From 59b9e31b88c64ba0ec4ddea65df3e627c5005b32 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 21 Oct 2014 16:17:20 +0200 Subject: [PATCH 16/21] trace: add tracetool simpletrace_stap format Message-id: <1413908245-19510-4-git-send-email-stefanha@redhat.com> Patchwork-id: 61766 O-Subject: [RHEL7.1 qemu-kvm-rhev PATCH 3/8] trace: add tracetool simpletrace_stap format Bugzilla: 1155015 RH-Acked-by: Miroslav Rezanina RH-Acked-by: Paolo Bonzini RH-Acked-by: Laszlo Ersek This new tracetool "format" generates a SystemTap .stp file that outputs simpletrace binary trace data. In contrast to simpletrace or ftrace, SystemTap does not define its own trace format. All output from SystemTap is generated by .stp files. This patch lets us generate a .stp file that outputs in the simpletrace binary format. This makes it possible to reuse simpletrace.py to analyze traces recorded using SystemTap. The simpletrace binary format is especially useful for long-running traces like flight-recorder mode where string formatting can be expensive. Signed-off-by: Stefan Hajnoczi (cherry picked from commit 3f8b112d6b9ab65e165096582c78154dda1adc69) Signed-off-by: Stefan Hajnoczi Signed-off-by: Miroslav Rezanina --- scripts/tracetool/format/simpletrace_stap.py | 71 ++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 scripts/tracetool/format/simpletrace_stap.py diff --git a/scripts/tracetool/format/simpletrace_stap.py b/scripts/tracetool/format/simpletrace_stap.py new file mode 100644 index 0000000..7e44bc1 --- /dev/null +++ b/scripts/tracetool/format/simpletrace_stap.py @@ -0,0 +1,71 @@ +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +""" +Generate .stp file that outputs simpletrace binary traces (DTrace with SystemTAP only). +""" + +__author__ = "Stefan Hajnoczi " +__copyright__ = "Copyright (C) 2014, Red Hat, Inc." +__license__ = "GPL version 2 or (at your option) any later version" + +__maintainer__ = "Stefan Hajnoczi" +__email__ = "stefanha@redhat.com" + + +from tracetool import out +from tracetool.backend.dtrace import binary, probeprefix +from tracetool.backend.simple import is_string +from tracetool.format.stap import stap_escape + + +def generate(events, backend): + out('/* This file is autogenerated by tracetool, do not edit. */', + '') + + for event_id, e in enumerate(events): + if 'disable' in e.properties: + continue + + out('probe %(probeprefix)s.simpletrace.%(name)s = %(probeprefix)s.%(name)s ?', + '{', + probeprefix=probeprefix(), + name=e.name) + + # Calculate record size + sizes = ['24'] # sizeof(TraceRecord) + for type_, name in e.args: + name = stap_escape(name) + if is_string(type_): + out(' try {', + ' arg%(name)s_str = %(name)s ? user_string_n(%(name)s, 512) : ""', + ' } catch {}', + ' arg%(name)s_len = strlen(arg%(name)s_str)', + name=name) + sizes.append('4 + arg%s_len' % name) + else: + sizes.append('8') + sizestr = ' + '.join(sizes) + + # Generate format string and value pairs for record header and arguments + fields = [('8b', str(event_id)), + ('8b', 'gettimeofday_ns()'), + ('4b', sizestr), + ('4b', 'pid()')] + for type_, name in e.args: + name = stap_escape(name) + if is_string(type_): + fields.extend([('4b', 'arg%s_len' % name), + ('.*s', 'arg%s_len, arg%s_str' % (name, name))]) + else: + fields.append(('8b', name)) + + # Emit the entire record in a single SystemTap printf() + fmt_str = '%'.join(fmt for fmt, _ in fields) + arg_str = ', '.join(arg for _, arg in fields) + out(' printf("%%%(fmt_str)s", %(arg_str)s)', + fmt_str=fmt_str, arg_str=arg_str) + + out('}') + + out() -- 1.8.3.1