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[Qemu-devel] [PATCH 4/4] trace: [tcg] Do not generate TCG code to trace
|
From: |
Lluís Vilanova |
|
Subject: |
[Qemu-devel] [PATCH 4/4] trace: [tcg] Do not generate TCG code to trace dinamically-disabled events |
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Date: |
Wed, 14 Sep 2016 23:23:38 +0200 |
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User-agent: |
StGit/0.17.1-dirty |
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 <address@hidden>
---
scripts/tracetool/backend/dtrace.py | 2 +-
scripts/tracetool/backend/ftrace.py | 20 ++++++++++----------
scripts/tracetool/backend/log.py | 16 ++++++++--------
scripts/tracetool/backend/simple.py | 2 +-
scripts/tracetool/backend/syslog.py | 6 +++---
scripts/tracetool/backend/ust.py | 2 +-
scripts/tracetool/format/h.py | 23 +++++++++++++++++------
scripts/tracetool/format/tcg_h.py | 20 +++++++++++++++++---
scripts/tracetool/format/tcg_helper_c.py | 3 ++-
9 files changed, 60 insertions(+), 34 deletions(-)
diff --git a/scripts/tracetool/backend/dtrace.py
b/scripts/tracetool/backend/dtrace.py
index ab9ecfa..20242f2 100644
--- a/scripts/tracetool/backend/dtrace.py
+++ b/scripts/tracetool/backend/dtrace.py
@@ -41,6 +41,6 @@ def generate_h_begin(events):
def generate_h(event):
- out(' QEMU_%(uppername)s(%(argnames)s);',
+ out(' QEMU_%(uppername)s(%(argnames)s);',
uppername=event.name.upper(),
argnames=", ".join(event.args.names()))
diff --git a/scripts/tracetool/backend/ftrace.py
b/scripts/tracetool/backend/ftrace.py
index 80dcf30..d798c71 100644
--- a/scripts/tracetool/backend/ftrace.py
+++ b/scripts/tracetool/backend/ftrace.py
@@ -30,17 +30,17 @@ def generate_h(event):
if len(event.args) > 0:
argnames = ", " + argnames
- out(' {',
- ' char ftrace_buf[MAX_TRACE_STRLEN];',
- ' int unused __attribute__ ((unused));',
- ' int trlen;',
- ' if (trace_event_get_state(%(event_id)s)) {',
- ' trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
- ' "%(name)s " %(fmt)s "\\n"
%(argnames)s);',
- ' trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
- ' unused = write(trace_marker_fd, ftrace_buf, trlen);',
- ' }',
+ out(' {',
+ ' char ftrace_buf[MAX_TRACE_STRLEN];',
+ ' int unused __attribute__ ((unused));',
+ ' int trlen;',
+ ' if (trace_event_get_state(%(event_id)s)) {',
+ ' trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
+ ' "%(name)s " %(fmt)s "\\n"
%(argnames)s);',
+ ' trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
+ ' unused = write(trace_marker_fd, ftrace_buf, trlen);',
' }',
+ ' }',
name=event.name,
args=event.args,
event_id="TRACE_" + event.name.upper(),
diff --git a/scripts/tracetool/backend/log.py b/scripts/tracetool/backend/log.py
index b3ff064..6818147 100644
--- a/scripts/tracetool/backend/log.py
+++ b/scripts/tracetool/backend/log.py
@@ -36,14 +36,14 @@ def generate_h(event):
else:
cond = "trace_event_get_state(%s)" % ("TRACE_" + event.name.upper())
- out(' if (%(cond)s) {',
- ' struct timeval _now;',
- ' gettimeofday(&_now, NULL);',
- ' qemu_log_mask(LOG_TRACE, "address@hidden:%(name)s "
%(fmt)s "\\n",',
- ' getpid(),',
- ' (size_t)_now.tv_sec, (size_t)_now.tv_usec',
- ' %(argnames)s);',
- ' }',
+ out(' if (%(cond)s) {',
+ ' struct timeval _now;',
+ ' gettimeofday(&_now, NULL);',
+ ' qemu_log_mask(LOG_TRACE, "address@hidden:%(name)s " %(fmt)s
"\\n",',
+ ' getpid(),',
+ ' (size_t)_now.tv_sec, (size_t)_now.tv_usec',
+ ' %(argnames)s);',
+ ' }',
cond=cond,
name=event.name,
fmt=event.fmt.rstrip("\n"),
diff --git a/scripts/tracetool/backend/simple.py
b/scripts/tracetool/backend/simple.py
index 1bccada..4acf23f 100644
--- a/scripts/tracetool/backend/simple.py
+++ b/scripts/tracetool/backend/simple.py
@@ -36,7 +36,7 @@ def generate_h_begin(events):
def generate_h(event):
- out(' _simple_%(api)s(%(args)s);',
+ out(' _simple_%(api)s(%(args)s);',
api=event.api(),
args=", ".join(event.args.names()))
diff --git a/scripts/tracetool/backend/syslog.py
b/scripts/tracetool/backend/syslog.py
index 89019bc..b355121 100644
--- a/scripts/tracetool/backend/syslog.py
+++ b/scripts/tracetool/backend/syslog.py
@@ -36,9 +36,9 @@ def generate_h(event):
else:
cond = "trace_event_get_state(%s)" % ("TRACE_" + event.name.upper())
- out(' if (%(cond)s) {',
- ' syslog(LOG_INFO, "%(name)s " %(fmt)s %(argnames)s);',
- ' }',
+ out(' if (%(cond)s) {',
+ ' syslog(LOG_INFO, "%(name)s " %(fmt)s %(argnames)s);',
+ ' }',
cond=cond,
name=event.name,
fmt=event.fmt.rstrip("\n"),
diff --git a/scripts/tracetool/backend/ust.py b/scripts/tracetool/backend/ust.py
index ed4c227..88d13e2 100644
--- a/scripts/tracetool/backend/ust.py
+++ b/scripts/tracetool/backend/ust.py
@@ -30,6 +30,6 @@ def generate_h(event):
if len(event.args) > 0:
argnames = ", " + argnames
- out(' tracepoint(qemu, %(name)s%(tp_args)s);',
+ out(' tracepoint(qemu, %(name)s%(tp_args)s);',
name=event.name,
tp_args=argnames)
diff --git a/scripts/tracetool/format/h.py b/scripts/tracetool/format/h.py
index 3763e9a..99fcbc0 100644
--- a/scripts/tracetool/format/h.py
+++ b/scripts/tracetool/format/h.py
@@ -29,6 +29,19 @@ def generate(events, backend):
backend.generate_begin(events)
for e in events:
+ # tracer without checks
+ out('',
+ 'static inline void __nocheck__%(api)s(%(args)s)',
+ '{',
+ api=e.api(),
+ args=e.args)
+
+ if "disable" not in e.properties:
+ backend.generate(e)
+
+ out('}')
+
+ # tracer wrapper with checks (per-vCPU tracing)
if "vcpu" in e.properties:
trace_cpu = next(iter(e.args))[1]
cond = "trace_event_get_vcpu_state(%(cpu)s,"\
@@ -44,16 +57,14 @@ def generate(events, backend):
'static inline void %(api)s(%(args)s)',
'{',
' if (%(cond)s) {',
+ ' __nocheck__%(api)s(%(names)s);',
+ ' }',
+ '}',
api=e.api(),
args=e.args,
+ names=", ".join(e.args.names()),
cond=cond)
- if "disable" not in e.properties:
- backend.generate(e)
-
- out(' }',
- '}')
-
backend.generate_end(events)
out('#endif /* TRACE__GENERATED_TRACERS_H */')
diff --git a/scripts/tracetool/format/tcg_h.py
b/scripts/tracetool/format/tcg_h.py
index e2331f2..fb2503a 100644
--- a/scripts/tracetool/format/tcg_h.py
+++ b/scripts/tracetool/format/tcg_h.py
@@ -41,7 +41,7 @@ def generate(events, backend):
for e in events:
# just keep one of them
- if "tcg-trans" not in e.properties:
+ if "tcg-exec" not in e.properties:
continue
out('static inline void %(name_tcg)s(%(args)s)',
@@ -53,12 +53,26 @@ def generate(events, backend):
args_trans = e.original.event_trans.args
args_exec = tracetool.vcpu.transform_args(
"tcg_helper_c", e.original.event_exec, "wrapper")
+ if "vcpu" in e.properties:
+ trace_cpu = e.args.names()[0]
+ cond = "trace_event_get_vcpu_state(%(cpu)s,"\
+ " TRACE_%(id)s,"\
+ " TRACE_VCPU_%(id)s)"\
+ % dict(
+ cpu=trace_cpu,
+ id=e.original.event_exec.name.upper())
+ else:
+ cond = "true"
+
out(' %(name_trans)s(%(argnames_trans)s);',
- ' gen_helper_%(name_exec)s(%(argnames_exec)s);',
+ ' if (%(cond)s) {',
+ ' gen_helper_%(name_exec)s(%(argnames_exec)s);',
+ ' }',
name_trans=e.original.event_trans.api(e.QEMU_TRACE),
name_exec=e.original.event_exec.api(e.QEMU_TRACE),
argnames_trans=", ".join(args_trans.names()),
- argnames_exec=", ".join(args_exec.names()))
+ argnames_exec=", ".join(args_exec.names()),
+ cond=cond)
out('}')
diff --git a/scripts/tracetool/format/tcg_helper_c.py
b/scripts/tracetool/format/tcg_helper_c.py
index e3485b7..f9adb3c 100644
--- a/scripts/tracetool/format/tcg_helper_c.py
+++ b/scripts/tracetool/format/tcg_helper_c.py
@@ -66,7 +66,8 @@ def generate(events, backend):
out('void %(name_tcg)s(%(args_api)s)',
'{',
- ' %(name)s(%(args_call)s);',
+ # NOTE: the check was already performed at TCG-generation time
+ ' __nocheck__%(name)s(%(args_call)s);',
'}',
name_tcg="helper_%s_proxy" % e.api(),
name=e.api(),