb9301f4d5a41331d0e0e6.tar.gz
trace: Multi-backend tracing
Adds support to compile QEMU with multiple tracing backends at the same time. For example, you can compile QEMU with: $ ./configure --enable-trace-backends=ftrace,dtrace Where 'ftrace' can be handy for having an in-flight record of events, and 'dtrace' can be later used to extract more information from the system. This patch allows having both available without recompiling QEMU. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'trace')
-rw-r--r--trace/Makefile.objs32
-rw-r--r--trace/control-internal.h4
-rw-r--r--trace/control.c49
-rw-r--r--trace/control.h27
-rw-r--r--trace/default.c40
-rw-r--r--trace/ftrace.c25
-rw-r--r--trace/ftrace.h5
-rw-r--r--trace/simple.c19
-rw-r--r--trace/simple.h1
-rw-r--r--trace/stderr.c30
10 files changed, 76 insertions, 156 deletions
diff --git a/trace/Makefile.objs b/trace/Makefile.objs
index 6a30467096..d7a86969a4 100644
--- a/trace/Makefile.objs
+++ b/trace/Makefile.objs
@@ -3,12 +3,12 @@
######################################################################
# Auto-generated event descriptions for LTTng ust code
-ifeq ($(TRACE_BACKEND),ust)
+ifeq ($(findstring ust,$(TRACE_BACKENDS)),ust)
$(obj)/generated-ust-provider.h: $(obj)/generated-ust-provider.h-timestamp
$(obj)/generated-ust-provider.h-timestamp: $(SRC_PATH)/trace-events
$(call quiet-command,$(TRACETOOL) \
--format=ust-events-h \
- --backend=$(TRACE_BACKEND) \
+ --backends=$(TRACE_BACKENDS) \
< $< > $@," GEN $(patsubst %-timestamp,%,$@)")
@cmp -s $@ $(patsubst %-timestamp,%,$@) || cp $@ $(patsubst %-timestamp,%,$@)
@@ -16,7 +16,7 @@ $(obj)/generated-ust.c: $(obj)/generated-ust.c-timestamp $(BUILD_DIR)/config-hos
$(obj)/generated-ust.c-timestamp: $(SRC_PATH)/trace-events
$(call quiet-command,$(TRACETOOL) \
--format=ust-events-c \
- --backend=$(TRACE_BACKEND) \
+ --backends=$(TRACE_BACKENDS) \
< $< > $@," GEN $(patsubst %-timestamp,%,$@)")
@cmp -s $@ $(patsubst %-timestamp,%,$@) || cp $@ $(patsubst %-timestamp,%,$@)
@@ -31,7 +31,7 @@ $(obj)/generated-events.h: $(obj)/generated-events.h-timestamp
$(obj)/generated-events.h-timestamp: $(SRC_PATH)/trace-events
$(call quiet-command,$(TRACETOOL) \
--format=events-h \
- --backend=$(TRACE_BACKEND) \
+ --backends=$(TRACE_BACKENDS) \
< $< > $@," GEN $(patsubst %-timestamp,%,$@)")
@cmp -s $@ $(patsubst %-timestamp,%,$@) || cp $@ $(patsubst %-timestamp,%,$@)
@@ -39,7 +39,7 @@ $(obj)/generated-events.c: $(obj)/generated-events.c-timestamp $(BUILD_DIR)/conf
$(obj)/generated-events.c-timestamp: $(SRC_PATH)/trace-events
$(call quiet-command,$(TRACETOOL) \
--format=events-c \
- --backend=$(TRACE_BACKEND) \
+ --backends=$(TRACE_BACKENDS) \
< $< > $@," GEN $(patsubst %-timestamp,%,$@)")
@cmp -s $@ $(patsubst %-timestamp,%,$@) || cp $@ $(patsubst %-timestamp,%,$@)
@@ -54,23 +54,21 @@ $(obj)/generated-tracers.h: $(obj)/generated-tracers.h-timestamp
$(obj)/generated-tracers.h-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak
$(call quiet-command,$(TRACETOOL) \
--format=h \
- --backend=$(TRACE_BACKEND) \
+ --backends=$(TRACE_BACKENDS) \
< $< > $@," GEN $(patsubst %-timestamp,%,$@)")
######################################################################
# Auto-generated tracing routines (non-DTrace)
-ifneq ($(TRACE_BACKEND),dtrace)
$(obj)/generated-tracers.c: $(obj)/generated-tracers.c-timestamp
@cmp -s $< $@ || cp $< $@
$(obj)/generated-tracers.c-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak
$(call quiet-command,$(TRACETOOL) \
--format=c \
- --backend=$(TRACE_BACKEND) \
+ --backends=$(TRACE_BACKENDS) \
< $< > $@," GEN $(patsubst %-timestamp,%,$@)")
$(obj)/generated-tracers.o: $(obj)/generated-tracers.c $(obj)/generated-tracers.h
-endif
######################################################################
@@ -79,27 +77,27 @@ endif
# Normal practice is to name DTrace probe file with a '.d' extension
# but that gets picked up by QEMU's Makefile as an external dependency
# rule file. So we use '.dtrace' instead
-ifeq ($(TRACE_BACKEND),dtrace)
-$(obj)/generated-tracers.dtrace: $(obj)/generated-tracers.dtrace-timestamp
-$(obj)/generated-tracers.dtrace-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak
+ifeq ($(findstring dtrace,$(TRACE_BACKENDS)),dtrace)
+$(obj)/generated-tracers-dtrace.dtrace: $(obj)/generated-tracers-dtrace.dtrace-timestamp
+$(obj)/generated-tracers-dtrace.dtrace-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak
$(call quiet-command,$(TRACETOOL) \
--format=d \
- --backend=$(TRACE_BACKEND) \
+ --backends=$(TRACE_BACKENDS) \
< $< > $@," GEN $(patsubst %-timestamp,%,$@)")
@cmp -s $@ $(patsubst %-timestamp,%,$@) || cp $@ $(patsubst %-timestamp,%,$@)
-$(obj)/generated-tracers-dtrace.h: $(obj)/generated-tracers.dtrace
+$(obj)/generated-tracers-dtrace.h: $(obj)/generated-tracers-dtrace.dtrace
$(call quiet-command,dtrace -o $@ -h -s $<, " GEN $@")
-$(obj)/generated-tracers.o: $(obj)/generated-tracers.dtrace
+$(obj)/generated-tracers-dtrace.o: $(obj)/generated-tracers-dtrace.dtrace
+
+util-obj-y += generated-tracers-dtrace.o
endif
######################################################################
# Backend code
-util-obj-$(CONFIG_TRACE_DEFAULT) += default.o
util-obj-$(CONFIG_TRACE_SIMPLE) += simple.o
-util-obj-$(CONFIG_TRACE_STDERR) += stderr.o
util-obj-$(CONFIG_TRACE_FTRACE) += ftrace.o
util-obj-$(CONFIG_TRACE_UST) += generated-ust.o
util-obj-y += control.o
diff --git a/trace/control-internal.h b/trace/control-internal.h
index b3f587ed93..5a8df28c58 100644
--- a/trace/control-internal.h
+++ b/trace/control-internal.h
@@ -1,7 +1,7 @@
/*
* Interface for configuring and controlling the state of tracing events.
*
- * Copyright (C) 2011-2012 Lluís Vilanova <vilanova@ac.upc.edu>
+ * Copyright (C) 2011-2014 Lluís Vilanova <vilanova@ac.upc.edu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
@@ -61,7 +61,7 @@ static inline void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
{
assert(ev != NULL);
assert(trace_event_get_state_static(ev));
- return trace_event_set_state_dynamic_backend(ev, state);
+ ev->dstate = state;
}
#endif /* TRACE__CONTROL_INTERNAL_H */
diff --git a/trace/control.c b/trace/control.c
index 4aa02cf2d6..45e6604ec9 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -1,13 +1,19 @@
/*
* Interface for configuring and controlling the state of tracing events.
*
- * Copyright (C) 2011-2012 Lluís Vilanova <vilanova@ac.upc.edu>
+ * Copyright (C) 2011-2014 Lluís Vilanova <vilanova@ac.upc.edu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "trace/control.h"
+#ifdef CONFIG_TRACE_SIMPLE
+#include "trace/simple.h"
+#endif
+#ifdef CONFIG_TRACE_FTRACE
+#include "trace/ftrace.h"
+#endif
TraceEvent *trace_event_name(const char *name)
@@ -79,7 +85,20 @@ TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev)
return NULL;
}
-void trace_backend_init_events(const char *fname)
+void trace_print_events(FILE *stream, fprintf_function stream_printf)
+{
+ TraceEventID i;
+
+ for (i = 0; i < trace_event_count(); i++) {
+ TraceEvent *ev = trace_event_id(i);
+ stream_printf(stream, "%s [Event ID %u] : state %u\n",
+ trace_event_get_name(ev), i,
+ trace_event_get_state_static(ev) &&
+ trace_event_get_state_dynamic(ev));
+ }
+}
+
+static void trace_init_events(const char *fname)
{
if (fname == NULL) {
return;
@@ -130,3 +149,29 @@ void trace_backend_init_events(const char *fname)
exit(1);
}
}
+
+bool trace_init_backends(const char *events, const char *file)
+{
+#ifdef CONFIG_TRACE_SIMPLE
+ if (!st_init(file)) {
+ fprintf(stderr, "failed to initialize simple tracing backend.\n");
+ return false;
+ }
+#else
+ if (file) {
+ fprintf(stderr, "error: -trace file=...: "
+ "option not supported by the selected tracing backends\n");
+ return false;
+ }
+#endif
+
+#ifdef CONFIG_TRACE_FTRACE
+ if (!ftrace_init()) {
+ fprintf(stderr, "failed to initialize ftrace backend.\n");
+ return false;
+ }
+#endif
+
+ trace_init_events(events);
+ return true;
+}
diff --git a/trace/control.h b/trace/control.h
index cde8260a8a..e1ec033705 100644
--- a/trace/control.h
+++ b/trace/control.h
@@ -1,7 +1,7 @@
/*
* Interface for configuring and controlling the state of tracing events.
*
- * Copyright (C) 2011-2012 Lluís Vilanova <vilanova@ac.upc.edu>
+ * Copyright (C) 2011-2014 Lluís Vilanova <vilanova@ac.upc.edu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
@@ -146,26 +146,17 @@ static bool trace_event_get_state_dynamic(TraceEvent *ev);
*/
static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
-/**
- * trace_event_set_state_dynamic_backend:
- *
- * Warning: This function must be implemented by each tracing backend.
- */
-void trace_event_set_state_dynamic_backend(TraceEvent *ev, bool state);
-
/**
* trace_print_events:
*
* Print the state of all events.
- *
- * Warning: This function must be implemented by each tracing backend.
*/
void trace_print_events(FILE *stream, fprintf_function stream_printf);
/**
- * trace_backend_init:
+ * trace_init_backends:
* @events: Name of file with events to be enabled at startup; may be NULL.
* Corresponds to commandline option "-trace events=...".
* @file: Name of trace output file; may be NULL.
@@ -173,19 +164,9 @@ void trace_print_events(FILE *stream, fprintf_function stream_printf);
*
* Initialize the tracing backend.
*
- * Warning: This function must be implemented by each tracing backend.
- *
- * Returns: Whether the backend could be successfully initialized.
- */
-bool trace_backend_init(const char *events, const char *file);
-
-/**
- * trace_backend_init_events:
- * @fname: Name of file with events to enable; may be NULL.
- *
- * Generic function to initialize the state of events.
+ * Returns: Whether the backends could be successfully initialized.
*/
-void trace_backend_init_events(const char *fname);
+bool trace_init_backends(const char *events, const char *file);
#include "trace/control-internal.h"
diff --git a/trace/default.c b/trace/default.c
deleted file mode 100644
index 6e07a479d6..0000000000
--- a/trace/default.c
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * Default implementation for backend initialization from commandline.
- *
- * Copyright (C) 2011-2012 Lluís Vilanova <vilanova@ac.upc.edu>
- *
- * This work is licensed under the terms of the GNU GPL, version 2. See
- * the COPYING file in the top-level directory.
- */
-
-#include "trace/control.h"
-
-
-void trace_print_events(FILE *stream, fprintf_function stream_printf)
-{
- fprintf(stderr, "warning: "
- "cannot print the trace events with the current backend\n");
- stream_printf(stream, "error: "
- "operation not supported with the current backend\n");
-}
-
-void trace_event_set_state_dynamic_backend(TraceEvent *ev, bool state)
-{
- fprintf(stderr, "warning: "
- "cannot set the state of a trace event with the current backend\n");
-}
-
-bool trace_backend_init(const char *events, const char *file)
-{
- if (events) {
- fprintf(stderr, "error: -trace events=...: "
- "option not supported by the selected tracing backend\n");
- return false;
- }
- if (file) {
- fprintf(stderr, "error: -trace file=...: "
- "option not supported by the selected tracing backend\n");
- return false;
- }
- return true;
-}
diff --git a/trace/ftrace.c b/trace/ftrace.c
index 46b7fdb1f2..a7ae371e6f 100644
--- a/trace/ftrace.c
+++ b/trace/ftrace.c
@@ -42,35 +42,13 @@ static int find_debugfs(char *debugfs)
return 1;
}
-void trace_print_events(FILE *stream, fprintf_function stream_printf)
-{
- TraceEventID i;
-
- for (i = 0; i < trace_event_count(); i++) {
- TraceEvent *ev = trace_event_id(i);
- stream_printf(stream, "%s [Event ID %u] : state %u\n",
- trace_event_get_name(ev), i, trace_event_get_state_dynamic(ev));
- }
-}
-
-void trace_event_set_state_dynamic_backend(TraceEvent *ev, bool state)
-{
- ev->dstate = state;
-}
-
-bool trace_backend_init(const char *events, const char *file)
+bool ftrace_init(void)
{
char debugfs[PATH_MAX];
char path[PATH_MAX];
int debugfs_found;
int trace_fd = -1;
- if (file) {
- fprintf(stderr, "error: -trace file=...: "
- "option not supported by the selected tracing backend\n");
- return false;
- }
-
debugfs_found = find_debugfs(debugfs);
if (debugfs_found) {
snprintf(path, PATH_MAX, "%s/tracing/tracing_on", debugfs);
@@ -97,6 +75,5 @@ bool trace_backend_init(const char *events, const char *file)
return false;
}
- trace_backend_init_events(events);
return true;
}
diff --git a/trace/ftrace.h b/trace/ftrace.h
index 94cb8d5365..863e052e90 100644
--- a/trace/ftrace.h
+++ b/trace/ftrace.h
@@ -1,10 +1,15 @@
#ifndef TRACE_FTRACE_H
#define TRACE_FTRACE_H
+#include <stdbool.h>
+
+
#define MAX_TRACE_STRLEN 512
#define _STR(x) #x
#define STR(x) _STR(x)
extern int trace_marker_fd;
+bool ftrace_init(void);
+
#endif /* ! TRACE_FTRACE_H */
diff --git a/trace/simple.c b/trace/simple.c
index 5a2e188c9a..a8f923c82e 100644
--- a/trace/simple.c
+++ b/trace/simple.c
@@ -368,22 +368,6 @@ void st_flush_trace_buffer(void)
flush_trace_file(true);
}
-void trace_print_events(FILE *stream, fprintf_function stream_printf)
-{
- unsigned int i;
-
- for (i = 0; i < trace_event_count(); i++) {
- TraceEvent *ev = trace_event_id(i);
- stream_printf(stream, "%s [Event ID %u] : state %u\n",
- trace_event_get_name(ev), i, trace_event_get_state_dynamic(ev));
- }
-}
-
-void trace_event_set_state_dynamic_backend(TraceEvent *ev, bool state)
-{
- ev->dstate = state;
-}
-
/* Helper function to create a thread with signals blocked. Use glib's
* portable threads since QEMU abstractions cannot be used due to reentrancy in
* the tracer. Also note the signal masking on POSIX hosts so that the thread
@@ -412,7 +396,7 @@ static GThread *trace_thread_create(GThreadFunc fn)
return thread;
}
-bool trace_backend_init(const char *events, const char *file)
+bool st_init(const char *file)
{
GThread *thread;
@@ -430,7 +414,6 @@ bool trace_backend_init(const char *events, const char *file)
}
atexit(st_flush_trace_buffer);
- trace_backend_init_events(events);
st_set_trace_file(file);
return true;
}
diff --git a/trace/simple.h b/trace/simple.h
index 5260d9aa81..6997996855 100644
--- a/trace/simple.h
+++ b/trace/simple.h
@@ -21,6 +21,7 @@
void st_print_trace_file_status(FILE *stream, fprintf_function stream_printf);
void st_set_trace_file_enabled(bool enable);
bool st_set_trace_file(const char *file);
+bool st_init(const char *file);
void st_flush_trace_buffer(void);
typedef struct {
diff --git a/trace/stderr.c b/trace/stderr.c
deleted file mode 100644
index e212efd64d..0000000000
--- a/trace/stderr.c
+++ /dev/null
@@ -1,30 +0,0 @@
-#include "trace.h"
-#include "trace/control.h"
-
-
-void trace_print_events(FILE *stream, fprintf_function stream_printf)
-{
- TraceEventID i;
-
- for (i = 0; i < trace_event_count(); i++) {
- TraceEvent *ev = trace_event_id(i);
- stream_printf(stream, "%s [Event ID %u] : state %u\n",
- trace_event_get_name(ev), i, trace_event_get_state_dynamic(ev));
- }
-}
-
-void trace_event_set_state_dynamic_backend(TraceEvent *ev, bool state)
-{
- ev->dstate = state;
-}
-
-bool trace_backend_init(const char *events, const char *file)
-{
- if (file) {
- fprintf(stderr, "error: -trace file=...: "
- "option not supported by the selected tracing backend\n");
- return false;
- }
- trace_backend_init_events(events);
- return true;
-}