From edb47ec498a5c00607e8d428668d5141822a9eac Mon Sep 17 00:00:00 2001
From: Lluís
Date: Wed, 31 Aug 2011 20:30:57 +0200
Subject: trace: move backend-specific code into the trace/ directory

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 scripts/tracetool | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'scripts')

diff --git a/scripts/tracetool b/scripts/tracetool
index 2155a57df2..9ed4fae70f 100755
--- a/scripts/tracetool
+++ b/scripts/tracetool
@@ -158,7 +158,7 @@ linetoc_end_nop()
 linetoh_begin_simple()
 {
     cat <<EOF
-#include "simpletrace.h"
+#include "trace/simple.h"
 EOF
 
     simple_event_num=0
-- 
cgit v1.2.3-55-g7522


From 49926043c1319ce99481d45c87c602c20b9dbb79 Mon Sep 17 00:00:00 2001
From: Lluís
Date: Wed, 31 Aug 2011 20:31:10 +0200
Subject: trace: generalize the "property" concept in the trace-events file

This adds/modifies the following functions:

* get_name: Get _only_ the event name
* has_property: Return whether an event has a property (keyword before the event
  name)

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 docs/tracing.txt  |  4 +--
 scripts/tracetool | 73 +++++++++++++++++++++++++------------------------------
 2 files changed, 35 insertions(+), 42 deletions(-)

(limited to 'scripts')

diff --git a/docs/tracing.txt b/docs/tracing.txt
index c99a0f27cf..1ad106a5d7 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -38,7 +38,7 @@ generate code for the trace events.  Trace events are invoked directly from
 source code like this:
 
     #include "trace.h"  /* needed for trace event prototype */
-
+    
     void *qemu_malloc(size_t size)
     {
         void *ptr;
@@ -103,7 +103,7 @@ portability macros, ensure they are preceded and followed by double quotes:
 4. Name trace events after their function.  If there are multiple trace events
    in one function, append a unique distinguisher at the end of the name.
 
-5. Declare trace events with the "disable" keyword.  Some trace events can
+5. Declare trace events with the "disable" property.  Some trace events can
    produce a lot of output and users are typically only interested in a subset
    of trace events.  Marking trace events disabled by default saves the user
    from having to manually disable noisy trace events.
diff --git a/scripts/tracetool b/scripts/tracetool
index 9ed4fae70f..e649a5b807 100755
--- a/scripts/tracetool
+++ b/scripts/tracetool
@@ -43,7 +43,26 @@ EOF
 # Get the name of a trace event
 get_name()
 {
-    echo ${1%%\(*}
+    local name
+    name=${1%%\(*}
+    echo "${name##* }"
+}
+
+# Get the given property of a trace event
+# 1: trace-events line
+# 2: property name
+# -> return 0 if property is present, or 1 otherwise
+has_property()
+{
+    local props prop
+    props=${1%%\(*}
+    props=${props% *}
+    for prop in $props; do
+        if [ "$prop" = "$2" ]; then
+            return 0
+        fi
+    done
+    return 1
 }
 
 # Get the argument list of a trace event, including types and names
@@ -101,20 +120,6 @@ get_fmt()
     echo "$fmt"
 }
 
-# Get the state of a trace event
-get_state()
-{
-    local str disable state
-    str=$(get_name "$1")
-    disable=${str##disable }
-    if [ "$disable" = "$str" ] ; then
-        state=1
-    else
-        state=0
-    fi
-    echo "$state"
-}
-
 linetoh_begin_nop()
 {
     return
@@ -174,14 +179,10 @@ cast_args_to_uint64_t()
 
 linetoh_simple()
 {
-    local name args argc trace_args state
+    local name args argc trace_args
     name=$(get_name "$1")
     args=$(get_args "$1")
     argc=$(get_argc "$1")
-    state=$(get_state "$1")
-    if [ "$state" = "0" ]; then
-        name=${name##disable }
-    fi
 
     trace_args="$simple_event_num"
     if [ "$argc" -gt 0 ]
@@ -222,9 +223,10 @@ linetoc_simple()
 {
     local name state
     name=$(get_name "$1")
-    state=$(get_state "$1")
-    if [ "$state" = "0" ] ; then
-        name=${name##disable }
+    if has_property "$1" "disable"; then
+        state="0"
+    else
+        state="1"
     fi
     cat <<EOF
 {.tp_name = "$name", .state=$state},
@@ -379,14 +381,10 @@ EOF
 
 linetoh_dtrace()
 {
-    local name args argnames state nameupper
+    local name args argnames nameupper
     name=$(get_name "$1")
     args=$(get_args "$1")
     argnames=$(get_argnames "$1", ",")
-    state=$(get_state "$1")
-    if [ "$state" = "0" ] ; then
-        name=${name##disable }
-    fi
 
     nameupper=`echo $name | tr '[:lower:]' '[:upper:]'`
 
@@ -430,13 +428,9 @@ EOF
 
 linetod_dtrace()
 {
-    local name args state
+    local name args
     name=$(get_name "$1")
     args=$(get_args "$1")
-    state=$(get_state "$1")
-    if [ "$state" = "0" ] ; then
-        name=${name##disable }
-    fi
 
     # DTrace provider syntax expects foo() for empty
     # params, not foo(void)
@@ -464,14 +458,10 @@ linetostap_begin_dtrace()
 
 linetostap_dtrace()
 {
-    local i arg name args arglist state
+    local i arg name args arglist
     name=$(get_name "$1")
     args=$(get_args "$1")
     arglist=$(get_argnames "$1", "")
-    state=$(get_state "$1")
-    if [ "$state" = "0" ] ; then
-        name=${name##disable }
-    fi
 
     # Define prototype for probe arguments
     cat <<EOF
@@ -517,9 +507,12 @@ convert()
         test -z "${str%%#*}" && continue
 
         # Process the line.  The nop backend handles disabled lines.
-        disable=${str%%disable *}
+        disable="0"
+        if has_property "$str" "disable"; then
+            disable="1"
+        fi
         echo
-        if test -z "$disable"; then
+        if [ "$disable" = "1" ]; then
             # Pass the disabled state as an arg for the simple
             # or DTrace backends which handle it dynamically.
             # For all other backends, call lineto$1_nop()
-- 
cgit v1.2.3-55-g7522


From dd215f646c72b4cf680097b13aeb8b0c589dceb2 Mon Sep 17 00:00:00 2001
From: Lluís
Date: Wed, 31 Aug 2011 20:31:38 +0200
Subject: trace: always use the "nop" backend on events with the "disable"
 keyword

Any event with the keyword/property "disable" generates an empty trace event
using the "nop" backend, regardless of the current backend.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 docs/tracing.txt  | 25 +++++++++++++++----------
 scripts/tracetool | 15 ++-------------
 2 files changed, 17 insertions(+), 23 deletions(-)

(limited to 'scripts')

diff --git a/docs/tracing.txt b/docs/tracing.txt
index 455da37969..85793cf173 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -12,15 +12,11 @@ for debugging, profiling, and observing execution.
     ./configure --trace-backend=simple
     make
 
-2. Enable trace events you are interested in:
-
-    $EDITOR trace-events  # remove "disable" from events you want
-
-3. Run the virtual machine to produce a trace file:
+2. Run the virtual machine to produce a trace file:
 
     qemu ... # your normal QEMU invocation
 
-4. Pretty-print the binary trace file:
+3. Pretty-print the binary trace file:
 
     ./simpletrace.py trace-events trace-*
 
@@ -103,10 +99,11 @@ portability macros, ensure they are preceded and followed by double quotes:
 4. Name trace events after their function.  If there are multiple trace events
    in one function, append a unique distinguisher at the end of the name.
 
-5. Declare trace events with the "disable" property.  Some trace events can
-   produce a lot of output and users are typically only interested in a subset
-   of trace events.  Marking trace events disabled by default saves the user
-   from having to manually disable noisy trace events.
+5. If specific trace events are going to be called a huge number of times, this
+   might have a noticeable performance impact even when the trace events are
+   programmatically disabled. In this case you should declare the trace event
+   with the "disable" property, which will effectively disable it at compile
+   time (using the "nop" backend).
 
 == Generic interface and monitor commands ==
 
@@ -165,6 +162,9 @@ The "nop" backend generates empty trace event functions so that the compiler
 can optimize out trace events completely.  This is the default and imposes no
 performance penalty.
 
+Note that regardless of the selected trace backend, events with the "disable"
+property will be generated with the "nop" backend.
+
 === Stderr ===
 
 The "stderr" backend sends trace events directly to standard error.  This
@@ -173,6 +173,11 @@ effectively turns trace events into debug printfs.
 This is the simplest backend and can be used together with existing code that
 uses DPRINTF().
 
+Note that with this backend trace events cannot be programmatically
+enabled/disabled. Thus, in order to trim down the amount of output and the
+performance impact of tracing, you might want to add the "disable" property in
+the "trace-events" file for those events you are not interested in.
+
 === Simpletrace ===
 
 The "simple" backend supports common use cases and comes as part of the QEMU
diff --git a/scripts/tracetool b/scripts/tracetool
index e649a5b807..e2cf11784b 100755
--- a/scripts/tracetool
+++ b/scripts/tracetool
@@ -506,21 +506,10 @@ convert()
         # Skip comments and empty lines
         test -z "${str%%#*}" && continue
 
+        echo
         # Process the line.  The nop backend handles disabled lines.
-        disable="0"
         if has_property "$str" "disable"; then
-            disable="1"
-        fi
-        echo
-        if [ "$disable" = "1" ]; then
-            # Pass the disabled state as an arg for the simple
-            # or DTrace backends which handle it dynamically.
-            # For all other backends, call lineto$1_nop()
-            if [ $backend = "simple" -o "$backend" = "dtrace" ]; then
-                "$process_line" "$str"
-            else
-                "lineto$1_nop" "${str##disable }"
-            fi
+            "lineto$1_nop" "$str"
         else
             "$process_line" "$str"
         fi
-- 
cgit v1.2.3-55-g7522


From 03727e6a06087dc8f46d5674b4b29262bf7377a4 Mon Sep 17 00:00:00 2001
From: Lluís
Date: Wed, 31 Aug 2011 20:31:45 +0200
Subject: trace: [simple] disable all trace points by default

Note that this refers to the backend-specific state (whether the output must be
generated), not the event "disabled" property (which always uses the "nop"
backend).

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 docs/tracing.txt  | 11 ++++++++---
 scripts/tracetool |  9 ++-------
 trace-events      |  3 ---
 3 files changed, 10 insertions(+), 13 deletions(-)

(limited to 'scripts')

diff --git a/docs/tracing.txt b/docs/tracing.txt
index 85793cf173..d1d4e8cba2 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -12,11 +12,16 @@ for debugging, profiling, and observing execution.
     ./configure --trace-backend=simple
     make
 
-2. Run the virtual machine to produce a trace file:
+2. Create a file with the events you want to trace:
 
-    qemu ... # your normal QEMU invocation
+   echo bdrv_aio_readv   > /tmp/events
+   echo bdrv_aio_writev >> /tmp/events
 
-3. Pretty-print the binary trace file:
+3. Run the virtual machine to produce a trace file:
+
+    qemu -trace events=/tmp/events ... # your normal QEMU invocation
+
+4. Pretty-print the binary trace file:
 
     ./simpletrace.py trace-events trace-*
 
diff --git a/scripts/tracetool b/scripts/tracetool
index e2cf11784b..c740080ebb 100755
--- a/scripts/tracetool
+++ b/scripts/tracetool
@@ -221,15 +221,10 @@ EOF
 
 linetoc_simple()
 {
-    local name state
+    local name
     name=$(get_name "$1")
-    if has_property "$1" "disable"; then
-        state="0"
-    else
-        state="1"
-    fi
     cat <<EOF
-{.tp_name = "$name", .state=$state},
+{.tp_name = "$name", .state=0},
 EOF
     simple_event_num=$((simple_event_num + 1))
 }
diff --git a/trace-events b/trace-events
index f08d6d0b41..eb612e83d1 100644
--- a/trace-events
+++ b/trace-events
@@ -17,9 +17,6 @@
 # Example: qemu_malloc(size_t size) "size %zu"
 #
 # The "disable" keyword will build without the trace event.
-# In case of 'simple' trace backend, it will allow the trace event to be
-# compiled, but this would be turned off by default. It can be toggled on via
-# the monitor.
 #
 # The <name> must be a valid as a C function name.
 #
-- 
cgit v1.2.3-55-g7522


From 9a82b6a590bd7c845ab9754b34b33ffee982ccb2 Mon Sep 17 00:00:00 2001
From: Lluís
Date: Wed, 31 Aug 2011 20:31:51 +0200
Subject: trace: [stderr] add support for dynamically enabling/disabling events

Uses the generic interface provided in "trace/control.h" in order to provide
a programmatic interface as well as command line and monitor controls.

Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 Makefile.objs     |  2 ++
 configure         |  1 +
 docs/tracing.txt  |  5 -----
 qemu-options.hx   |  3 ++-
 scripts/tracetool | 33 ++++++++++++++++++++++++++++-----
 trace/stderr.c    | 37 +++++++++++++++++++++++++++++++++++++
 trace/stderr.h    | 11 +++++++++++
 7 files changed, 81 insertions(+), 11 deletions(-)
 create mode 100644 trace/stderr.c
 create mode 100644 trace/stderr.h

(limited to 'scripts')

diff --git a/Makefile.objs b/Makefile.objs
index 036a4eb6ab..26b885bfeb 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -384,6 +384,8 @@ trace-nested-$(CONFIG_TRACE_DEFAULT) += default.o
 trace-nested-$(CONFIG_TRACE_SIMPLE) += simple.o
 trace-obj-$(CONFIG_TRACE_SIMPLE) += qemu-timer-common.o
 
+trace-nested-$(CONFIG_TRACE_STDERR) += stderr.o
+
 trace-nested-y += control.o
 
 trace-obj-y += $(addprefix trace/, $(trace-nested-y))
diff --git a/configure b/configure
index 4f9b27ced4..300d34bd32 100755
--- a/configure
+++ b/configure
@@ -3078,6 +3078,7 @@ if test "$trace_backend" = "simple"; then
 fi
 if test "$trace_backend" = "stderr"; then
   echo "CONFIG_TRACE_STDERR=y" >> $config_host_mak
+  trace_default=no
 fi
 if test "$trace_backend" = "ust"; then
   echo "CONFIG_TRACE_UST=y" >> $config_host_mak
diff --git a/docs/tracing.txt b/docs/tracing.txt
index d1d4e8cba2..4b27ab0c2a 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -178,11 +178,6 @@ effectively turns trace events into debug printfs.
 This is the simplest backend and can be used together with existing code that
 uses DPRINTF().
 
-Note that with this backend trace events cannot be programmatically
-enabled/disabled. Thus, in order to trim down the amount of output and the
-performance impact of tracing, you might want to add the "disable" property in
-the "trace-events" file for those events you are not interested in.
-
 === Simpletrace ===
 
 The "simple" backend supports common use cases and comes as part of the QEMU
diff --git a/qemu-options.hx b/qemu-options.hx
index edd181bb8e..f672365e42 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2454,7 +2454,8 @@ Immediately enable events listed in @var{file}.
 The file must contain one event name (as listed in the @var{trace-events} file)
 per line.
 
-This option is only available when using the @var{simple} tracing backend.
+This option is only available when using the @var{simple} and @var{stderr}
+tracing backends.
 @item file=@var{file}
 Log output traces to @var{file}.
 
diff --git a/scripts/tracetool b/scripts/tracetool
index c740080ebb..743d246289 100755
--- a/scripts/tracetool
+++ b/scripts/tracetool
@@ -241,7 +241,12 @@ linetoh_begin_stderr()
 {
     cat <<EOF
 #include <stdio.h>
+#include "trace/stderr.h"
+
+extern TraceEvent trace_list[];
 EOF
+
+    stderr_event_num=0
 }
 
 linetoh_stderr()
@@ -260,29 +265,47 @@ linetoh_stderr()
     cat <<EOF
 static inline void trace_$name($args)
 {
-    fprintf(stderr, "$name $fmt\n" $argnames);
+    if (trace_list[$stderr_event_num].state != 0) {
+        fprintf(stderr, "$name $fmt\n" $argnames);
+    }
 }
 EOF
+    stderr_event_num=$((stderr_event_num + 1))
+
 }
 
 linetoh_end_stderr()
 {
-return
+    cat <<EOF
+#define NR_TRACE_EVENTS $stderr_event_num
+EOF
 }
 
 linetoc_begin_stderr()
 {
-return
+    cat <<EOF
+#include "trace.h"
+
+TraceEvent trace_list[] = {
+EOF
+    stderr_event_num=0
 }
 
 linetoc_stderr()
 {
-return
+    local name
+    name=$(get_name "$1")
+    cat <<EOF
+{.tp_name = "$name", .state=0},
+EOF
+    stderr_event_num=$(($stderr_event_num + 1))
 }
 
 linetoc_end_stderr()
 {
-return
+    cat <<EOF
+};
+EOF
 }
 #END OF STDERR
 
diff --git a/trace/stderr.c b/trace/stderr.c
new file mode 100644
index 0000000000..7107c4a131
--- /dev/null
+++ b/trace/stderr.c
@@ -0,0 +1,37 @@
+#include "trace.h"
+#include "trace/control.h"
+
+
+void trace_print_events(FILE *stream, fprintf_function stream_printf)
+{
+    unsigned int i;
+
+    for (i = 0; i < NR_TRACE_EVENTS; i++) {
+        stream_printf(stream, "%s [Event ID %u] : state %u\n",
+                      trace_list[i].tp_name, i, trace_list[i].state);
+    }
+}
+
+bool trace_event_set_state(const char *name, bool state)
+{
+    unsigned int i;
+
+    for (i = 0; i < NR_TRACE_EVENTS; i++) {
+        if (!strcmp(trace_list[i].tp_name, name)) {
+            trace_list[i].state = state;
+            return true;
+        }
+    }
+    return false;
+}
+
+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;
+}
diff --git a/trace/stderr.h b/trace/stderr.h
new file mode 100644
index 0000000000..d575b613e3
--- /dev/null
+++ b/trace/stderr.h
@@ -0,0 +1,11 @@
+#ifndef TRACE_STDERR_H
+#define TRACE_STDERR_H
+
+typedef uint64_t TraceEventID;
+
+typedef struct {
+    const char *tp_name;
+    bool state;
+} TraceEvent;
+
+#endif /* ! TRACE_STDERR_H */
-- 
cgit v1.2.3-55-g7522


From d8e8ef4ee05bfee0df84e2665d9196c4a954c095 Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi
Date: Thu, 25 Aug 2011 18:03:49 +0100
Subject: simpletrace: fix process() argument count

The simpletrace.process() function invokes analyzer methods with the
wrong number of arguments if a timestamp should be included.  This patch
fixes the issue so that trace analysis scripts can make use of
timestamps.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 scripts/simpletrace.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'scripts')

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 2ad56998ee..f55e5e63f9 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -102,10 +102,10 @@ def process(events, log, analyzer):
         fn_argcount = len(inspect.getargspec(fn)[0]) - 1
         if fn_argcount == event_argcount + 1:
             # Include timestamp as first argument
-            return lambda _, rec: fn(*rec[1:2 + fn_argcount])
+            return lambda _, rec: fn(*rec[1:2 + event_argcount])
         else:
             # Just arguments, no timestamp
-            return lambda _, rec: fn(*rec[2:2 + fn_argcount])
+            return lambda _, rec: fn(*rec[2:2 + event_argcount])
 
     analyzer.begin()
     fn_cache = {}
-- 
cgit v1.2.3-55-g7522