This patch adds a simple tracer which produces binary trace files. To
try out the simple backend:
$ ./configure --trace-backend=simple
$ make
After running QEMU you can pretty-print the trace:
$ ./simpletrace.py trace-events /tmp/trace.log
The output of simpletrace.py looks like this:
qemu_realloc 0.699 ptr=0x24363f0 size=0x3 newptr=0x24363f0
qemu_free 0.768 ptr=0x24363f0
^ ^---- timestamp delta (us)
|____ trace event name
Signed-off-by: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com>
trace: Make trace record fields 64-bit
Explicitly use 64-bit fields in trace records so that timestamps and
magic numbers work for 32-bit host builds.
Includes fixes from Prerna Saxena <pre...@linux.vnet.ibm.com>.
Signed-off-by: Prerna Saxena <pre...@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com>
---
.gitignore | 1 +
Makefile | 2 +
Makefile.objs | 3 +
configure | 2 +-
simpletrace.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
simpletrace.h | 26 +++++++++++
simpletrace.py | 96 ++++++++++++++++++++++++++++++++++++++++++
tracetool | 82 ++++++++++++++++++++++++++++++++++--
8 files changed, 333 insertions(+), 6 deletions(-)
create mode 100644 simpletrace.c
create mode 100644 simpletrace.h
create mode 100755 simpletrace.py
diff --git a/.gitignore b/.gitignore
index f3f2bb7..72bff98 100644
--- a/.gitignore
+++ b/.gitignore
@@ -42,6 +42,7 @@ QMP/qmp-commands.txt
*.log
*.pdf
*.pg
+*.pyc
*.toc
*.tp
*.vr
diff --git a/Makefile b/Makefile
index 3c5e6a0..ab91d42 100644
--- a/Makefile
+++ b/Makefile
@@ -112,6 +112,8 @@ trace.c: $(SRC_PATH)/trace-events config-host.mak
trace.o: trace.c $(GENERATED_HEADERS)
+simpletrace.o: simpletrace.c $(GENERATED_HEADERS)
+
######################################################################
qemu-img.o: qemu-img-cmds.h
diff --git a/Makefile.objs b/Makefile.objs
index c61332d..3ef6d80 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -269,6 +269,9 @@ libdis-$(CONFIG_SPARC_DIS) += sparc-dis.o
# trace
trace-obj-y = trace.o
+ifeq ($(TRACE_BACKEND),simple)
+trace-obj-y += simpletrace.o
+endif
vl.o: QEMU_CFLAGS+=$(GPROF_CFLAGS)
diff --git a/configure b/configure
index d3648b2..62dd10d 100755
--- a/configure
+++ b/configure
@@ -898,7 +898,7 @@ 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 " --trace-backend=B Trace backend nop simple"
echo ""
echo "NOTE: The object files are built at the place where configure is
launched"
exit 1
diff --git a/simpletrace.c b/simpletrace.c
new file mode 100644
index 0000000..a6afc51
--- /dev/null
+++ b/simpletrace.c
@@ -0,0 +1,127 @@
+/*
+ * Simple trace backend
+ *
+ * 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.
+ *
+ */
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include "trace.h"
+
+/** Trace file header event ID */
+#define HEADER_EVENT_ID (~(uint64_t)0) /* avoids conflicting with
TraceEventIDs */
+
+/** Trace file magic number */
+#define HEADER_MAGIC 0xf2b177cb0aa429b4ULL
+
+/** Trace file version number, bump if format changes */
+#define HEADER_VERSION 0
+
+/** Trace buffer entry */
+typedef struct {
+ uint64_t event;
+ uint64_t timestamp_ns;
+ uint64_t x1;
+ uint64_t x2;
+ uint64_t x3;
+ uint64_t x4;
+ uint64_t x5;
+} TraceRecord;
+
+enum {
+ TRACE_BUF_LEN = 64 * 1024 / sizeof(TraceRecord),
+};
+
+static TraceRecord trace_buf[TRACE_BUF_LEN];
+static unsigned int trace_idx;
+static FILE *trace_fp;
+
+static bool write_header(FILE *fp)
+{
+ TraceRecord header = {
+ .event = HEADER_EVENT_ID,
+ .timestamp_ns = HEADER_MAGIC,
+ .x1 = HEADER_VERSION,
+ };
+
+ return fwrite(&header, sizeof header, 1, fp) == 1;
+}
+
+static void flush_trace_buffer(void)
+{
+ if (!trace_fp) {
+ trace_fp = fopen("/tmp/trace.log", "w");
+ if (trace_fp) {
+ write_header(trace_fp);
+ atexit(flush_trace_buffer);
+ }
+ }
+ if (trace_fp) {
+ size_t unused; /* for when fwrite(3) is declared warn_unused_result */
+ unused = fwrite(trace_buf, trace_idx * sizeof(trace_buf[0]), 1,
trace_fp);
+ }
+
+ /* Discard written trace records */
+ trace_idx = 0;
+}
+
+static void trace(TraceEventID event, unsigned long x1,
+ unsigned long x2, unsigned long x3,
+ unsigned long x4, unsigned long x5)
+{
+ TraceRecord *rec = &trace_buf[trace_idx];
+ struct timespec ts;
+
+ /* TODO Windows? It would be good to use qemu-timer here but that isn't
+ * linked into qemu-tools. Also we should avoid recursion in the tracing
+ * code, therefore it is useful to be self-contained.
+ */
+ clock_gettime(CLOCK_MONOTONIC, &ts);
+
+ rec->event = event;
+ rec->timestamp_ns = ts.tv_sec * 1000000000LL + ts.tv_nsec;
+ rec->x1 = x1;
+ rec->x2 = x2;
+ rec->x3 = x3;
+ rec->x4 = x4;
+ rec->x5 = x5;
+
+ if (++trace_idx == TRACE_BUF_LEN) {
+ flush_trace_buffer();
+ }
+}
+
+void trace0(TraceEventID event)
+{
+ trace(event, 0, 0, 0, 0, 0);
+}
+
+void trace1(TraceEventID event, uint64_t x1)
+{
+ trace(event, x1, 0, 0, 0, 0);
+}
+
+void trace2(TraceEventID event, uint64_t x1, uint64_t x2)
+{
+ trace(event, x1, x2, 0, 0, 0);
+}
+
+void trace3(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3)
+{
+ trace(event, x1, x2, x3, 0, 0);
+}
+
+void trace4(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3,
uint64_t x4)
+{
+ trace(event, x1, x2, x3, x4, 0);
+}
+
+void trace5(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3,
uint64_t x4, uint64_t x5)
+{
+ trace(event, x1, x2, x3, x4, x5);
+}
diff --git a/simpletrace.h b/simpletrace.h
new file mode 100644
index 0000000..e4e9759
--- /dev/null
+++ b/simpletrace.h
@@ -0,0 +1,26 @@
+/*
+ * Simple trace backend
+ *
+ * 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.
+ *
+ */
+
+#ifndef SIMPLETRACE_H
+#define SIMPLETRACE_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+typedef uint64_t TraceEventID;
+
+void trace0(TraceEventID event);
+void trace1(TraceEventID event, uint64_t x1);
+void trace2(TraceEventID event, uint64_t x1, uint64_t x2);
+void trace3(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3);
+void trace4(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3,
uint64_t x4);
+void trace5(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3,
uint64_t x4, uint64_t x5);
+
+#endif /* SIMPLETRACE_H */
diff --git a/simpletrace.py b/simpletrace.py
new file mode 100755
index 0000000..fdf0eb5
--- /dev/null
+++ b/simpletrace.py
@@ -0,0 +1,96 @@
+#!/usr/bin/env python
+#
+# Pretty-printer for simple trace backend binary trace files
+#
+# 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.
+#
+# For help see docs/tracing.txt
+
+import sys
+import struct
+import re
+
+header_event_id = 0xffffffffffffffff
+header_magic = 0xf2b177cb0aa429b4
+header_version = 0
+
+trace_fmt = '=QQQQQQQ'
+trace_len = struct.calcsize(trace_fmt)
+event_re = re.compile(r'(disable\s+)?([a-zA-Z0-9_]+)\(([^)]*)\)\s+"([^"]*)"')
+
+def err(msg):
+ sys.stderr.write(msg + '\n')
+ sys.exit(1)
+
+def parse_events(fobj):
+ """Parse a trace-events file."""
+
+ def get_argnames(args):
+ """Extract argument names from a parameter list."""
+ return tuple(arg.split()[-1].lstrip('*') for arg in args.split(','))
+
+ events = {}
+ event_num = 0
+ for line in fobj:
+ m = event_re.match(line.strip())
+ if m is None:
+ continue
+
+ disable, name, args, fmt = m.groups()
+ if disable:
+ continue
+
+ events[event_num] = (name,) + get_argnames(args)
+ event_num += 1
+ return events
+
+def read_record(fobj):
+ """Deserialize a trace record from a file."""
+ s = fobj.read(trace_len)
+ if len(s) != trace_len:
+ return None
+ return struct.unpack(trace_fmt, s)
+
+def read_trace_file(fobj):
+ """Deserialize trace records from a file."""
+ header = read_record(fobj)
+ if header is None or \
+ header[0] != header_event_id or \
+ header[1] != header_magic or \
+ header[2] != header_version:
+ err('not a trace file or incompatible version')
+
+ while True:
+ rec = read_record(fobj)
+ if rec is None:
+ break
+
+ yield rec
+
+class Formatter(object):
+ def __init__(self, events):
+ self.events = events
+ self.last_timestamp = None
+
+ def format_record(self, rec):
+ if self.last_timestamp is None:
+ self.last_timestamp = rec[1]
+ delta_ns = rec[1] - self.last_timestamp
+ self.last_timestamp = rec[1]
+
+ event = self.events[rec[0]]
+ fields = [event[0], '%0.3f' % (delta_ns / 1000.0)]
+ for i in xrange(1, len(event)):
+ fields.append('%s=0x%x' % (event[i], rec[i + 1]))
+ return ' '.join(fields)
+
+if len(sys.argv) != 3:
+ err('usage: %s <trace-events> <trace-file>' % sys.argv[0])
+
+events = parse_events(open(sys.argv[1], 'r'))
+formatter = Formatter(events)
+for rec in read_trace_file(open(sys.argv[2], 'rb')):
+ print formatter.format_record(rec)
diff --git a/tracetool b/tracetool
index 86b6446..66df685 100755
--- a/tracetool
+++ b/tracetool
@@ -13,11 +13,12 @@ set -f
usage()
{
cat >&2 <<EOF
-usage: $0 --nop [-h | -c]
+usage: $0 [--nop | --simple] [-h | -c]
Generate tracing code for a file on stdin.
Backends:
- --nop Tracing disabled
+ --nop Tracing disabled
+ --simple Simple built-in backend
Output formats:
-h Generate .h file
@@ -56,16 +57,27 @@ get_argnames()
name=${field%,}
test "$field" = "$name" && continue
- echo -n "$name, "
+ printf "%s" "$name, "
done
# Last argument name
if [ "$nfields" -gt 1 ]
then
- echo -n "$name"
+ printf "%s" "$name"
fi
}
+# Get the number of arguments to a trace event
+get_argc()
+{
+ local name argc
+ argc=0
+ for name in $(get_argnames "$1"); do
+ argc=$((argc + 1))
+ done
+ echo $argc
+}
+
# Get the format string for a trace event
get_fmt()
{
@@ -115,6 +127,66 @@ linetoc_end_nop()
return
}
+linetoh_begin_simple()
+{
+ cat <<EOF
+#include "simpletrace.h"
+EOF
+
+ simple_event_num=0
+}
+
+cast_args_to_uint64_t()
+{
+ local arg
+ for arg in $(get_argnames "$1"); do
+ printf "%s" "(uint64_t)(uintptr_t)$arg"
+ done
+}
+
+linetoh_simple()
+{
+ local name args argc trace_args
+ name=$(get_name "$1")
+ args=$(get_args "$1")
+ argc=$(get_argc "$1")
+
+ trace_args="$simple_event_num"
+ if [ "$argc" -gt 0 ]
+ then
+ trace_args="$trace_args, $(cast_args_to_uint64_t "$1")"
+ fi
+
+ cat <<EOF
+static inline void trace_$name($args)
+{
+ trace$argc($trace_args);
+}
+EOF
+
+ simple_event_num=$((simple_event_num + 1))
+}
+
+linetoh_end_simple()
+{
+ return
+}
+
+linetoc_begin_simple()
+{
+ return
+}
+
+linetoc_simple()
+{
+ return
+}
+
+linetoc_end_simple()
+{
+ return
+}
+
# Process stdin by calling begin, line, and end functions for the backend
convert()
{
@@ -160,7 +232,7 @@ tracetoc()
# Choose backend
case "$1" in
-"--nop") backend="${1#--}" ;;
+"--nop" | "--simple") backend="${1#--}" ;;
*) usage ;;
esac
shift
--
1.7.1
