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2022-07-31rtla: Define syscall numbers for riscvAndreas Schwab1-1/+1
RISC-V uses the same (generic) syscall numbers as ARM64. Link: https://lkml.kernel.org/r/mvma68wl2ul.fsf@suse.de Signed-off-by: Andreas Schwab <schwab@suse.de> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-31rtla: Fix double freeAndreas Schwab1-2/+7
Avoid double free by making trace_instance_destroy indempotent. When trace_instance_init fails, it calls trace_instance_destroy, but its only caller osnoise_destroy_tool calls it again. Link: https://lkml.kernel.org/r/mvmilnlkyzx.fsf_-_@suse.de Fixes: 0605bf009f18 ("rtla: Add osnoise tool") Signed-off-by: Andreas Schwab <schwab@suse.de> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-31rtla: Fix Makefile when called from -C tools/Daniel Bristot de Oliveira1-1/+1
Sedat Dilek reported an error on rtla Makefile when running: $ make -C tools/ clean [...] make[2]: Entering directory '/home/dileks/src/linux-kernel/git/tools/tracing/rtla' [...] '/home/dileks/src/linux-kernel/git/Documentation/tools/rtla' /bin/sh: 1: test: rtla-make[2]:: unexpected operator <------ The problem rm: cannot remove '/home/dileks/src/linux-kernel/git': Is a directory make[2]: *** [Makefile:120: clean] Error 1 make[2]: Leaving directory This occurred because the rtla calls kernel's Makefile to get the version in silence mode, e.g., $ make -sC ../../.. kernelversion 5.19.0-rc4 But the -s is being ignored when rtla's makefile is called indirectly, so the output looks like this: $ make -C ../../.. kernelversion make: Entering directory '/root/linux' 5.19.0-rc4 make: Leaving directory '/root/linux' Using 'grep -v make' avoids this problem, e.g., $ make -C ../../.. kernelversion | grep -v make 5.19.0-rc4 Thus, add | grep -v make. Link: https://lkml.kernel.org/r/870c02d4d97a921f02a31fa3b229fc549af61a20.1657747763.git.bristot@kernel.org Fixes: 8619e32825fd ("rtla: Follow kernel version") Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-11rtla/utils: Use calloc and check the potential memory allocation failurejianchunfu1-2/+3
Replace malloc with calloc and add memory allocating check of mon_cpus before used. Link: https://lkml.kernel.org/r/20220615073348.6891-1-jianchunfu@cmss.chinamobile.com Fixes: 7d0dc9576dc3 ("rtla/timerlat: Add --dma-latency option") Signed-off-by: jianchunfu <jianchunfu@cmss.chinamobile.com> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-05-26rtla: Remove procps-ng dependencyDaniel Bristot de Oliveira4-24/+88
Daniel Wagner reported to me that readproc.h got deprecated. Also, while the procps-ng library was available on Fedora, it was not available on RHEL, which is a piece of evidence that it was not that used. rtla uses procps-ng only to find the PID of the tracers' workload. I used the procps-ng library to avoid reinventing the wheel. But in this case, reinventing the wheel took me less time than the time we already took trying to work around problems. Implement a function that reads /proc/ entries, checking if: - the entry is a directory - the directory name is composed only of digits (PID) - the directory contains the comm file - the comm file contains a comm that matches the tracers' workload prefix. - then return true; otherwise, return false. And use it instead of procps-ng. Link: https://lkml.kernel.org/r/e8276e122ee9eb2c5a0ba8e673fb6488b924b825.1652423574.git.bristot@kernel.org Cc: John Kacur <jkacur@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tao Zhou <tao.zhou@linux.dev> Fixes: b1696371d865 ("rtla: Helper functions for rtla") Reported-by: Daniel Wagner <dwagner@suse.de> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-05-26rtla: Fix __set_sched_attr error messageDaniel Bristot de Oliveira1-1/+1
rtla's function __set_sched_attr() was borrowed from stalld, but I forgot to update the error message to something meaningful for rtla. Update the error message from: boost_with_deadline failed to boost pid PID: STRERROR to a proper one: Failed to set sched attributes to the pid PID: STRERROR Link: https://lkml.kernel.org/r/a2d19b2c53f6512aefd1ee7f8c1bd19d4fc8b99d.1651247710.git.bristot@kernel.org Link: https://lore.kernel.org/r/eeded730413e7feaa13f946924bcf2cbf7dd9561.1650617571.git.bristot@kernel.org/ Fixes: b1696371d865 ("rtla: Helper functions for rtla") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-05-26rtla: Minor grammar fix for rtla READMEJohn Kacur1-7/+5
- Change to "The rtla meta-tool includes" - Remove an unnecessary "But, " - Adjust the formatting of the paragraph resulting from the changes. - Simplify the wording for the libraries and tools. Link: https://lkml.kernel.org/r/437f0accdde53713ab3cce46f3564be00487e031.1651247710.git.bristot@kernel.org Link: https://lore.kernel.org/r/20220408161012.10544-1-jkacur@redhat.com/ Cc: Daniel Bristot de Oliveria <bristot@kernel.org> Fixes: 79ce8f43ac5a ("rtla: Real-Time Linux Analysis tool") Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: John Kacur <jkacur@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-05-26rtla: Don't overwrite existing directory modeJohn Kacur1-1/+2
The mode on /usr/bin is often 555 these days, but make install on rtla overwrites this with 755 Fix this by preserving the current directory if it exists. Link: https://lkml.kernel.org/r/8c294a6961080a1970fd8b73f7bcf1e3984579e2.1651247710.git.bristot@kernel.org Link: https://lore.kernel.org/r/20220402043939.6962-1-jkacur@redhat.com Cc: Daniel Bristot de Oliveria <bristot@redhat.com> Fixes: 79ce8f43ac5a ("rtla: Real-Time Linux Analysis tool") Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: John Kacur <jkacur@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-05-26rtla: Avoid record NULL pointer dereferenceWan Jiabing4-16/+20
Fix the following null/deref_null.cocci errors: ./tools/tracing/rtla/src/osnoise_hist.c:870:31-36: ERROR: record is NULL but dereferenced. ./tools/tracing/rtla/src/osnoise_top.c:650:31-36: ERROR: record is NULL but dereferenced. ./tools/tracing/rtla/src/timerlat_hist.c:905:31-36: ERROR: record is NULL but dereferenced. ./tools/tracing/rtla/src/timerlat_top.c:700:31-36: ERROR: record is NULL but dereferenced. "record" is NULL before calling osnoise_init_trace_tool. Add a tag "out_free" to avoid dereferring a NULL pointer. Link: https://lkml.kernel.org/r/ae0e4500d383db0884eb2820286afe34ca303778.1651247710.git.bristot@kernel.org Link: https://lore.kernel.org/r/20220408151406.34823-1-wanjiabing@vivo.com/ Cc: kael_w@yeah.net Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Fixes: 51d64c3a1819 ("rtla: Add -e/--event support") Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-05-26rtla/Makefile: Properly handle dependenciesDaniel Bristot de Oliveira1-0/+35
Linus had a problem compiling RTLA, saying: "[...] I wish the tracing tools would do a bit more package checking and helpful error messages too, rather than just fail with: fatal error: tracefs.h: No such file or directory" Which is indeed not a helpful message. Update the Makefile, adding proper checks for the dependencies, with useful information about how to resolve possible problems. For example, the previous error is now reported as: $ make ******************************************** ** NOTICE: libtracefs version 1.3 or higher not found ** ** Consider installing the latest libtracefs from your ** distribution, e.g., 'dnf install libtracefs' on Fedora, ** or from source: ** ** https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/ ** ******************************************** These messages are inspired by the ones used on trace-cmd, as suggested by Stevel Rostedt. Link: https://lore.kernel.org/r/CAHk-=whxmA86E=csNv76DuxX_wYsg8mW15oUs3XTabu2Yc80yw@mail.gmail.com/ Changes from V1: - Moved the rst2man check to the install phase (when it is used). - Removed the procps-ng lib check [1] as it is being removed. [1] a0f9f8c1030c66305c9b921057c3d483064d5529.1651220820.git.bristot@kernel.org Link: https://lkml.kernel.org/r/3f1fac776c37e4b67c876a94e5a0e45ed022ff3d.1651238057.git.bristot@kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-31Merge tag 'kbuild-v5.18-v2' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add new environment variables, USERCFLAGS and USERLDFLAGS to allow additional flags to be passed to user-space programs. - Fix missing fflush() bugs in Kconfig and fixdep - Fix a minor bug in the comment format of the .config file - Make kallsyms ignore llvm's local labels, .L* - Fix UAPI compile-test for cross-compiling with Clang - Extend the LLVM= syntax to support LLVM=<suffix> form for using a particular version of LLVm, and LLVM=<prefix> form for using custom LLVM in a particular directory path. - Clean up Makefiles * tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: Make $(LLVM) more flexible kbuild: add --target to correctly cross-compile UAPI headers with Clang fixdep: use fflush() and ferror() to ensure successful write to files arch: syscalls: simplify uapi/kapi directory creation usr/include: replace extra-y with always-y certs: simplify empty certs creation in certs/Makefile certs: include certs/signing_key.x509 unconditionally kallsyms: ignore all local labels prefixed by '.L' kconfig: fix missing '# end of' for empty menu kconfig: add fflush() before ferror() check kbuild: replace $(if A,A,B) with $(or A,B) kbuild: Add environment variables for userprogs flags kbuild: unify cmd_copy and cmd_shipped
2022-03-15rtla: Tools main loop cleanupDaniel Bristot de Oliveira4-5/+5
I probably started using "do {} while();", but changed all but osnoise_top to "while(){};" leaving the ; behind. Cleanup the main loop code, making all tools use "while() {}" Changcheng Deng reported this problem, as reported by coccicheck: Fix the following coccicheck review: ./tools/tracing/rtla/src/timerlat_hist.c: 800: 2-3: Unneeded semicolon ./tools/tracing/rtla/src/osnoise_hist.c: 776: 2-3: Unneeded semicolon ./tools/tracing/rtla/src/timerlat_top.c: 596: 2-3: Unneeded semicolon Link: https://lkml.kernel.org/r/3c1642110aa87c396f5da4a037dabc72dbb9c601.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Reported-by: Changcheng Deng <deng.changcheng@zte.com.cn> Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/timerlat: Add --dma-latency optionDaniel Bristot de Oliveira4-4/+86
Add the --dma-latency to set /dev/cpu_dma_latency to the specified value, this aims to avoid having exit from idle states latencies that could be influencing the analysis. Link: https://lkml.kernel.org/r/72ddb0d913459f13217086dadafad88a7c46dd28.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/osnoise: Fix osnoise hist stop tracing messageDaniel Bristot de Oliveira1-1/+1
rtla osnoise hist is printing the following message when hitting stop tracing: printf("rtla timelat hit stop tracing\n"); which is obviosly wrong. s/timerlat/osnoise/ fixing the printf. Link: https://lkml.kernel.org/r/2b8f090556fe37b81d183b74ce271421f131c77b.1646247211.git.bristot@kernel.org Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode") Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla: Check for trace off also in the trace instanceDaniel Bristot de Oliveira6-8/+28
With the addition of --trigger option, it is also possible to stop the trace from the -t tracing instance using the traceoff trigger. Make rtla tools to check if the trace is stopped also in the trace instance, stopping the execution of the tool. Link: https://lkml.kernel.org/r/59fc7c6f23dddd5c8b7ef1782cf3da51ea2ce0f5.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/trace: Save event histogram output to a fileDaniel Bristot de Oliveira1-0/+53
The hist: trigger generates a histogram in the file sys/event/hist. If the hist: trigger is used, automatically save the histogram output of the event sys:event in the sys_event_hist.txt file. Link: https://lkml.kernel.org/r/b5c906af31d4e022ffe87fb0848fac5c089087c8.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla: Add --filter supportDaniel Bristot de Oliveira4-10/+66
Add --filter option. This option enables a trace event filtering of the previous -e sys:event argument. This option is available for all current tools. Link: https://lkml.kernel.org/r/509d70b6348d3e5bcbf1f07ab725ce08d063149a.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/trace: Add trace event filter helpersDaniel Bristot de Oliveira2-0/+86
Add a set of helper functions to allow rtla tools to filter events in the trace instance. Link: https://lkml.kernel.org/r/12623b1684684549d53b90f4bf66fae44584fd14.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla: Add --trigger supportDaniel Bristot de Oliveira4-10/+62
Add --trigger option. This option enables a trace event trigger to the previous -e sys:event argument, allowing some advanced tracing options. For instance, in a system with CPUs 2:23 isolated, it is possible to get a stack trace of thread wakeup targeting those CPUs while running osnoise with the following command line: # osnoise top -c 2-23 -a 50 -e sched:sched_wakeup --trigger="stacktrace if target_cpu >= 2" This option is available for all current tools. Link: https://lkml.kernel.org/r/07d2983d5f71261d4da89dbaf02efcad100ab8ee.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/trace: Add trace event trigger helpersDaniel Bristot de Oliveira2-1/+91
Add a set of helper functions to allow rtla tools to trigger event actions in the trace instance. Link: https://lkml.kernel.org/r/e0d31abe879a78a5600b64f904d0dfa8f76e4fbb.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla: Add -e/--event supportDaniel Bristot de Oliveira4-11/+110
Add -e/--event option. This option enables an event in the trace (-t) session. The argument can be a specific event, e.g., -e sched:sched_switch, or all events of a system group, e.g., -e sched. Multiple -e are allowed. It is only active when -t or -a are set. This option is available for all current tools. Link: https://lkml.kernel.org/r/6a3b753be9b1e811953995f7f21a86918ad13390.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/trace: Add trace events helpersDaniel Bristot de Oliveira2-0/+119
Add a set of helper functions to allow the rtla tools to enable additional tracepoints in the trace instance. Link: https://lkml.kernel.org/r/932398b36c1bbaa22c7810d7a40ca9b8c5595b94.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/timerlat: Add the automatic trace optionDaniel Bristot de Oliveira2-7/+39
Add the -a/--auto <arg in us> option. This option sets some commonly used options while debugging the system. It aims to help users produce reports in the field, reducing the number of arguments passed to the tool in the first approach to a problem. It is equivalent to setting osnoise/stop_tracing_total_us and print_stack with the argument, and saving the trace to timerlat_trace.txt file if the trace is stopped automatically. Link: https://lkml.kernel.org/r/92438f7ef132c731f538cebdf77850300afe04a5.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/osnoise: Add the automatic trace optionDaniel Bristot de Oliveira2-6/+32
Add the -a/--auto <arg in us> option. This option sets some commonly used options while debugging the system. It aims to help users produce reports in the field, reducing the number of arguments passed to the tool in the first approach to a problem. It is equivalent to setting osnoise/stop_tracing_us with the argument, setting tracing_thresh to 1 us, and saving the trace to osnoise_trace.txt file if the trace is stopped automatically. Link: https://lkml.kernel.org/r/ef04c961b227eb93a83cd0b54bfca45e1a381b77.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/osnoise: Add an option to set the thresholdDaniel Bristot de Oliveira2-7/+35
Add the -T/--threshold option to set the minimum threshold to be considered a noise to osnoise top and hist commands. Also update the man pages. Link: https://lkml.kernel.org/r/031861200ffdb24a1df4aa72c458706889a20d5d.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/osnoise: Add support to adjust the tracing_threshDaniel Bristot de Oliveira2-0/+91
osnoise uses the tracing_thresh parameter to define the delta between two reads of the time to be considered a noise. Add support to get and set the tracing_thresh from osnoise tools. Link: https://lkml.kernel.org/r/715ad2a53fd40e41bab8c3f1214c1a94e12fb595.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25rtla/osnoise: Fix error message when failing to enable trace instanceDaniel Bristot de Oliveira1-1/+1
When a trace instance creation fails, tools are printing: Could not enable -> osnoiser <- tracer for tracing Print the actual (and correct) name of the tracer it fails to enable. Link: https://lkml.kernel.org/r/53ef0582605af91eca14b19dba9fc9febb95d4f9.1645206561.git.bristot@kernel.org Fixes: b1696371d865 ("rtla: Helper functions for rtla") Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25rtla/osnoise: Free params at the exitDaniel Bristot de Oliveira1-0/+1
The variable that stores the parsed command line arguments are not being free()d at the rtla osnoise top exit path. Free params variable before exiting. Link: https://lkml.kernel.org/r/0be31d8259c7c53b98a39769d60cfeecd8421785.1645206561.git.bristot@kernel.org Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode") Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25rtla/hist: Make -E the short version of --entriesDaniel Bristot de Oliveira2-10/+10
Currently, --entries uses -e as the short version in the hist mode of timerlat and osnoise tools. But as -e is already used to enable events on trace sessions by other tools, thus let's keep it available for the same usage for all rtla tools. Make -E the short version of --entries for hist mode on all tools. Note: rtla was merged in this merge window, so rtla was not released yet. Link: https://lkml.kernel.org/r/5dbf0cbe7364d3a05e708926b41a097c59a02b1e.1645206561.git.bristot@kernel.org Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-15kbuild: replace $(if A,A,B) with $(or A,B)Masahiro Yamada1-1/+1
$(or ...) is available since GNU Make 3.81, and useful to shorten the code in some places. Covert as follows: $(if A,A,B) --> $(or A,B) This patch also converts: $(if A, A, B) --> $(or A, B) Strictly speaking, the latter is not an equivalent conversion because GNU Make keeps spaces after commas; if A is not empty, $(if A, A, B) expands to " A", while $(or A, B) expands to "A". Anyway, preceding spaces are not significant in the code hunks I touched. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-02-08rtla: Fix segmentation fault when failing to enable -tDaniel Bristot de Oliveira5-16/+15
rtla osnoise and timerlat are causing a segmentation fault when running with the --trace option on a kernel that does not support multiple instances. For example: [root@f34 rtla]# rtla osnoise top -t failed to enable the tracer osnoise Could not enable osnoiser tracer for tracing Failed to enable the trace instance Segmentation fault (core dumped) This error happens because the exit code of the tools is trying to destroy the trace instance that failed to be created. Make osnoise_destroy_tool() aware of possible NULL osnoise_tool *, and do not attempt to destroy it. This also simplifies the exit code. Link: https://lkml.kernel.org/r/5660a2b6bf66c2655842360f2d7f6b48db5dba23.1644327249.git.bristot@kernel.org Suggested-by: Steven Rostedt <rostedt@goodmis.org> Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode") Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode") Fixes: a828cd18bc4a ("rtla: Add timerlat tool and timelart top mode") Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-04rtla/trace: Error message fixupDaniel Bristot de Oliveira1-4/+4
Use capital and change "tracer %s" to "%s tracer". No functional change. Link: https://lkml.kernel.org/r/361697d27431afefa64c67c323564205385c418d.1643990447.git.bristot@kernel.org Fixes: b1696371d865 ("rtla: Helper functions for rtla") Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-kernel@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-04rtla/utils: Fix session duration parsingDaniel Bristot de Oliveira1-2/+2
Use gmtime to format the duration time. This avoids problems when the system uses local time different of Pisa's Local Time. Link: https://lkml.kernel.org/r/a2f0a37bc006c2561bb8ecd871cd70532b4a9f2d.1643990447.git.bristot@kernel.org Fixes: b1696371d865 ("rtla: Helper functions for rtla") Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-kernel@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-04rtla: Follow kernel versionDaniel Bristot de Oliveira1-1/+3
To avoid having commits with new version, it is just easier to follow kernel version. Link: https://lkml.kernel.org/r/9c2df0d1de65cea96c7d731fe64781a2bb90c5b3.1643990447.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-kernel@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27tools/tracing: Update Makefile to build rtlaShuah Khan1-4/+14
Update tracing Makefile to build/install/clean rtla tragets. Link: https://lkml.kernel.org/r/20220126002234.79337-1-skhan@linuxfoundation.org Reviewed-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27rtla: Make doc build optionalShuah Khan1-1/+1
rtla build fails due to doc build dependency on rst2man. Make doc build optional so rtla could be built without docs. Leave the install dependency on doc_install alone. Link: https://lkml.kernel.org/r/20220126001301.79096-1-skhan@linuxfoundation.org Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-13rtla: Add DocumentationDaniel Bristot de Oliveira1-4/+26
Adds the basis for rtla documentation. This patch also includes the rtla(1) man page. As suggested by Jonathan Corbet, we are placing these man pages at Documentation/tools/rtla, using rst format. It is not linked to the official documentation, though. The Makefile is based on bpftool's Documentation one. Link: https://lkml.kernel.org/r/5f510f3e962fc0cd531c43f5a815544dd720c3f2.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Suggested-by: Steven Rostedt <rostedt@goodmis.org> Suggested-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13rtla/timerlat: Add timerlat hist modeDaniel Bristot de Oliveira3-2/+828
The rtla hist hist mode displays a histogram of each tracer event occurrence, both for IRQ and timer latencies. The tool also allows many configurations of the timerlat tracer and the collection of the tracer output. Here is one example of the rtla timerlat hist mode output: ---------- %< ---------- [root@alien ~]# rtla timerlat hist -c 0-3 -d 1M # RTLA timerlat histogram # Time unit is microseconds (us) # Duration: 0 00:01:00 Index IRQ-000 Thr-000 IRQ-001 Thr-001 IRQ-002 Thr-002 IRQ-003 Thr-003 0 58572 0 59373 0 58691 0 58895 0 1 1422 57021 628 57241 1310 56160 1102 56805 2 6 2931 0 2695 0 3567 4 3031 3 1 40 0 53 0 260 0 142 4 0 7 0 5 0 6 0 17 5 0 2 0 5 0 7 0 4 6 0 0 0 2 0 1 0 1 8 0 0 0 0 0 0 0 1 over: 0 0 0 0 0 0 0 0 count: 60001 60001 60001 60001 60001 60001 60001 60001 min: 0 1 0 1 0 1 0 1 avg: 0 1 0 1 0 1 0 1 max: 3 5 1 6 1 6 2 8 ---------- >% ---------- Running - rtla timerlat hist --help provides information about the available options. Link: https://lkml.kernel.org/r/7049ed3c46b7d6aceab18ffe7770003dfc4ddceb.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13rtla: Add timerlat tool and timelart top modeDaniel Bristot de Oliveira5-0/+697
The rtla timerlat tool is an interface for the timerlat tracer. The timerlat tracer dispatches a kernel thread per-cpu. These threads set a periodic timer to wake themselves up and go back to sleep. After the wakeup, they collect and generate useful information for the debugging of operating system timer latency. The timerlat tracer outputs information in two ways. It periodically prints the timer latency at the timer IRQ handler and the Thread handler. It also provides information for each noise via the osnoise tracepoints. The rtla timerlat top mode displays a summary of the periodic output from the timerlat tracer. Here is one example of the rtla timerlat tool output: ---------- %< ---------- [root@alien ~]# rtla timerlat top -c 0-3 -d 1m Timer Latency 0 00:01:00 | IRQ Timer Latency (us) | Thread Timer Latency (us) CPU COUNT | cur min avg max | cur min avg max 0 #60001 | 0 0 0 3 | 1 1 1 6 1 #60001 | 0 0 0 3 | 2 1 1 5 2 #60001 | 0 0 1 6 | 1 1 2 7 3 #60001 | 0 0 0 7 | 1 1 1 11 ---------- >% ---------- Running: # rtla timerlat --help # rtla timerlat top --help provides information about the available options. Link: https://lkml.kernel.org/r/e95032e20c2b88c962195bf7693bb53c9ebcced8.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13rtla/osnoise: Add the hist modeDaniel Bristot de Oliveira3-1/+807
The rtla osnoise hist tool collects all osnoise:sample_threshold occurrence in a histogram, displaying the results in a user-friendly way. The tool also allows many configurations of the osnoise tracer and the collection of the tracer output. Here is one example of the rtla osnoise hist tool output: ---------- %< ---------- [root@f34 ~]# rtla osnoise hist --bucket-size 10 --entries 100 -c 0-8 -d 1M -r 9000 -P F:1 # RTLA osnoise histogram # Time unit is microseconds (us) # Duration: 0 00:01:00 Index CPU-000 CPU-001 CPU-002 CPU-003 CPU-004 CPU-005 CPU-006 CPU-007 CPU-008 0 430 434 352 455 440 463 467 436 484 10 88 88 92 141 120 100 126 166 100 20 19 7 12 22 8 8 13 13 16 30 6 0 2 0 1 2 2 1 0 50 0 0 0 0 0 0 1 0 0 over: 0 0 0 0 0 0 0 0 0 count: 543 529 458 618 569 573 609 616 600 min: 0 0 0 0 0 0 0 0 0 avg: 0 0 0 0 0 0 0 0 0 max: 30 20 30 20 30 30 50 30 20 ---------- >% ---------- Running - rtla osnoise hist --help provides information about the available options. Link: https://lkml.kernel.org/r/c68060544de89b8b62510ed91c7369f162eb465b.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13rtla/osnoise: Add osnoise top modeDaniel Bristot de Oliveira3-0/+596
The rtla osnoise tool is an interface for the osnoise tracer. The osnoise tracer dispatches a kernel thread per-cpu. These threads read the time in a loop while with preemption, softirqs and IRQs enabled, thus allowing all the sources of osnoise during its execution. The osnoise threads take note of the entry and exit point of any source of interferences, increasing a per-cpu interference counter. The osnoise tracer also saves an interference counter for each source of interference. The rtla osnoise top mode displays information about the periodic summary from the osnoise tracer. One example of rtla osnoise top output is: [root@alien ~]# rtla osnoise top -c 0-3 -d 1m -q -r 900000 -P F:1 Operating System Noise duration: 0 00:01:00 | time is in us CPU Period Runtime Noise % CPU Aval Max Noise Max Single HW NMI IRQ Softirq Thread 0 #58 52200000 1031 99.99802 91 60 0 0 52285 0 101 1 #59 53100000 5 99.99999 5 5 0 9 53122 0 18 2 #59 53100000 7 99.99998 7 7 0 8 53115 0 18 3 #59 53100000 8274 99.98441 277 23 0 9 53778 0 660 "rtla osnoise top --help" works and provide information about the available options. Link: https://lkml.kernel.org/r/0d796993abf587ae5a170bb8415c49368d4999e1.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13rtla: Add osnoise toolDaniel Bristot de Oliveira4-0/+956
The osnoise tool is the interface for the osnoise tracer. The osnoise tool will have multiple "modes" with different outputs. At this point, no mode is included. The osnoise.c includes the osnoise_context abstraction. It serves to read-save-change-restore the default values from tracing/osnoise/ directory. When the context is deleted, the default values are restored. It also includes some other helper functions for managing osnoise tracer sessions. With these bits and pieces in place, we can start adding some functionality to rtla. Link: https://lkml.kernel.org/r/2d44c21ff561f503b4c7b1813892761818118460.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13rtla: Helper functions for rtlaDaniel Bristot de Oliveira4-0/+708
This is a set of utils and tracer helper functions. They are used by rtla mostly to parse config, display data and some trace operations that are not part of libtracefs (because they are only useful it for this case). Link: https://lkml.kernel.org/r/a94c128aba9e6e66d502b7094f2e8c7ac95b12e5.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13rtla: Real-Time Linux Analysis toolDaniel Bristot de Oliveira3-0/+184
The rtla is a meta-tool that includes a set of commands that aims to analyze the real-time properties of Linux. But instead of testing Linux as a black box, rtla leverages kernel tracing capabilities to provide precise information about the properties and root causes of unexpected results. rtla --help works and provide information about the available options. This is just the "main" and the Makefile, no function yet. Link: https://lkml.kernel.org/r/bf9118ed43a09e6c054c9a491cbe7411ad1acd89.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2021-10-25tools/latency-collector: Use correct size when writing queue_full_warningViktor Rosendahl1-1/+1
queue_full_warning is a pointer, so it is wrong to use sizeof to calculate the number of characters of the string it points to. The effect is that we only print out the first few characters of the warning string. The correct way is to use strlen(). We don't need to add 1 to the strlen() because we don't want to write the terminating null character to stdout. Link: https://lkml.kernel.org/r/20211019160701.15587-1-Viktor.Rosendahl@bmw.de Link: https://lore.kernel.org/r/8fd4bb65ef3da67feac9ce3258cdbe9824752cf1.1629198502.git.jing.yangyang@zte.com.cn Link: https://lore.kernel.org/r/20211012025424.180781-1-davidcomponentone@gmail.com Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Viktor Rosendahl <Viktor.Rosendahl@bmw.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-03-18tools/latency-collector: Remove unneeded semicolonXu Wang1-2/+2
Fix semicolon.cocci warning: tools/tracing/latency/latency-collector.c:1021:2-3: Unneeded semicolon Link: https://lkml.kernel.org/r/20210308022459.59881-1-vulab@iscas.ac.cn Reviewed-by: Viktor Rosendahl <Viktor.Rosendahl@bmw.de> Signed-off-by: Xu Wang <vulab@iscas.ac.cn> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-25tracing/tools: fix a couple of spelling mistakesColin Ian King1-3/+3
There is a spelling mistake in the -g help option, I believe it should be "graph". There is also a spelling mistake in a warning message. Fix both mistakes. Link: https://lkml.kernel.org/r/20210225165248.22050-2-Viktor.Rosendahl@bmw.de Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Viktor Rosendahl <Viktor.Rosendahl@bmw.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-12tracing/tools: Add the latency-collector to tools directoryViktor Rosendahl4-0/+2153
This is a tool that is intended to work around the fact that the preemptoff, irqsoff, and preemptirqsoff tracers only work in overwrite mode. The idea is to act randomly in such a way that we do not systematically lose any latencies, so that if enough testing is done, all latencies will be captured. If the same burst of latencies is repeated, then sooner or later we will have captured all the latencies. It also works with the wakeup_dl, wakeup_rt, and wakeup tracers. However, in that case it is probably not useful to use the random sleep functionality. The reason why it may be desirable to catch all latencies with a long test campaign is that for some organizations, it's necessary to test the kernel in the field and not practical for developers to work iteratively with field testers. Because of cost and project schedules it is not possible to start a new test campaign every time a latency problem has been fixed. It uses inotify to detect changes to /sys/kernel/tracing/trace. When a latency is detected, it will either sleep or print immediately, depending on a function that act as an unfair coin toss. If immediate print is chosen, it means that we open /sys/kernel/tracing/trace and thereby cause a blackout period that will hide any subsequent latencies. If sleep is chosen, it means that we wait before opening /sys/kernel/tracing/trace, by default for 1000 ms, to see if there is another latency during this period. If there is, then we will lose the previous latency. The coin will be tossed again with a different probability, and we will either print the new latency, or possibly a subsequent one. The probability for the unfair coin toss is chosen so that there is equal probability to obtain any of the latencies in a burst. However, this assumes that we make an assumption of how many latencies there can be. By default the program assumes that there are no more than 2 latencies in a burst, the probability of immediate printout will be: 1/2 and 1 Thus, the probability of getting each of the two latencies will be 1/2. If we ever find that there is more than one latency in a series, meaning that we reach the probability of 1, then the table will be expanded to: 1/3, 1/2, and 1 Thus, we assume that there are no more than three latencies and each with a probability of 1/3 of being captured. If the probability of 1 is reached in the new table, that is we see more than two closely occurring latencies, then the table will again be extended, and so on. On my systems, it seems like this scheme works fairly well, as long as the latencies we trace are long enough, 300 us seems to be enough. This userspace program receive the inotify event at the end of a latency, and it has time until the end of the next latency to react, that is to open /sys/kernel/tracing/trace. Thus, if we trace latencies that are >300 us, then we have at least 300 us to react. The minimum latency will of course not be 300 us on all systems, it will depend on the hardware, kernel version, workload and configuration. Example usage: In one shell, give the following command: sudo latency-collector -rvv -t preemptirqsoff -s 2000 -a 3 This will trace latencies > 2000us with the preemptirqsoff tracer, using random sleep with maximum verbosity, with a probability table initialized to a size of 3. In another shell, generate a few bursts of latencies: root@host:~# modprobe preemptirq_delay_test delay=3000 test_mode=alternate burst_size=3 root@host:~# echo 1 > /sys/kernel/preemptirq_delay_test/trigger root@host:~# echo 1 > /sys/kernel/preemptirq_delay_test/trigger root@host:~# echo 1 > /sys/kernel/preemptirq_delay_test/trigger root@host:~# echo 1 > /sys/kernel/preemptirq_delay_test/trigger If all goes well, you should be getting stack traces that shows all the different latencies, i.e. you should see all the three functions preemptirqtest_0, preemptirqtest_1, preemptirqtest_2 in the stack traces. Link: https://lkml.kernel.org/r/20210212134421.172750-2-Viktor.Rosendahl@bmw.de Signed-off-by: Viktor Rosendahl <Viktor.Rosendahl@bmw.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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