From patchwork Tue Jan 18 01:12:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 12715772 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE3BDC433EF for ; Tue, 18 Jan 2022 01:12:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243960AbiARBMf (ORCPT ); Mon, 17 Jan 2022 20:12:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41488 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243926AbiARBMe (ORCPT ); Mon, 17 Jan 2022 20:12:34 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9AE44C061574 for ; Mon, 17 Jan 2022 17:12:34 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E755A6125B for ; Tue, 18 Jan 2022 01:12:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06940C36AEC; Tue, 18 Jan 2022 01:12:32 +0000 (UTC) Date: Mon, 17 Jan 2022 20:12:31 -0500 From: Steven Rostedt To: Linux Trace Devel Cc: Yordan Karadzhov Subject: [PATCH v2] trace-cruncher: Add API to set tracing CPU affinity Message-ID: <20220117201231.414a4799@gandalf.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org From: "Steven Rostedt (VMware)" Add a set_affinity API that can let the user set what CPUs to enable tracing on. Example: import tracecruncher.ftracepy as ft ft.set_affinity(cpus=["0-1","3"]); The above will set the top level instance affinity to 0,1,3 (or 0xb) To reset back to online CPUs: ft.reset_affinity() Where it will reset the top level instance back to all CPUS. Signed-off-by: Steven Rostedt (VMware) --- Changes since v1: https://lore.kernel.org/all/20211217182619.13db88f0@gandalf.local.home/ - Added reset_affinity() to set the instance to all CPUs Note, I did not add a get_affinity() because that requires adding a get_affinity to libtracefs() first. - Will now error if cpus is not PyUnicode or PyList. - Fixed up one line description of set affinity. examples/reset-affinity.py | 5 ++ examples/test-affinity.py | 5 ++ src/ftracepy-utils.c | 93 ++++++++++++++++++++++++++++++++++++++ src/ftracepy-utils.h | 6 +++ src/ftracepy.c | 10 ++++ 5 files changed, 119 insertions(+) create mode 100755 examples/reset-affinity.py create mode 100755 examples/test-affinity.py diff --git a/examples/reset-affinity.py b/examples/reset-affinity.py new file mode 100755 index 0000000..2bca32e --- /dev/null +++ b/examples/reset-affinity.py @@ -0,0 +1,5 @@ +#!/usr/bin/env python3 + +import tracecruncher.ftracepy as ft + +ft.reset_affinity(); 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..e42f69c 100644 --- a/src/ftracepy-utils.c +++ b/src/ftracepy-utils.c @@ -2394,6 +2394,99 @@ PyObject *PyFtrace_hist(PyObject *self, PyObject *args, return NULL; } +PyObject *PyFtrace_reset_affinity(PyObject *self, PyObject *args, + PyObject *kwargs) +{ + struct tracefs_instance *instance; + static char *kwlist[] = {"instance", NULL}; + PyObject *py_inst = NULL; + int ret; + + if (!PyArg_ParseTupleAndKeywords(args, + kwargs, + "|O", + kwlist, + &py_inst)) { + return NULL; + } + + if (!get_optional_instance(py_inst, &instance)) + goto err; + + /* NULL for CPUs will set all available CPUS */ + ret = tracefs_instance_set_affinity(instance, NULL); + if (ret < 0) { + PyErr_SetString(TRACECRUNCHER_ERROR, + "Failed to reset tracing affinity."); + goto err; + } + + Py_RETURN_NONE; +err: + 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; + int ret; + + if (!init_print_seq()) + return false; + + if (!PyArg_ParseTupleAndKeywords(args, + kwargs, + "O|O", + kwlist, + &py_cpus, + &py_inst)) { + return NULL; + } + + 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; + } + } else { + PyErr_SetString(TRACECRUNCHER_ERROR, + "Invalid \"cpus\" type."); + goto err; + } + + 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: + 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..4af557f 100644 --- a/src/ftracepy-utils.h +++ b/src/ftracepy-utils.h @@ -208,6 +208,12 @@ 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_reset_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..cd5d382 100644 --- a/src/ftracepy.c +++ b/src/ftracepy.c @@ -372,11 +372,21 @@ static PyMethodDef ftracepy_methods[] = { METH_VARARGS | METH_KEYWORDS, "Define a kretprobe." }, + {"reset_affinity", + (PyCFunction) PyFtrace_reset_affinity, + METH_VARARGS | METH_KEYWORDS, + "Set an instance tracing affinity to all CPUs" + }, {"hist", (PyCFunction) PyFtrace_hist, METH_VARARGS | METH_KEYWORDS, "Define a histogram." }, + {"set_affinity", + (PyCFunction) PyFtrace_set_affinity, + METH_VARARGS | METH_KEYWORDS, + "Return tracing affinity of an instance." + }, {"set_ftrace_loglevel", (PyCFunction) PyFtrace_set_ftrace_loglevel, METH_VARARGS | METH_KEYWORDS,