trace: [tcg] Do not generate TCG code to trace dynamically-disabled events

If an event is dynamically disabled, the TCG code that calls the
execution-time tracer is not generated.

Removes the overheads of execution-time tracers for dynamically disabled
events. As a bonus, also avoids checking the event state when the
execution-time tracer is called from TCG-generated code (since otherwise
TCG would simply not call it).

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-id: 149915799921.6295.13067154430923434035.stgit@frigg.lan
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Lluís Vilanova 2017-07-04 10:46:39 +02:00 committed by Stefan Hajnoczi
parent 61a67f71dd
commit 864a2178d4
4 changed files with 41 additions and 14 deletions

View file

@ -6,7 +6,7 @@ Machinery for generating tracing-related intermediate files.
"""
__author__ = "Lluís Vilanova <vilanova@ac.upc.edu>"
__copyright__ = "Copyright 2012-2016, Lluís Vilanova <vilanova@ac.upc.edu>"
__copyright__ = "Copyright 2012-2017, Lluís Vilanova <vilanova@ac.upc.edu>"
__license__ = "GPL version 2 or (at your option) any later version"
__maintainer__ = "Stefan Hajnoczi"
@ -268,6 +268,7 @@ class Event(object):
return self._FMT.findall(self.fmt)
QEMU_TRACE = "trace_%(name)s"
QEMU_TRACE_NOCHECK = "_nocheck__" + QEMU_TRACE
QEMU_TRACE_TCG = QEMU_TRACE + "_tcg"
QEMU_DSTATE = "_TRACE_%(NAME)s_DSTATE"
QEMU_EVENT = "_TRACE_%(NAME)s_EVENT"