1 .. SPDX-License-Identifier: (GPL-2.0+ OR CC-BY-4.0)
3 ======================================================
4 Discovering Linux kernel subsystems used by a workload
5 ======================================================
7 :Authors: - Shuah Khan <skhan@linuxfoundation.org>
8 - Shefali Sharma <sshefali021@gmail.com>
9 :maintained-by: Shuah Khan <skhan@linuxfoundation.org>
14 * Understanding system resources necessary to build and run a workload
16 * Linux tracing and strace can be used to discover the system resources
17 in use by a workload. The completeness of the system usage information
18 depends on the completeness of coverage of a workload.
19 * Performance and security of the operating system can be analyzed with
20 the help of tools such as:
21 `perf <https://man7.org/linux/man-pages/man1/perf.1.html>`_,
22 `stress-ng <https://www.mankier.com/1/stress-ng>`_,
23 `paxtest <https://github.com/opntr/paxtest-freebsd>`_.
24 * Once we discover and understand the workload needs, we can focus on them
25 to avoid regressions and use it to evaluate safety considerations.
30 `strace <https://man7.org/linux/man-pages/man1/strace.1.html>`_ is a
31 diagnostic, instructional, and debugging tool and can be used to discover
32 the system resources in use by a workload. Once we discover and understand
33 the workload needs, we can focus on them to avoid regressions and use it
34 to evaluate safety considerations. We use strace tool to trace workloads.
36 This method of tracing using strace tells us the system calls invoked by
37 the workload and doesn't include all the system calls that can be invoked
38 by it. In addition, this tracing method tells us just the code paths within
39 these system calls that are invoked. As an example, if a workload opens a
40 file and reads from it successfully, then the success path is the one that
41 is traced. Any error paths in that system call will not be traced. If there
42 is a workload that provides full coverage of a workload then the method
43 outlined here will trace and find all possible code paths. The completeness
44 of the system usage information depends on the completeness of coverage of a
47 The goal is tracing a workload on a system running a default kernel without
48 requiring custom kernel installs.
50 How do we gather fine-grained system information?
51 =================================================
53 strace tool can be used to trace system calls made by a process and signals
54 it receives. System calls are the fundamental interface between an
55 application and the operating system kernel. They enable a program to
56 request services from the kernel. For instance, the open() system call in
57 Linux is used to provide access to a file in the file system. strace enables
58 us to track all the system calls made by an application. It lists all the
59 system calls made by a process and their resulting output.
61 You can generate profiling data combining strace and perf record tools to
62 record the events and information associated with a process. This provides
63 insight into the process. "perf annotate" tool generates the statistics of
64 each instruction of the program. This document goes over the details of how
65 to gather fine-grained information on a workload's usage of system resources.
67 We used strace to trace the perf, stress-ng, paxtest workloads to illustrate
68 our methodology to discover resources used by a workload. This process can
69 be applied to trace other workloads.
71 Getting the system ready for tracing
72 ====================================
74 Before we can get started we will show you how to get your system ready.
75 We assume that you have a Linux distribution running on a physical system
76 or a virtual machine. Most distributions will include strace command. Let’s
77 install other tools that aren’t usually included to build Linux kernel.
78 Please note that the following works on Debian based distributions. You
79 might have to find equivalent packages on other Linux distributions.
81 Install tools to build Linux kernel and tools in kernel repository.
82 scripts/ver_linux is a good way to check if your system already has
85 sudo apt-get build-essentials flex bison yacc
86 sudo apt install libelf-dev systemtap-sdt-dev libaudit-dev libslang2-dev libperl-dev libdw-dev
88 cscope is a good tool to browse kernel sources. Let's install it now::
90 sudo apt-get install cscope
92 Install stress-ng and paxtest::
94 apt-get install stress-ng
95 apt-get install paxtest
100 As mentioned earlier, we used strace to trace perf bench, stress-ng and
101 paxtest workloads to show how to analyze a workload and identify Linux
102 subsystems used by these workloads. Let's start with an overview of these
103 three workloads to get a better understanding of what they do and how to
106 perf bench (all) workload
107 -------------------------
109 The perf bench command contains multiple multi-threaded microkernel
110 benchmarks for executing different subsystems in the Linux kernel and
111 system calls. This allows us to easily measure the impact of changes,
112 which can help mitigate performance regressions. It also acts as a common
113 benchmarking framework, enabling developers to easily create test cases,
114 integrate transparently, and use performance-rich tooling subsystems.
116 Stress-ng netdev stressor workload
117 ----------------------------------
119 stress-ng is used for performing stress testing on the kernel. It allows
120 you to exercise various physical subsystems of the computer, as well as
121 interfaces of the OS kernel, using "stressor-s". They are available for
122 CPU, CPU cache, devices, I/O, interrupts, file system, memory, network,
123 operating system, pipelines, schedulers, and virtual machines. Please refer
124 to the `stress-ng man-page <https://www.mankier.com/1/stress-ng>`_ to
125 find the description of all the available stressor-s. The netdev stressor
126 starts specified number (N) of workers that exercise various netdevice
127 ioctl commands across all the available network devices.
129 paxtest kiddie workload
130 -----------------------
132 paxtest is a program that tests buffer overflows in the kernel. It tests
133 kernel enforcements over memory usage. Generally, execution in some memory
134 segments makes buffer overflows possible. It runs a set of programs that
135 attempt to subvert memory usage. It is used as a regression test suite for
136 PaX, but might be useful to test other memory protection patches for the
137 kernel. We used paxtest kiddie mode which looks for simple vulnerabilities.
139 What is strace and how do we use it?
140 ====================================
142 As mentioned earlier, strace which is a useful diagnostic, instructional,
143 and debugging tool and can be used to discover the system resources in use
144 by a workload. It can be used:
146 * To see how a process interacts with the kernel.
147 * To see why a process is failing or hanging.
148 * For reverse engineering a process.
149 * To find the files on which a program depends.
150 * For analyzing the performance of an application.
151 * For troubleshooting various problems related to the operating system.
153 In addition, strace can generate run-time statistics on times, calls, and
154 errors for each system call and report a summary when program exits,
155 suppressing the regular output. This attempts to show system time (CPU time
156 spent running in the kernel) independent of wall clock time. We plan to use
157 these features to get information on workload system usage.
159 strace command supports basic, verbose, and stats modes. strace command when
160 run in verbose mode gives more detailed information about the system calls
161 invoked by a process.
163 Running strace -c generates a report of the percentage of time spent in each
164 system call, the total time in seconds, the microseconds per call, the total
165 number of calls, the count of each system call that has failed with an error
166 and the type of system call made.
168 * Usage: strace <command we want to trace>
169 * Verbose mode usage: strace -v <command>
170 * Gather statistics: strace -c <command>
172 We used the “-c” option to gather fine-grained run-time statistics in use
173 by three workloads we have chose for this analysis.
179 What is cscope and how do we use it?
180 ====================================
182 Now let’s look at `cscope <https://cscope.sourceforge.net/>`_, a command
183 line tool for browsing C, C++ or Java code-bases. We can use it to find
184 all the references to a symbol, global definitions, functions called by a
185 function, functions calling a function, text strings, regular expression
186 patterns, files including a file.
188 We can use cscope to find which system call belongs to which subsystem.
189 This way we can find the kernel subsystems used by a process when it is
192 Let’s checkout the latest Linux repository and build cscope database::
194 git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux
196 cscope -R -p10 # builds cscope.out database before starting browse session
197 cscope -d -p10 # starts browse session on cscope.out database
199 Note: Run "cscope -R -p10" to build the database and c"scope -d -p10" to
200 enter into the browsing session. cscope by default cscope.out database.
201 To get out of this mode press ctrl+d. -p option is used to specify the
202 number of file path components to display. -p10 is optimal for browsing
205 What is perf and how do we use it?
206 ==================================
208 Perf is an analysis tool based on Linux 2.6+ systems, which abstracts the
209 CPU hardware difference in performance measurement in Linux, and provides
210 a simple command line interface. Perf is based on the perf_events interface
211 exported by the kernel. It is very useful for profiling the system and
212 finding performance bottlenecks in an application.
214 If you haven't already checked out the Linux mainline repository, you can do
215 so and then build kernel and perf tool::
217 git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux
223 Note: The perf command can be built without building the kernel in the
224 repository and can be run on older kernels. However matching the kernel
225 and perf revisions gives more accurate information on the subsystem usage.
227 We used "perf stat" and "perf bench" options. For a detailed information on
228 the perf tool, run "perf -h".
232 The perf stat command generates a report of various hardware and software
233 events. It does so with the help of hardware counter registers found in
234 modern CPUs that keep the count of these activities. "perf stat cal" shows
235 stats for cal command.
239 The perf bench command contains multiple multi-threaded microkernel
240 benchmarks for executing different subsystems in the Linux kernel and
241 system calls. This allows us to easily measure the impact of changes,
242 which can help mitigate performance regressions. It also acts as a common
243 benchmarking framework, enabling developers to easily create test cases,
244 integrate transparently, and use performance-rich tooling.
246 "perf bench all" command runs the following benchmarks:
254 What is stress-ng and how do we use it?
255 =======================================
257 As mentioned earlier, stress-ng is used for performing stress testing on
258 the kernel. It allows you to exercise various physical subsystems of the
259 computer, as well as interfaces of the OS kernel, using stressor-s. They
260 are available for CPU, CPU cache, devices, I/O, interrupts, file system,
261 memory, network, operating system, pipelines, schedulers, and virtual
264 The netdev stressor starts N workers that exercise various netdevice ioctl
265 commands across all the available network devices. The following ioctls are
268 * SIOCGIFCONF, SIOCGIFINDEX, SIOCGIFNAME, SIOCGIFFLAGS
269 * SIOCGIFADDR, SIOCGIFNETMASK, SIOCGIFMETRIC, SIOCGIFMTU
270 * SIOCGIFHWADDR, SIOCGIFMAP, SIOCGIFTXQLEN
272 The following command runs the stressor::
274 stress-ng --netdev 1 -t 60 --metrics command.
276 We can use the perf record command to record the events and information
277 associated with a process. This command records the profiling data in the
278 perf.data file in the same directory.
280 Using the following commands you can record the events associated with the
281 netdev stressor, view the generated report perf.data and annotate the to
282 view the statistics of each instruction of the program::
284 perf record stress-ng --netdev 1 -t 60 --metrics command.
288 What is paxtest and how do we use it?
289 =====================================
291 paxtest is a program that tests buffer overflows in the kernel. It tests
292 kernel enforcements over memory usage. Generally, execution in some memory
293 segments makes buffer overflows possible. It runs a set of programs that
294 attempt to subvert memory usage. It is used as a regression test suite for
295 PaX, and will be useful to test other memory protection patches for the
298 paxtest provides kiddie and blackhat modes. The paxtest kiddie mode runs
299 in normal mode, whereas the blackhat mode tries to get around the protection
300 of the kernel testing for vulnerabilities. We focus on the kiddie mode here
301 and combine "paxtest kiddie" run with "perf record" to collect CPU stack
302 traces for the paxtest kiddie run to see which function is calling other
303 functions in the performance profile. Then the "dwarf" (DWARF's Call Frame
304 Information) mode can be used to unwind the stack.
306 The following command can be used to view resulting report in call-graph
309 perf record --call-graph dwarf paxtest kiddie
315 Now that we understand the workloads, let's start tracing them.
317 Tracing perf bench all workload
318 -------------------------------
320 Run the following command to trace perf bench all workload::
322 strace -c perf bench all
324 **System Calls made by the workload**
326 The below table shows the system calls invoked by the workload, number of
327 times each system call is invoked, and the corresponding Linux subsystem.
329 +-------------------+-----------+-----------------+-------------------------+
330 | System Call | # calls | Linux Subsystem | System Call (API) |
331 +===================+===========+=================+=========================+
332 | getppid | 10000001 | Process Mgmt | sys_getpid() |
333 +-------------------+-----------+-----------------+-------------------------+
334 | clone | 1077 | Process Mgmt. | sys_clone() |
335 +-------------------+-----------+-----------------+-------------------------+
336 | prctl | 23 | Process Mgmt. | sys_prctl() |
337 +-------------------+-----------+-----------------+-------------------------+
338 | prlimit64 | 7 | Process Mgmt. | sys_prlimit64() |
339 +-------------------+-----------+-----------------+-------------------------+
340 | getpid | 10 | Process Mgmt. | sys_getpid() |
341 +-------------------+-----------+-----------------+-------------------------+
342 | uname | 3 | Process Mgmt. | sys_uname() |
343 +-------------------+-----------+-----------------+-------------------------+
344 | sysinfo | 1 | Process Mgmt. | sys_sysinfo() |
345 +-------------------+-----------+-----------------+-------------------------+
346 | getuid | 1 | Process Mgmt. | sys_getuid() |
347 +-------------------+-----------+-----------------+-------------------------+
348 | getgid | 1 | Process Mgmt. | sys_getgid() |
349 +-------------------+-----------+-----------------+-------------------------+
350 | geteuid | 1 | Process Mgmt. | sys_geteuid() |
351 +-------------------+-----------+-----------------+-------------------------+
352 | getegid | 1 | Process Mgmt. | sys_getegid |
353 +-------------------+-----------+-----------------+-------------------------+
354 | close | 49951 | Filesystem | sys_close() |
355 +-------------------+-----------+-----------------+-------------------------+
356 | pipe | 604 | Filesystem | sys_pipe() |
357 +-------------------+-----------+-----------------+-------------------------+
358 | openat | 48560 | Filesystem | sys_opennat() |
359 +-------------------+-----------+-----------------+-------------------------+
360 | fstat | 8338 | Filesystem | sys_fstat() |
361 +-------------------+-----------+-----------------+-------------------------+
362 | stat | 1573 | Filesystem | sys_stat() |
363 +-------------------+-----------+-----------------+-------------------------+
364 | pread64 | 9646 | Filesystem | sys_pread64() |
365 +-------------------+-----------+-----------------+-------------------------+
366 | getdents64 | 1873 | Filesystem | sys_getdents64() |
367 +-------------------+-----------+-----------------+-------------------------+
368 | access | 3 | Filesystem | sys_access() |
369 +-------------------+-----------+-----------------+-------------------------+
370 | lstat | 1880 | Filesystem | sys_lstat() |
371 +-------------------+-----------+-----------------+-------------------------+
372 | lseek | 6 | Filesystem | sys_lseek() |
373 +-------------------+-----------+-----------------+-------------------------+
374 | ioctl | 3 | Filesystem | sys_ioctl() |
375 +-------------------+-----------+-----------------+-------------------------+
376 | dup2 | 1 | Filesystem | sys_dup2() |
377 +-------------------+-----------+-----------------+-------------------------+
378 | execve | 2 | Filesystem | sys_execve() |
379 +-------------------+-----------+-----------------+-------------------------+
380 | fcntl | 8779 | Filesystem | sys_fcntl() |
381 +-------------------+-----------+-----------------+-------------------------+
382 | statfs | 1 | Filesystem | sys_statfs() |
383 +-------------------+-----------+-----------------+-------------------------+
384 | epoll_create | 2 | Filesystem | sys_epoll_create() |
385 +-------------------+-----------+-----------------+-------------------------+
386 | epoll_ctl | 64 | Filesystem | sys_epoll_ctl() |
387 +-------------------+-----------+-----------------+-------------------------+
388 | newfstatat | 8318 | Filesystem | sys_newfstatat() |
389 +-------------------+-----------+-----------------+-------------------------+
390 | eventfd2 | 192 | Filesystem | sys_eventfd2() |
391 +-------------------+-----------+-----------------+-------------------------+
392 | mmap | 243 | Memory Mgmt. | sys_mmap() |
393 +-------------------+-----------+-----------------+-------------------------+
394 | mprotect | 32 | Memory Mgmt. | sys_mprotect() |
395 +-------------------+-----------+-----------------+-------------------------+
396 | brk | 21 | Memory Mgmt. | sys_brk() |
397 +-------------------+-----------+-----------------+-------------------------+
398 | munmap | 128 | Memory Mgmt. | sys_munmap() |
399 +-------------------+-----------+-----------------+-------------------------+
400 | set_mempolicy | 156 | Memory Mgmt. | sys_set_mempolicy() |
401 +-------------------+-----------+-----------------+-------------------------+
402 | set_tid_address | 1 | Process Mgmt. | sys_set_tid_address() |
403 +-------------------+-----------+-----------------+-------------------------+
404 | set_robust_list | 1 | Futex | sys_set_robust_list() |
405 +-------------------+-----------+-----------------+-------------------------+
406 | futex | 341 | Futex | sys_futex() |
407 +-------------------+-----------+-----------------+-------------------------+
408 | sched_getaffinity | 79 | Scheduler | sys_sched_getaffinity() |
409 +-------------------+-----------+-----------------+-------------------------+
410 | sched_setaffinity | 223 | Scheduler | sys_sched_setaffinity() |
411 +-------------------+-----------+-----------------+-------------------------+
412 | socketpair | 202 | Network | sys_socketpair() |
413 +-------------------+-----------+-----------------+-------------------------+
414 | rt_sigprocmask | 21 | Signal | sys_rt_sigprocmask() |
415 +-------------------+-----------+-----------------+-------------------------+
416 | rt_sigaction | 36 | Signal | sys_rt_sigaction() |
417 +-------------------+-----------+-----------------+-------------------------+
418 | rt_sigreturn | 2 | Signal | sys_rt_sigreturn() |
419 +-------------------+-----------+-----------------+-------------------------+
420 | wait4 | 889 | Time | sys_wait4() |
421 +-------------------+-----------+-----------------+-------------------------+
422 | clock_nanosleep | 37 | Time | sys_clock_nanosleep() |
423 +-------------------+-----------+-----------------+-------------------------+
424 | capget | 4 | Capability | sys_capget() |
425 +-------------------+-----------+-----------------+-------------------------+
427 Tracing stress-ng netdev stressor workload
428 ------------------------------------------
430 Run the following command to trace stress-ng netdev stressor workload::
432 strace -c stress-ng --netdev 1 -t 60 --metrics
434 **System Calls made by the workload**
436 The below table shows the system calls invoked by the workload, number of
437 times each system call is invoked, and the corresponding Linux subsystem.
439 +-------------------+-----------+-----------------+-------------------------+
440 | System Call | # calls | Linux Subsystem | System Call (API) |
441 +===================+===========+=================+=========================+
442 | openat | 74 | Filesystem | sys_openat() |
443 +-------------------+-----------+-----------------+-------------------------+
444 | close | 75 | Filesystem | sys_close() |
445 +-------------------+-----------+-----------------+-------------------------+
446 | read | 58 | Filesystem | sys_read() |
447 +-------------------+-----------+-----------------+-------------------------+
448 | fstat | 20 | Filesystem | sys_fstat() |
449 +-------------------+-----------+-----------------+-------------------------+
450 | flock | 10 | Filesystem | sys_flock() |
451 +-------------------+-----------+-----------------+-------------------------+
452 | write | 7 | Filesystem | sys_write() |
453 +-------------------+-----------+-----------------+-------------------------+
454 | getdents64 | 8 | Filesystem | sys_getdents64() |
455 +-------------------+-----------+-----------------+-------------------------+
456 | pread64 | 8 | Filesystem | sys_pread64() |
457 +-------------------+-----------+-----------------+-------------------------+
458 | lseek | 1 | Filesystem | sys_lseek() |
459 +-------------------+-----------+-----------------+-------------------------+
460 | access | 2 | Filesystem | sys_access() |
461 +-------------------+-----------+-----------------+-------------------------+
462 | getcwd | 1 | Filesystem | sys_getcwd() |
463 +-------------------+-----------+-----------------+-------------------------+
464 | execve | 1 | Filesystem | sys_execve() |
465 +-------------------+-----------+-----------------+-------------------------+
466 | mmap | 61 | Memory Mgmt. | sys_mmap() |
467 +-------------------+-----------+-----------------+-------------------------+
468 | munmap | 3 | Memory Mgmt. | sys_munmap() |
469 +-------------------+-----------+-----------------+-------------------------+
470 | mprotect | 20 | Memory Mgmt. | sys_mprotect() |
471 +-------------------+-----------+-----------------+-------------------------+
472 | mlock | 2 | Memory Mgmt. | sys_mlock() |
473 +-------------------+-----------+-----------------+-------------------------+
474 | brk | 3 | Memory Mgmt. | sys_brk() |
475 +-------------------+-----------+-----------------+-------------------------+
476 | rt_sigaction | 21 | Signal | sys_rt_sigaction() |
477 +-------------------+-----------+-----------------+-------------------------+
478 | rt_sigprocmask | 1 | Signal | sys_rt_sigprocmask() |
479 +-------------------+-----------+-----------------+-------------------------+
480 | sigaltstack | 1 | Signal | sys_sigaltstack() |
481 +-------------------+-----------+-----------------+-------------------------+
482 | rt_sigreturn | 1 | Signal | sys_rt_sigreturn() |
483 +-------------------+-----------+-----------------+-------------------------+
484 | getpid | 8 | Process Mgmt. | sys_getpid() |
485 +-------------------+-----------+-----------------+-------------------------+
486 | prlimit64 | 5 | Process Mgmt. | sys_prlimit64() |
487 +-------------------+-----------+-----------------+-------------------------+
488 | arch_prctl | 2 | Process Mgmt. | sys_arch_prctl() |
489 +-------------------+-----------+-----------------+-------------------------+
490 | sysinfo | 2 | Process Mgmt. | sys_sysinfo() |
491 +-------------------+-----------+-----------------+-------------------------+
492 | getuid | 2 | Process Mgmt. | sys_getuid() |
493 +-------------------+-----------+-----------------+-------------------------+
494 | uname | 1 | Process Mgmt. | sys_uname() |
495 +-------------------+-----------+-----------------+-------------------------+
496 | setpgid | 1 | Process Mgmt. | sys_setpgid() |
497 +-------------------+-----------+-----------------+-------------------------+
498 | getrusage | 1 | Process Mgmt. | sys_getrusage() |
499 +-------------------+-----------+-----------------+-------------------------+
500 | geteuid | 1 | Process Mgmt. | sys_geteuid() |
501 +-------------------+-----------+-----------------+-------------------------+
502 | getppid | 1 | Process Mgmt. | sys_getppid() |
503 +-------------------+-----------+-----------------+-------------------------+
504 | sendto | 3 | Network | sys_sendto() |
505 +-------------------+-----------+-----------------+-------------------------+
506 | connect | 1 | Network | sys_connect() |
507 +-------------------+-----------+-----------------+-------------------------+
508 | socket | 1 | Network | sys_socket() |
509 +-------------------+-----------+-----------------+-------------------------+
510 | clone | 1 | Process Mgmt. | sys_clone() |
511 +-------------------+-----------+-----------------+-------------------------+
512 | set_tid_address | 1 | Process Mgmt. | sys_set_tid_address() |
513 +-------------------+-----------+-----------------+-------------------------+
514 | wait4 | 2 | Time | sys_wait4() |
515 +-------------------+-----------+-----------------+-------------------------+
516 | alarm | 1 | Time | sys_alarm() |
517 +-------------------+-----------+-----------------+-------------------------+
518 | set_robust_list | 1 | Futex | sys_set_robust_list() |
519 +-------------------+-----------+-----------------+-------------------------+
521 Tracing paxtest kiddie workload
522 -------------------------------
524 Run the following command to trace paxtest kiddie workload::
526 strace -c paxtest kiddie
528 **System Calls made by the workload**
530 The below table shows the system calls invoked by the workload, number of
531 times each system call is invoked, and the corresponding Linux subsystem.
533 +-------------------+-----------+-----------------+----------------------+
534 | System Call | # calls | Linux Subsystem | System Call (API) |
535 +===================+===========+=================+======================+
536 | read | 3 | Filesystem | sys_read() |
537 +-------------------+-----------+-----------------+----------------------+
538 | write | 11 | Filesystem | sys_write() |
539 +-------------------+-----------+-----------------+----------------------+
540 | close | 41 | Filesystem | sys_close() |
541 +-------------------+-----------+-----------------+----------------------+
542 | stat | 24 | Filesystem | sys_stat() |
543 +-------------------+-----------+-----------------+----------------------+
544 | fstat | 2 | Filesystem | sys_fstat() |
545 +-------------------+-----------+-----------------+----------------------+
546 | pread64 | 6 | Filesystem | sys_pread64() |
547 +-------------------+-----------+-----------------+----------------------+
548 | access | 1 | Filesystem | sys_access() |
549 +-------------------+-----------+-----------------+----------------------+
550 | pipe | 1 | Filesystem | sys_pipe() |
551 +-------------------+-----------+-----------------+----------------------+
552 | dup2 | 24 | Filesystem | sys_dup2() |
553 +-------------------+-----------+-----------------+----------------------+
554 | execve | 1 | Filesystem | sys_execve() |
555 +-------------------+-----------+-----------------+----------------------+
556 | fcntl | 26 | Filesystem | sys_fcntl() |
557 +-------------------+-----------+-----------------+----------------------+
558 | openat | 14 | Filesystem | sys_openat() |
559 +-------------------+-----------+-----------------+----------------------+
560 | rt_sigaction | 7 | Signal | sys_rt_sigaction() |
561 +-------------------+-----------+-----------------+----------------------+
562 | rt_sigreturn | 38 | Signal | sys_rt_sigreturn() |
563 +-------------------+-----------+-----------------+----------------------+
564 | clone | 38 | Process Mgmt. | sys_clone() |
565 +-------------------+-----------+-----------------+----------------------+
566 | wait4 | 44 | Time | sys_wait4() |
567 +-------------------+-----------+-----------------+----------------------+
568 | mmap | 7 | Memory Mgmt. | sys_mmap() |
569 +-------------------+-----------+-----------------+----------------------+
570 | mprotect | 3 | Memory Mgmt. | sys_mprotect() |
571 +-------------------+-----------+-----------------+----------------------+
572 | munmap | 1 | Memory Mgmt. | sys_munmap() |
573 +-------------------+-----------+-----------------+----------------------+
574 | brk | 3 | Memory Mgmt. | sys_brk() |
575 +-------------------+-----------+-----------------+----------------------+
576 | getpid | 1 | Process Mgmt. | sys_getpid() |
577 +-------------------+-----------+-----------------+----------------------+
578 | getuid | 1 | Process Mgmt. | sys_getuid() |
579 +-------------------+-----------+-----------------+----------------------+
580 | getgid | 1 | Process Mgmt. | sys_getgid() |
581 +-------------------+-----------+-----------------+----------------------+
582 | geteuid | 2 | Process Mgmt. | sys_geteuid() |
583 +-------------------+-----------+-----------------+----------------------+
584 | getegid | 1 | Process Mgmt. | sys_getegid() |
585 +-------------------+-----------+-----------------+----------------------+
586 | getppid | 1 | Process Mgmt. | sys_getppid() |
587 +-------------------+-----------+-----------------+----------------------+
588 | arch_prctl | 2 | Process Mgmt. | sys_arch_prctl() |
589 +-------------------+-----------+-----------------+----------------------+
594 This document is intended to be used as a guide on how to gather fine-grained
595 information on the resources in use by workloads using strace.
600 * `Discovery Linux Kernel Subsystems used by OpenAPS <https://elisa.tech/blog/2022/02/02/discovery-linux-kernel-subsystems-used-by-openaps>`_
601 * `ELISA-White-Papers-Discovering Linux kernel subsystems used by a workload <https://github.com/elisa-tech/ELISA-White-Papers/blob/master/Processes/Discovering_Linux_kernel_subsystems_used_by_a_workload.md>`_
602 * `strace <https://man7.org/linux/man-pages/man1/strace.1.html>`_
603 * `perf <https://man7.org/linux/man-pages/man1/perf.1.html>`_
604 * `paxtest README <https://github.com/opntr/paxtest-freebsd/blob/hardenedbsd/0.9.14-hbsd/README>`_
605 * `stress-ng <https://www.mankier.com/1/stress-ng>`_
606 * `Monitoring and managing system status and performance <https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/monitoring_and_managing_system_status_and_performance/index>`_
projects / platform / kernel / linux-starfive.git / blob