diff options
Diffstat (limited to 'tools/tracing/rtla/sample')
-rw-r--r-- | tools/tracing/rtla/sample/timerlat_load.py | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/tools/tracing/rtla/sample/timerlat_load.py b/tools/tracing/rtla/sample/timerlat_load.py new file mode 100644 index 0000000000..8cc5eb2d2e --- /dev/null +++ b/tools/tracing/rtla/sample/timerlat_load.py @@ -0,0 +1,74 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0-only +# +# Copyright (C) 2024 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org> +# +# This is a sample code about how to use timerlat's timer by any workload +# so rtla can measure and provide auto-analysis for the overall latency (IOW +# the response time) for a task. +# +# Before running it, you need to dispatch timerlat with -U option in a terminal. +# Then # run this script pinned to a CPU on another terminal. For example: +# +# timerlat_load.py 1 -p 95 +# +# The "Timerlat IRQ" is the IRQ latency, The thread latency is the latency +# for the python process to get the CPU. The Ret from user Timer Latency is +# the overall latency. In other words, it is the response time for that +# activation. +# +# This is just an example, the load is reading 20MB of data from /dev/full +# It is in python because it is easy to read :-) + +import argparse +import sys +import os + +parser = argparse.ArgumentParser(description='user-space timerlat thread in Python') +parser.add_argument("cpu", help='CPU to run timerlat thread') +parser.add_argument("-p", "--prio", help='FIFO priority') + +args = parser.parse_args() + +try: + affinity_mask = { int(args.cpu) } +except: + print("Invalid cpu: " + args.cpu) + exit(1) + +try: + os.sched_setaffinity(0, affinity_mask); +except: + print("Error setting affinity") + exit(1) + +if (args.prio): + try: + param = os.sched_param(int(args.prio)) + os.sched_setscheduler(0, os.SCHED_FIFO, param) + except: + print("Error setting priority") + exit(1) + +try: + timerlat_path = "/sys/kernel/tracing/osnoise/per_cpu/cpu" + args.cpu + "/timerlat_fd" + timerlat_fd = open(timerlat_path, 'r') +except: + print("Error opening timerlat fd, did you run timerlat -U?") + exit(1) + +try: + data_fd = open("/dev/full", 'r'); +except: + print("Error opening data fd") + +while True: + try: + timerlat_fd.read(1) + data_fd.read(20*1024*1024) + except: + print("Leaving") + break + +timerlat_fd.close() +data_fd.close() |