perf scripting python: Add function to get a config value

This can be used to get config values like which objdump Perf uses for
disassembly.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Tested-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Ruidong Tian <tianruidong@linux.alibaba.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Benjamin Gray <bgray@linux.ibm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: coresight@lists.linaro.org
Cc: John Garry <john.g.garry@oracle.com>
Cc: scclevenger@os.amperecomputing.com
Link: https://lore.kernel.org/r/20240916135743.1490403-4-james.clark@linaro.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/Documentation/perf-script-python.txt b/tools/perf/Documentation/perf-script-python.txt
index 13e37e9385ee421fe89427420932f8f1f6d61d3f..27a1cac6fe7638639145bfc5ff3e49c194cf71d2 100644 (file)
--- a/tools/perf/Documentation/perf-script-python.txt
+++ b/tools/perf/Documentation/perf-script-python.txt
@@ -624,7 +624,7 @@ as perf_trace_context.perf_script_context .
  perf_set_itrace_options(context, itrace_options) - set --itrace options if they have not been set already
  perf_sample_srcline(context) - returns source_file_name, line_number
  perf_sample_srccode(context) - returns source_file_name, line_number, source_line
-
+ perf_config_get(config_name) - returns the value of the named config item, or None if unset
 
 Util.py Module
 ~~~~~~~~~~~~~~

diff --git a/tools/perf/scripts/python/Perf-Trace-Util/Context.c b/tools/perf/scripts/python/Perf-Trace-Util/Context.c
index 3954bd1587ce95defcc6191bc4f867c0c60b4e89..01f54d6724a5f83c7f6d30b3b0f228fa11e9bf3f 100644 (file)
--- a/tools/perf/scripts/python/Perf-Trace-Util/Context.c
+++ b/tools/perf/scripts/python/Perf-Trace-Util/Context.c
@@ -12,6 +12,7 @@
 #define PY_SSIZE_T_CLEAN
 
 #include <Python.h>
+#include "../../../util/config.h"
 #include "../../../util/trace-event.h"
 #include "../../../util/event.h"
 #include "../../../util/symbol.h"
@@ -182,6 +183,15 @@ static PyObject *perf_sample_srccode(PyObject *obj, PyObject *args)
        return perf_sample_src(obj, args, true);
 }
 
+static PyObject *__perf_config_get(PyObject *obj, PyObject *args)
+{
+       const char *config_name;
+
+       if (!PyArg_ParseTuple(args, "s", &config_name))
+               return NULL;
+       return Py_BuildValue("s", perf_config_get(config_name));
+}
+
 static PyMethodDef ContextMethods[] = {
 #ifdef HAVE_LIBTRACEEVENT
        { "common_pc", perf_trace_context_common_pc, METH_VARARGS,
@@ -199,6 +209,7 @@ static PyMethodDef ContextMethods[] = {
          METH_VARARGS, "Get source file name and line number."},
        { "perf_sample_srccode", perf_sample_srccode,
          METH_VARARGS, "Get source file name, line number and line."},
+       { "perf_config_get", __perf_config_get, METH_VARARGS, "Get perf config entry"},
        { NULL, NULL, 0, NULL}
 };
 

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 7a650de0db83f98fee6d44fc6689d0967722871c..68f9407ca74b9202732e8af66972187747ca27ac 100644 (file)
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -912,6 +912,7 @@ void set_buildid_dir(const char *dir)
 struct perf_config_scan_data {
        const char *name;
        const char *fmt;
+       const char *value;
        va_list args;
        int ret;
 };
@@ -939,3 +940,24 @@ int perf_config_scan(const char *name, const char *fmt, ...)
 
        return d.ret;
 }
+
+static int perf_config_get_cb(const char *var, const char *value, void *data)
+{
+       struct perf_config_scan_data *d = data;
+
+       if (!strcmp(var, d->name))
+               d->value = value;
+
+       return 0;
+}
+
+const char *perf_config_get(const char *name)
+{
+       struct perf_config_scan_data d = {
+               .name = name,
+               .value = NULL,
+       };
+
+       perf_config(perf_config_get_cb, &d);
+       return d.value;
+}

diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
index 2e5e808928a55a8bc8f9aeab7ae19e33df2a4aaf..9971313d61c1e5c6769a1a8dd0c75eab81d7af7c 100644 (file)
--- a/tools/perf/util/config.h
+++ b/tools/perf/util/config.h
@@ -30,6 +30,7 @@ typedef int (*config_fn_t)(const char *, const char *, void *);
 int perf_default_config(const char *, const char *, void *);
 int perf_config(config_fn_t fn, void *);
 int perf_config_scan(const char *name, const char *fmt, ...) __scanf(2, 3);
+const char *perf_config_get(const char *name);
 int perf_config_set(struct perf_config_set *set,
                    config_fn_t fn, void *data);
 int perf_config_int(int *dest, const char *, const char *);