From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
Add a set_affinity API that can let the user set what CPUs to enable
tracing on.
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
This depends on the new libtracefs API found here:
https://patchwork.kernel.org/project/linux-trace-devel/patch/20211217180450.12d3524b@xxxxxxxxxxxxxxxxxx/
This can be worked out later if you have comments. And I'll keep
the VMWare tag, as I did write while still working at VMware. I figured
that my last patch as a VMware employee would be my first patch
to trace-cruncher ;-)
examples/test-affinity.py | 5 ++++
src/ftracepy-utils.c | 58 +++++++++++++++++++++++++++++++++++++++
src/ftracepy-utils.h | 3 ++
src/ftracepy.c | 5 ++++
4 files changed, 71 insertions(+)
create mode 100755 examples/test-affinity.py
diff --git a/examples/test-affinity.py b/examples/test-affinity.py
new file mode 100755
index 0000000..1619931
--- /dev/null
+++ b/examples/test-affinity.py
@@ -0,0 +1,5 @@
+#!/usr/bin/env python3
+
+import tracecruncher.ftracepy as ft
+
+ft.set_affinity(cpus=["0-1","3"]);
diff --git a/src/ftracepy-utils.c b/src/ftracepy-utils.c
index a735d88..ab39cf1 100644
--- a/src/ftracepy-utils.c
+++ b/src/ftracepy-utils.c
@@ -2394,6 +2394,64 @@ PyObject *PyFtrace_hist(PyObject *self, PyObject *args,
return NULL;
}
+PyObject *PyFtrace_set_affinity(PyObject *self, PyObject *args,
+ PyObject *kwargs)
+{
+ struct tracefs_instance *instance;
+ static char *kwlist[] = {"cpus", "instance", NULL};
+ PyObject *py_cpus;
+ PyObject *py_inst = NULL;
+ const char *cpu_str;
+ struct trace_seq seq;
+ int ret;
+
+ if (!PyArg_ParseTupleAndKeywords(args,
+ kwargs,
+ "O|O",
+ kwlist,
+ &py_cpus,
+ &py_inst)) {
+ return NULL;
+ }
+
+ trace_seq_init(&seq);
+
+ if (PyUnicode_Check(py_cpus)) {
+ cpu_str = (const char *)PyUnicode_DATA(py_cpus);
+ if (trace_seq_puts(&seq, cpu_str) < 0)
+ goto err_seq;
+ } else if (PyList_CheckExact(py_cpus)) {
+ int i, n = PyList_Size(py_cpus);
+
+ for (i = 0; i < n; ++i) {
+ cpu_str = str_from_list(py_cpus, i);
+ if (i)
+ trace_seq_putc(&seq, ',');
+ if (trace_seq_puts(&seq, cpu_str) < 0)
+ goto err_seq;
+ }
+ }
+
+ if (!get_optional_instance(py_inst, &instance))
+ goto err;
+
+ trace_seq_terminate(&seq);
+ ret = tracefs_instance_set_affinity(instance, seq.buffer);
+ if (ret < 0) {
+ PyErr_SetString(TRACECRUNCHER_ERROR,
+ "Invalid \"cpus\" argument.");
+ goto err;
+ }
+
+ Py_RETURN_NONE;
+err_seq:
+ PyErr_SetString(TRACECRUNCHER_ERROR,
+ "Internal processing string error.");
+err:
+ trace_seq_destroy(&seq);
+ return NULL;
+}
+
PyObject *PyFtrace_set_ftrace_loglevel(PyObject *self, PyObject *args,
PyObject *kwargs)
{
diff --git a/src/ftracepy-utils.h b/src/ftracepy-utils.h
index d09c8bf..67f67ab 100644
--- a/src/ftracepy-utils.h
+++ b/src/ftracepy-utils.h
@@ -208,6 +208,9 @@ PyObject *PyFtrace_register_kretprobe(PyObject *self, PyObject *args,
PyObject *PyFtrace_hist(PyObject *self, PyObject *args,
PyObject *kwargs);
+PyObject *PyFtrace_set_affinity(PyObject *self, PyObject *args,
+ PyObject *kwargs);
+
PyObject *PyFtrace_set_ftrace_loglevel(PyObject *self, PyObject *args,
PyObject *kwargs);
diff --git a/src/ftracepy.c b/src/ftracepy.c
index b270b71..634f357 100644
--- a/src/ftracepy.c
+++ b/src/ftracepy.c
@@ -377,6 +377,11 @@ static PyMethodDef ftracepy_methods[] = {
METH_VARARGS | METH_KEYWORDS,
"Define a histogram."
},
+ {"set_affinity",
+ (PyCFunction) PyFtrace_set_affinity,
+ METH_VARARGS | METH_KEYWORDS,
+ "Find an existing ftrace instance."
+ },
{"set_ftrace_loglevel",
(PyCFunction) PyFtrace_set_ftrace_loglevel,
METH_VARARGS | METH_KEYWORDS,
--
2.31.1
|