2 # SPDX-License-Identifier: GPL-2.0-only
3 # -*- coding: utf-8 -*-
5 """ This utility can be used to debug and tune the performance of the
6 intel_pstate driver. This utility can be used in two ways:
7 - If there is Linux trace file with pstate_sample events enabled, then
8 this utility can parse the trace file and generate performance plots.
9 - If user has not specified a trace file as input via command line parameters,
10 then this utility enables and collects trace data for a user specified interval
11 and generates performance plots.
14 Python version 2.7.x or higher
16 gnuplot-py 1.8 or higher
17 (Most of the distributions have these required packages. They may be called
18 gnuplot-py, phython-gnuplot or phython3-gnuplot, gnuplot-nox, ... )
20 HWP (Hardware P-States are disabled)
21 Kernel config for Linux trace is enabled
23 see print_help(): for Usage and Output details
26 from __future__
import print_function
27 from datetime
import datetime
39 __author__
= "Srinivas Pandruvada"
40 __copyright__
= " Copyright (c) 2017, Intel Corporation. "
41 __license__
= "GPL version 2"
46 # Define the csv file columns
66 global sample_num
, last_sec_cpu
, last_usec_cpu
, start_time
, testname
68 # 11 digits covers uptime to 115 days
69 getcontext().prec
= 11
72 last_sec_cpu
= [0] * MAX_CPUS
73 last_usec_cpu
= [0] * MAX_CPUS
76 print('intel_pstate_tracer.py:')
78 print(' If the trace file is available, then to simply parse and plot, use (sudo not required):')
79 print(' ./intel_pstate_tracer.py [-c cpus] -t <trace_file> -n <test_name>')
81 print(' ./intel_pstate_tracer.py [--cpu cpus] ---trace_file <trace_file> --name <test_name>')
82 print(' To generate trace file, parse and plot, use (sudo required):')
83 print(' sudo ./intel_pstate_tracer.py [-c cpus] -i <interval> -n <test_name> -m <kbytes>')
85 print(' sudo ./intel_pstate_tracer.py [--cpu cpus] --interval <interval> --name <test_name> --memory <kbytes>')
86 print(' Optional argument:')
87 print(' cpus: comma separated list of CPUs')
88 print(' kbytes: Kilo bytes of memory per CPU to allocate to the trace buffer. Default: 10240')
90 print(' If not already present, creates a "results/test_name" folder in the current working directory with:')
91 print(' cpu.csv - comma seperated values file with trace contents and some additional calculations.')
92 print(' cpu???.csv - comma seperated values file for CPU number ???.')
93 print(' *.png - a variety of PNG format plot files created from the trace contents and the additional calculations.')
95 print(' Avoid the use of _ (underscore) in test names, because in gnuplot it is a subscript directive.')
96 print(' Maximum number of CPUs is {0:d}. If there are more the script will abort with an error.'.format(MAX_CPUS
))
97 print(' Off-line CPUs cause the script to list some warnings, and create some empty files. Use the CPU mask feature for a clean run.')
98 print(' Empty y range warnings for autoscaled plots can occur and can be ignored.')
100 def plot_perf_busy_with_sample(cpu_index
):
101 """ Plot method to per cpu information """
103 file_name
= 'cpu{:0>3}.csv'.format(cpu_index
)
104 if os
.path
.exists(file_name
):
105 output_png
= "cpu%03d_perf_busy_vs_samples.png" % cpu_index
106 g_plot
= common_all_gnuplot_settings(output_png
)
107 # autoscale this one, no set y1 range
108 g_plot('set y2range [0:200]')
109 g_plot('set y2tics 0, 10')
110 g_plot('set title "{} : cpu perf busy vs. sample : CPU {:0>3} : {:%F %H:%M}"'.format(testname
, cpu_index
, datetime
.now()))
112 g_plot('set xlabel "Samples"')
113 g_plot('set ylabel "P-State"')
114 g_plot('set y2label "Scaled Busy/performance/io-busy(%)"')
115 set_4_plot_linestyles(g_plot
)
116 g_plot('plot "' + file_name
+ '" using {:d}:{:d} with linespoints linestyle 1 axis x1y2 title "performance",\\'.format(C_SAMPLE
, C_CORE
))
117 g_plot('"' + file_name
+ '" using {:d}:{:d} with linespoints linestyle 2 axis x1y2 title "scaled-busy",\\'.format(C_SAMPLE
, C_SCALED
))
118 g_plot('"' + file_name
+ '" using {:d}:{:d} with linespoints linestyle 3 axis x1y2 title "io-boost",\\'.format(C_SAMPLE
, C_BOOST
))
119 g_plot('"' + file_name
+ '" using {:d}:{:d} with linespoints linestyle 4 axis x1y1 title "P-State"'.format(C_SAMPLE
, C_TO
))
121 def plot_perf_busy(cpu_index
):
122 """ Plot some per cpu information """
124 file_name
= 'cpu{:0>3}.csv'.format(cpu_index
)
125 if os
.path
.exists(file_name
):
126 output_png
= "cpu%03d_perf_busy.png" % cpu_index
127 g_plot
= common_all_gnuplot_settings(output_png
)
128 # autoscale this one, no set y1 range
129 g_plot('set y2range [0:200]')
130 g_plot('set y2tics 0, 10')
131 g_plot('set title "{} : perf busy : CPU {:0>3} : {:%F %H:%M}"'.format(testname
, cpu_index
, datetime
.now()))
132 g_plot('set ylabel "P-State"')
133 g_plot('set y2label "Scaled Busy/performance/io-busy(%)"')
134 set_4_plot_linestyles(g_plot
)
135 g_plot('plot "' + file_name
+ '" using {:d}:{:d} with linespoints linestyle 1 axis x1y2 title "performance",\\'.format(C_ELAPSED
, C_CORE
))
136 g_plot('"' + file_name
+ '" using {:d}:{:d} with linespoints linestyle 2 axis x1y2 title "scaled-busy",\\'.format(C_ELAPSED
, C_SCALED
))
137 g_plot('"' + file_name
+ '" using {:d}:{:d} with linespoints linestyle 3 axis x1y2 title "io-boost",\\'.format(C_ELAPSED
, C_BOOST
))
138 g_plot('"' + file_name
+ '" using {:d}:{:d} with linespoints linestyle 4 axis x1y1 title "P-State"'.format(C_ELAPSED
, C_TO
))
140 def plot_durations(cpu_index
):
141 """ Plot per cpu durations """
143 file_name
= 'cpu{:0>3}.csv'.format(cpu_index
)
144 if os
.path
.exists(file_name
):
145 output_png
= "cpu%03d_durations.png" % cpu_index
146 g_plot
= common_all_gnuplot_settings(output_png
)
147 # autoscale this one, no set y range
148 g_plot('set title "{} : durations : CPU {:0>3} : {:%F %H:%M}"'.format(testname
, cpu_index
, datetime
.now()))
149 g_plot('set ylabel "Timer Duration (MilliSeconds)"')
151 g_plot('set key off')
152 set_4_plot_linestyles(g_plot
)
153 g_plot('plot "' + file_name
+ '" using {:d}:{:d} with linespoints linestyle 1 axis x1y1'.format(C_ELAPSED
, C_DURATION
))
155 def plot_loads(cpu_index
):
156 """ Plot per cpu loads """
158 file_name
= 'cpu{:0>3}.csv'.format(cpu_index
)
159 if os
.path
.exists(file_name
):
160 output_png
= "cpu%03d_loads.png" % cpu_index
161 g_plot
= common_all_gnuplot_settings(output_png
)
162 g_plot('set yrange [0:100]')
163 g_plot('set ytics 0, 10')
164 g_plot('set title "{} : loads : CPU {:0>3} : {:%F %H:%M}"'.format(testname
, cpu_index
, datetime
.now()))
165 g_plot('set ylabel "CPU load (percent)"')
167 g_plot('set key off')
168 set_4_plot_linestyles(g_plot
)
169 g_plot('plot "' + file_name
+ '" using {:d}:{:d} with linespoints linestyle 1 axis x1y1'.format(C_ELAPSED
, C_LOAD
))
171 def plot_pstate_cpu_with_sample():
172 """ Plot all cpu information """
174 if os
.path
.exists('cpu.csv'):
175 output_png
= 'all_cpu_pstates_vs_samples.png'
176 g_plot
= common_all_gnuplot_settings(output_png
)
177 # autoscale this one, no set y range
179 g_plot('set xlabel "Samples"')
180 g_plot('set ylabel "P-State"')
181 g_plot('set title "{} : cpu pstate vs. sample : {:%F %H:%M}"'.format(testname
, datetime
.now()))
182 title_list
= subprocess
.check_output('ls cpu???.csv | sed -e \'s/.csv//\'',shell
=True).decode('utf-8').replace('\n', ' ')
183 plot_str
= "plot for [i in title_list] i.'.csv' using {:d}:{:d} pt 7 ps 1 title i".format(C_SAMPLE
, C_TO
)
184 g_plot('title_list = "{}"'.format(title_list
))
187 def plot_pstate_cpu():
188 """ Plot all cpu information from csv files """
190 output_png
= 'all_cpu_pstates.png'
191 g_plot
= common_all_gnuplot_settings(output_png
)
192 # autoscale this one, no set y range
193 g_plot('set ylabel "P-State"')
194 g_plot('set title "{} : cpu pstates : {:%F %H:%M}"'.format(testname
, datetime
.now()))
196 # the following command is really cool, but doesn't work with the CPU masking option because it aborts on the first missing file.
197 # plot_str = 'plot for [i=0:*] file=sprintf("cpu%03d.csv",i) title_s=sprintf("cpu%03d",i) file using 16:7 pt 7 ps 1 title title_s'
199 title_list
= subprocess
.check_output('ls cpu???.csv | sed -e \'s/.csv//\'',shell
=True).decode('utf-8').replace('\n', ' ')
200 plot_str
= "plot for [i in title_list] i.'.csv' using {:d}:{:d} pt 7 ps 1 title i".format(C_ELAPSED
, C_TO
)
201 g_plot('title_list = "{}"'.format(title_list
))
205 """ Plot all cpu loads """
207 output_png
= 'all_cpu_loads.png'
208 g_plot
= common_all_gnuplot_settings(output_png
)
209 g_plot('set yrange [0:100]')
210 g_plot('set ylabel "CPU load (percent)"')
211 g_plot('set title "{} : cpu loads : {:%F %H:%M}"'.format(testname
, datetime
.now()))
213 title_list
= subprocess
.check_output('ls cpu???.csv | sed -e \'s/.csv//\'',shell
=True).decode('utf-8').replace('\n', ' ')
214 plot_str
= "plot for [i in title_list] i.'.csv' using {:d}:{:d} pt 7 ps 1 title i".format(C_ELAPSED
, C_LOAD
)
215 g_plot('title_list = "{}"'.format(title_list
))
218 def plot_frequency_cpu():
219 """ Plot all cpu frequencies """
221 output_png
= 'all_cpu_frequencies.png'
222 g_plot
= common_all_gnuplot_settings(output_png
)
223 # autoscale this one, no set y range
224 g_plot('set ylabel "CPU Frequency (GHz)"')
225 g_plot('set title "{} : cpu frequencies : {:%F %H:%M}"'.format(testname
, datetime
.now()))
227 title_list
= subprocess
.check_output('ls cpu???.csv | sed -e \'s/.csv//\'',shell
=True).decode('utf-8').replace('\n', ' ')
228 plot_str
= "plot for [i in title_list] i.'.csv' using {:d}:{:d} pt 7 ps 1 title i".format(C_ELAPSED
, C_FREQ
)
229 g_plot('title_list = "{}"'.format(title_list
))
232 def plot_duration_cpu():
233 """ Plot all cpu durations """
235 output_png
= 'all_cpu_durations.png'
236 g_plot
= common_all_gnuplot_settings(output_png
)
237 # autoscale this one, no set y range
238 g_plot('set ylabel "Timer Duration (MilliSeconds)"')
239 g_plot('set title "{} : cpu durations : {:%F %H:%M}"'.format(testname
, datetime
.now()))
241 title_list
= subprocess
.check_output('ls cpu???.csv | sed -e \'s/.csv//\'',shell
=True).decode('utf-8').replace('\n', ' ')
242 plot_str
= "plot for [i in title_list] i.'.csv' using {:d}:{:d} pt 7 ps 1 title i".format(C_ELAPSED
, C_DURATION
)
243 g_plot('title_list = "{}"'.format(title_list
))
246 def plot_scaled_cpu():
247 """ Plot all cpu scaled busy """
249 output_png
= 'all_cpu_scaled.png'
250 g_plot
= common_all_gnuplot_settings(output_png
)
251 # autoscale this one, no set y range
252 g_plot('set ylabel "Scaled Busy (Unitless)"')
253 g_plot('set title "{} : cpu scaled busy : {:%F %H:%M}"'.format(testname
, datetime
.now()))
255 title_list
= subprocess
.check_output('ls cpu???.csv | sed -e \'s/.csv//\'',shell
=True).decode('utf-8').replace('\n', ' ')
256 plot_str
= "plot for [i in title_list] i.'.csv' using {:d}:{:d} pt 7 ps 1 title i".format(C_ELAPSED
, C_SCALED
)
257 g_plot('title_list = "{}"'.format(title_list
))
260 def plot_boost_cpu():
261 """ Plot all cpu IO Boosts """
263 output_png
= 'all_cpu_boost.png'
264 g_plot
= common_all_gnuplot_settings(output_png
)
265 g_plot('set yrange [0:100]')
266 g_plot('set ylabel "CPU IO Boost (percent)"')
267 g_plot('set title "{} : cpu io boost : {:%F %H:%M}"'.format(testname
, datetime
.now()))
269 title_list
= subprocess
.check_output('ls cpu???.csv | sed -e \'s/.csv//\'',shell
=True).decode('utf-8').replace('\n', ' ')
270 plot_str
= "plot for [i in title_list] i.'.csv' using {:d}:{:d} pt 7 ps 1 title i".format(C_ELAPSED
, C_BOOST
)
271 g_plot('title_list = "{}"'.format(title_list
))
275 """ Plot all cpu tsc ghz """
277 output_png
= 'all_cpu_ghz.png'
278 g_plot
= common_all_gnuplot_settings(output_png
)
279 # autoscale this one, no set y range
280 g_plot('set ylabel "TSC Frequency (GHz)"')
281 g_plot('set title "{} : cpu TSC Frequencies (Sanity check calculation) : {:%F %H:%M}"'.format(testname
, datetime
.now()))
283 title_list
= subprocess
.check_output('ls cpu???.csv | sed -e \'s/.csv//\'',shell
=True).decode('utf-8').replace('\n', ' ')
284 plot_str
= "plot for [i in title_list] i.'.csv' using {:d}:{:d} pt 7 ps 1 title i".format(C_ELAPSED
, C_GHZ
)
285 g_plot('title_list = "{}"'.format(title_list
))
288 def common_all_gnuplot_settings(output_png
):
289 """ common gnuplot settings for multiple CPUs one one graph. """
291 g_plot
= common_gnuplot_settings()
292 g_plot('set output "' + output_png
+ '"')
295 def common_gnuplot_settings():
296 """ common gnuplot settings. """
298 g_plot
= Gnuplot
.Gnuplot(persist
=1)
299 # The following line is for rigor only. It seems to be assumed for .csv files
300 g_plot('set datafile separator \",\"')
301 g_plot('set ytics nomirror')
302 g_plot('set xtics nomirror')
303 g_plot('set xtics font ", 10"')
304 g_plot('set ytics font ", 10"')
305 g_plot('set tics out scale 1.0')
307 g_plot('set key out horiz')
308 g_plot('set key bot center')
309 g_plot('set key samplen 2 spacing .8 font ", 9"')
310 g_plot('set term png size 1200, 600')
311 g_plot('set title font ", 11"')
312 g_plot('set ylabel font ", 10"')
313 g_plot('set xlabel font ", 10"')
314 g_plot('set xlabel offset 0, 0.5')
315 g_plot('set xlabel "Elapsed Time (Seconds)"')
318 def set_4_plot_linestyles(g_plot
):
319 """ set the linestyles used for 4 plots in 1 graphs. """
321 g_plot('set style line 1 linetype 1 linecolor rgb "green" pointtype -1')
322 g_plot('set style line 2 linetype 1 linecolor rgb "red" pointtype -1')
323 g_plot('set style line 3 linetype 1 linecolor rgb "purple" pointtype -1')
324 g_plot('set style line 4 linetype 1 linecolor rgb "blue" pointtype -1')
326 def store_csv(cpu_int
, time_pre_dec
, time_post_dec
, core_busy
, scaled
, _from
, _to
, mperf
, aperf
, tsc
, freq_ghz
, io_boost
, common_comm
, load
, duration_ms
, sample_num
, elapsed_time
, tsc_ghz
):
327 """ Store master csv file information """
329 global graph_data_present
331 if cpu_mask
[cpu_int
] == 0:
335 f_handle
= open('cpu.csv', 'a')
336 string_buffer
= "CPU_%03u, %05u, %06u, %u, %u, %u, %u, %u, %u, %u, %.4f, %u, %.2f, %.3f, %u, %.3f, %.3f, %s\n" % (cpu_int
, int(time_pre_dec
), int(time_post_dec
), int(core_busy
), int(scaled
), int(_from
), int(_to
), int(mperf
), int(aperf
), int(tsc
), freq_ghz
, int(io_boost
), load
, duration_ms
, sample_num
, elapsed_time
, tsc_ghz
, common_comm
)
337 f_handle
.write(string_buffer
);
340 print('IO error cpu.csv')
343 graph_data_present
= True;
346 """ seperate the all csv file into per CPU csv files. """
348 global current_max_cpu
350 if os
.path
.exists('cpu.csv'):
351 for index
in range(0, current_max_cpu
+ 1):
352 if cpu_mask
[int(index
)] != 0:
353 os
.system('grep -m 1 common_cpu cpu.csv > cpu{:0>3}.csv'.format(index
))
354 os
.system('grep CPU_{:0>3} cpu.csv >> cpu{:0>3}.csv'.format(index
, index
))
356 def fix_ownership(path
):
357 """Change the owner of the file to SUDO_UID, if required"""
359 uid
= os
.environ
.get('SUDO_UID')
360 gid
= os
.environ
.get('SUDO_GID')
362 os
.chown(path
, int(uid
), int(gid
))
364 def cleanup_data_files():
365 """ clean up existing data files """
367 if os
.path
.exists('cpu.csv'):
369 f_handle
= open('cpu.csv', 'a')
370 f_handle
.write('common_cpu, common_secs, common_usecs, core_busy, scaled_busy, from, to, mperf, aperf, tsc, freq, boost, load, duration_ms, sample_num, elapsed_time, tsc_ghz, common_comm')
374 def clear_trace_file():
375 """ Clear trace file """
378 f_handle
= open('/sys/kernel/debug/tracing/trace', 'w')
381 print('IO error clearing trace file ')
388 open('/sys/kernel/debug/tracing/events/power/pstate_sample/enable'
391 print('IO error enabling trace ')
395 """ Disable trace """
398 open('/sys/kernel/debug/tracing/events/power/pstate_sample/enable'
401 print('IO error disabling trace ')
404 def set_trace_buffer_size():
405 """ Set trace buffer size """
408 with
open('/sys/kernel/debug/tracing/buffer_size_kb', 'w') as fp
:
411 print('IO error setting trace buffer size ')
414 def free_trace_buffer():
415 """ Free the trace buffer memory """
418 open('/sys/kernel/debug/tracing/buffer_size_kb'
421 print('IO error freeing trace buffer ')
424 def read_trace_data(filename
):
425 """ Read and parse trace data """
427 global current_max_cpu
428 global sample_num
, last_sec_cpu
, last_usec_cpu
, start_time
431 data
= open(filename
, 'r').read()
433 print('Error opening ', filename
)
436 for line
in data
.splitlines():
438 re
.search(r
'(^(.*?)\[)((\d+)[^\]])(.*?)(\d+)([.])(\d+)(.*?core_busy=)(\d+)(.*?scaled=)(\d+)(.*?from=)(\d+)(.*?to=)(\d+)(.*?mperf=)(\d+)(.*?aperf=)(\d+)(.*?tsc=)(\d+)(.*?freq=)(\d+)'
442 cpu
= search_obj
.group(3)
446 time_pre_dec
= search_obj
.group(6)
447 time_post_dec
= search_obj
.group(8)
448 core_busy
= search_obj
.group(10)
449 scaled
= search_obj
.group(12)
450 _from
= search_obj
.group(14)
451 _to
= search_obj
.group(16)
452 mperf
= search_obj
.group(18)
453 aperf
= search_obj
.group(20)
454 tsc
= search_obj
.group(22)
455 freq
= search_obj
.group(24)
456 common_comm
= search_obj
.group(2).replace(' ', '')
458 # Not all kernel versions have io_boost field
460 search_obj
= re
.search(r
'.*?io_boost=(\d+)', line
)
462 io_boost
= search_obj
.group(1)
465 start_time
= Decimal(time_pre_dec
) + Decimal(time_post_dec
) / Decimal(1000000)
468 if last_sec_cpu
[cpu_int
] == 0 :
469 last_sec_cpu
[cpu_int
] = time_pre_dec
470 last_usec_cpu
[cpu_int
] = time_post_dec
472 duration_us
= (int(time_pre_dec
) - int(last_sec_cpu
[cpu_int
])) * 1000000 + (int(time_post_dec
) - int(last_usec_cpu
[cpu_int
]))
473 duration_ms
= Decimal(duration_us
) / Decimal(1000)
474 last_sec_cpu
[cpu_int
] = time_pre_dec
475 last_usec_cpu
[cpu_int
] = time_post_dec
476 elapsed_time
= Decimal(time_pre_dec
) + Decimal(time_post_dec
) / Decimal(1000000) - start_time
477 load
= Decimal(int(mperf
)*100)/ Decimal(tsc
)
478 freq_ghz
= Decimal(freq
)/Decimal(1000000)
479 # Sanity check calculation, typically anomalies indicate missed samples
480 # However, check for 0 (should never occur)
482 if duration_ms
!= Decimal(0) :
483 tsc_ghz
= Decimal(tsc
)/duration_ms
/Decimal(1000000)
484 store_csv(cpu_int
, time_pre_dec
, time_post_dec
, core_busy
, scaled
, _from
, _to
, mperf
, aperf
, tsc
, freq_ghz
, io_boost
, common_comm
, load
, duration_ms
, sample_num
, elapsed_time
, tsc_ghz
)
486 if cpu_int
> current_max_cpu
:
487 current_max_cpu
= cpu_int
488 # End of for each trace line loop
489 # Now seperate the main overall csv file into per CPU csv files.
492 def signal_handler(signal
, frame
):
493 print(' SIGINT: Forcing cleanup before exit.')
501 signal
.signal(signal
.SIGINT
, signal_handler
)
508 graph_data_present
= False;
513 cpu_mask
= zeros((MAX_CPUS
,), dtype
=int)
516 opts
, args
= getopt
.getopt(sys
.argv
[1:],"ht:i:c:n:m:",["help","trace_file=","interval=","cpu=","name=","memory="])
517 except getopt
.GetoptError
:
520 for opt
, arg
in opts
:
524 elif opt
in ("-t", "--trace_file"):
526 location
= os
.path
.realpath(os
.path
.join(os
.getcwd(), os
.path
.dirname(__file__
)))
527 filename
= os
.path
.join(location
, arg
)
528 elif opt
in ("-i", "--interval"):
531 elif opt
in ("-c", "--cpu"):
533 elif opt
in ("-n", "--name"):
536 elif opt
in ("-m", "--memory"):
539 if not (valid1
and valid2
):
544 for p
in re
.split("[,]", cpu_list
):
545 if int(p
) < MAX_CPUS
:
548 for i
in range (0, MAX_CPUS
):
551 if not os
.path
.exists('results'):
553 # The regular user needs to own the directory, not root.
554 fix_ownership('results')
557 if os
.path
.exists(testname
):
558 print('The test name directory already exists. Please provide a unique test name. Test re-run not supported, yet.')
561 # The regular user needs to own the directory, not root.
562 fix_ownership(testname
)
565 # Temporary (or perhaps not)
566 cur_version
= sys
.version_info
567 print('python version (should be >= 2.7):')
570 # Left as "cleanup" for potential future re-run ability.
574 filename
= "/sys/kernel/debug/tracing/trace"
576 set_trace_buffer_size()
578 print('Sleeping for ', interval
, 'seconds')
579 time
.sleep(int(interval
))
584 read_trace_data(filename
)
591 if graph_data_present
== False:
592 print('No valid data to plot')
595 for cpu_no
in range(0, current_max_cpu
+ 1):
596 plot_perf_busy_with_sample(cpu_no
)
597 plot_perf_busy(cpu_no
)
598 plot_durations(cpu_no
)
601 plot_pstate_cpu_with_sample()
610 # It is preferrable, but not necessary, that the regular user owns the files, not root.
611 for root
, dirs
, files
in os
.walk('.'):