tools/build: Use SYSTEM_BPFTOOL for system bpftool

The feature test for system bpftool uses BPFTOOL as the variable to set
its path, defaulting to just "bpftool" if not set by the user.

This confli

tools/build: Use SYSTEM_BPFTOOL for system bpftool

The feature test for system bpftool uses BPFTOOL as the variable to set
its path, defaulting to just "bpftool" if not set by the user.

This conflicts with selftests and a few other utilities, which expect
BPFTOOL to be set to the in-tree bpftool path by default. For example,
bpftool selftests fail to build:

$ make -C tools/testing/selftests/bpf/
make: Entering directory '/home/tglozar/dev/linux/tools/testing/selftests/bpf'

make: *** No rule to make target 'bpftool', needed by '/home/tglozar/dev/linux/tools/testing/selftests/bpf/tools/include/vmlinux.h'. Stop.
make: Leaving directory '/home/tglozar/dev/linux/tools/testing/selftests/bpf'

Fix the problem by renaming the variable used for system bpftool from
BPFTOOL to SYSTEM_BPFTOOL, so that the new usage does not conflict with
the existing one of BPFTOOL.

Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Link: https://lore.kernel.org/[email protected]
Fixes: 8a635c3856dd ("tools/build: Add bpftool-skeletons feature test")
Closes: https://lore.kernel.org/linux-kernel/[email protected]/
Reported-by: Venkat Rao Bagalkote <[email protected]>
Tested-by: Venkat Rao Bagalkote <[email protected]>
Suggested-by: Quentin Monnet <[email protected]>
Acked-by: Quentin Monnet <[email protected]>
Signed-off-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla/timerlat: Add BPF skeleton to collect samples

Add BPF program that attaches to the osnoise:timerlat_sample tracepoint
and collects both the summary and the histogram (if requested) into BPF
map

rtla/timerlat: Add BPF skeleton to collect samples

Add BPF program that attaches to the osnoise:timerlat_sample tracepoint
and collects both the summary and the histogram (if requested) into BPF
maps (one map of each kind per context).

The program is designed to be used for both timerlat-top and
timerlat-hist. If using with timerlat-top, the "entries" parameter is
set to zero, which prevents the BPF program from recording histogram
entries. In that case, the maps for histograms do not have to be
created, as the BPF verifier will identify the code using them as
unreachable.

An IRQ or thread latency threshold might be supplied to stop recording
if hit, similar to the timerlat tracer threshold, which stops ftrace
tracing if hit. A BPF ringbuffer is used to signal threshold overflow to
userspace. In aa-only mode, this is the only function of the BPF
program.

Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Gabriele Monaco <[email protected]>
Cc: Clark Williams <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Add optional dependency on BPF tooling

If tooling required for building BPF CO-RE skeletons is present (that
is, libbpf, clang with BPF CO-RE support, and bpftool), turn on
HAVE_BPF_SKEL flag.

rtla: Add optional dependency on BPF tooling

If tooling required for building BPF CO-RE skeletons is present (that
is, libbpf, clang with BPF CO-RE support, and bpftool), turn on
HAVE_BPF_SKEL flag.

Those requirements are similar to what perf requires, with the
difference of using system libbpf and bpftool instead of in-tree
versions.

rtla can be forcefully built without BPF skeleton support by setting
BUILD_BPF_SKEL=0 manually; in that case, a warning is displayed.

Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Gabriele Monaco <[email protected]>
Cc: Clark Williams <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

tools: Remove redundant quiet setup

Q is exported from Makefile.include so it is not necessary to manually
set it.

Reviewed-by: Jiri Olsa <[email protected]>
Signed-off-by: Charlie Jenkins <charlie@

tools: Remove redundant quiet setup

Q is exported from Makefile.include so it is not necessary to manually
set it.

Reviewed-by: Jiri Olsa <[email protected]>
Signed-off-by: Charlie Jenkins <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
Acked-by: Quentin Monnet <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Benjamin Tissoires <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Daniel Lezcano <[email protected]>
Cc: Eduard Zingerman <[email protected]>
Cc: Hao Luo <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: John Fastabend <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: KP Singh <[email protected]>
Cc: Lukasz Luba <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: Mykola Lysenko <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Stanislav Fomichev <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Cc: Yonghong Song <[email protected]>
Cc: Zhang Rui <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

show more ...

tools/rtla: Add basic test suite

Implement a simple TAP-based test engine in bash and a few basic tests
using it, to be used to check for bugs and regressions.

A new "check" target is added to the

tools/rtla: Add basic test suite

Implement a simple TAP-based test engine in bash and a few basic tests
using it, to be used to check for bugs and regressions.

A new "check" target is added to the rtla Makefile that runs the test suite
using the "prove" command implemented by Test::Harness.

The only test format currently supported is running rtla with defined
command arguments per test, checking its exit code. In case the exit
code is non-zero, the output of rtla is displayed, together with the
exit code.

The test cases are adopted from rtla tests in the Continuous Kernel
Integration (CKI) project [1] with the authors' approval.

[1] https://gitlab.com/redhat/centos-stream/tests/kernel/kernel-tests/-/blob/main/rt-tests/us/rtla/

Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Chang Yin <[email protected]>
Cc: Qiao Zhao <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Add optional dependency on libcpupower

If libcpupower is present, set HAVE_LIBCPUPOWER_SUPPORT macro to allow
features depending on libcpupower in rtla.

Link: https://lore.kernel.org/20241017

rtla: Add optional dependency on libcpupower

If libcpupower is present, set HAVE_LIBCPUPOWER_SUPPORT macro to allow
features depending on libcpupower in rtla.

Link: https://lore.kernel.org/[email protected]
Signed-off-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

tools/rtla: Use tools/build makefiles to build rtla

Use tools/build/ makefiles to build rtla, inheriting the benefits of
it. For example, having a proper way to handle dependencies.

rtla is built u

tools/rtla: Use tools/build makefiles to build rtla

Use tools/build/ makefiles to build rtla, inheriting the benefits of
it. For example, having a proper way to handle dependencies.

rtla is built using perf infra-structure when building inside the
kernel tree.

At this point, rtla diverges from perf in two points: Documentation
and tarball generation/build.

At the documentation level, rtla is one step ahead, placing the
documentation at Documentation/tools/rtla/, using the same build
tools as kernel documentation. The idea is to move perf
documentation to the same scheme and then share the same makefiles.

rtla has a tarball target that the (old) RHEL8 uses. The tarball was
kept using a simple standalone makefile for compatibility. The
standalone makefile shares most of the code, e.g., flags, with
regular buildings.

The tarball method was set as deprecated. If necessary, we can make
a rtla tarball like perf, which includes the entire tools/build.
But this would also require changes in the user side (the directory
structure changes, and probably the deps to build the package).

Inspired on perf and objtool.

Link: https://lkml.kernel.org/r/57563abf2715d22515c0c54a87cff3849eca5d52.1710519524.git.bristot@kernel.org

Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: John Kacur <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Jiri Olsa <[email protected]>
Suggested-by: Linus Torvalds <[email protected]>
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>

show more ...

tools/rtla: Fix Makefile compiler options for clang

The following errors are showing up when compiling rtla with clang:

$ make HOSTCC=clang CC=clang LLVM_IAS=1
[...]

clang -O -g -DVERSION=\"6.

tools/rtla: Fix Makefile compiler options for clang

The following errors are showing up when compiling rtla with clang:

$ make HOSTCC=clang CC=clang LLVM_IAS=1
[...]

clang -O -g -DVERSION=\"6.8.0-rc1\" -flto=auto -ffat-lto-objects
-fexceptions -fstack-protector-strong
-fasynchronous-unwind-tables -fstack-clash-protection -Wall
-Werror=format-security -Wp,-D_FORTIFY_SOURCE=2
-Wp,-D_GLIBCXX_ASSERTIONS -Wno-maybe-uninitialized
$(pkg-config --cflags libtracefs) -c -o src/utils.o src/utils.c

clang: warning: optimization flag '-ffat-lto-objects' is not supported [-Wignored-optimization-argument]
warning: unknown warning option '-Wno-maybe-uninitialized'; did you mean '-Wno-uninitialized'? [-Wunknown-warning-option]
1 warning generated.

clang -o rtla -ggdb src/osnoise.o src/osnoise_hist.o src/osnoise_top.o
src/rtla.o src/timerlat_aa.o src/timerlat.o src/timerlat_hist.o
src/timerlat_top.o src/timerlat_u.o src/trace.o src/utils.o $(pkg-config --libs libtracefs)

src/osnoise.o: file not recognized: file format not recognized
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [Makefile:110: rtla] Error 1

Solve these issues by:
- removing -ffat-lto-objects and -Wno-maybe-uninitialized if using clang
- informing the linker about -flto=auto

Link: https://lore.kernel.org/linux-trace-kernel/567ac1b94effc228ce9a0225b9df7232a9b35b55.1707217097.git.bristot@kernel.org

Cc: [email protected]
Cc: Masami Hiramatsu <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Bill Wendling <[email protected]>
Cc: Justin Stitt <[email protected]>
Fixes: 1a7b22ab15eb ("tools/rtla: Build with EXTRA_{C,LD}FLAGS")
Suggested-by: Donald Zickus <[email protected]>
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>

show more ...

rtla: Add hwnoise tool

The hwnoise tool is a special mode for the osnoise top tool.

hwnoise dispatches the osnoise tracer and displays a summary of the noise.
The difference is that it runs the tra

rtla: Add hwnoise tool

The hwnoise tool is a special mode for the osnoise top tool.

hwnoise dispatches the osnoise tracer and displays a summary of the noise.
The difference is that it runs the tracer with the OSNOISE_IRQ_DISABLE
option set, thus only allowing only hardware-related noise, resulting in
a simplified output. hwnoise has the same features of osnoise.

An example of the tool's output:

# rtla hwnoise -c 1-11 -T 1 -d 10m -q
Hardware-related Noise
duration: 0 00:10:00 | time is in us
CPU Period Runtime Noise % CPU Aval Max Noise Max Single HW NMI
1 #599 599000000 138 99.99997 3 3 4 74
2 #599 599000000 85 99.99998 3 3 4 75
3 #599 599000000 86 99.99998 4 3 6 75
4 #599 599000000 81 99.99998 4 4 2 75
5 #599 599000000 85 99.99998 2 2 2 75

Link: https://lkml.kernel.org/r/2d6f49a6f3a4f8b51b2c806458b1cff71ad4d014.1675805361.git.bristot@kernel.org

Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Cc: Daniel Bristot de Oliveira <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Clark Williams <[email protected]>
Cc: Bagas Sanjaya <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Consolidate and show all necessary libraries that failed for building

When building rtla tools, if the necessary libraries are not installed
(libtraceevent and libtracefs), show the ones that

rtla: Consolidate and show all necessary libraries that failed for building

When building rtla tools, if the necessary libraries are not installed
(libtraceevent and libtracefs), show the ones that are missing in one
consolidated output, and also show how to install them (at least for
Fedora).

Link: https://lore.kernel.org/all/CAHk-=wh+e1qcCnEYJ3JRDVLNCYbJ=0u+Ts5bOYZnY3mX_k-hFA@mail.gmail.com/
Link: https://lkml.kernel.org/r/[email protected]

Suggested-by: Linus Torvalds <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

tools/rtla: Build with EXTRA_{C,LD}FLAGS

To allow for distributions and other builders to apply hardening
policy and other customisation, append EXTRA_CFLAGS and EXTRA_LDFLAGS
to the corresponding v

tools/rtla: Build with EXTRA_{C,LD}FLAGS

To allow for distributions and other builders to apply hardening
policy and other customisation, append EXTRA_CFLAGS and EXTRA_LDFLAGS
to the corresponding variables.

Link: https://lore.kernel.org/linux-trace-devel/[email protected]

Signed-off-by: Ben Hutchings <[email protected]>
Acked-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

tools/rtla: Fix command symlinks

"ln -s" stores the next argument directly as the symlink target, so
it needs to be a relative path. In this case, just "rtla".

Link: https://lore.kernel.org/linux-

tools/rtla: Fix command symlinks

"ln -s" stores the next argument directly as the symlink target, so
it needs to be a relative path. In this case, just "rtla".

Link: https://lore.kernel.org/linux-trace-devel/[email protected]

Fixes: 0605bf009f18 ("rtla: Add osnoise tool")
Fixes: a828cd18bc4a ("rtla: Add timerlat tool and timelart top mode")
Signed-off-by: Ben Hutchings <[email protected]>
Acked-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Fix Makefile when called from -C tools/

Sedat Dilek reported an error on rtla Makefile when running:

$ make -C tools/ clean
[...]
make[2]: Entering directory
'/home/dileks/src

rtla: Fix Makefile when called from -C tools/

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 <[email protected]>
Tested-by: Sedat Dilek <[email protected]>
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Remove procps-ng dependency

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 pie

rtla: Remove procps-ng dependency

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 <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Tao Zhou <[email protected]>
Fixes: b1696371d865 ("rtla: Helper functions for rtla")
Reported-by: Daniel Wagner <[email protected]>
Reviewed-by: Daniel Wagner <[email protected]>
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Don't overwrite existing directory mode

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 exis

rtla: Don't overwrite existing directory mode

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/[email protected]

Cc: Daniel Bristot de Oliveria <[email protected]>
Fixes: 79ce8f43ac5a ("rtla: Real-Time Linux Analysis tool")
Acked-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: John Kacur <[email protected]>
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla/Makefile: Properly handle dependencies

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 t

rtla/Makefile: Properly handle dependencies

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 <[email protected]>
Cc: Andrew Morton <[email protected]>
Reported-by: Linus Torvalds <[email protected]>
Suggested-by: Steven Rostedt <[email protected]>
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

kbuild: replace $(if A,A,B) with $(or A,B)

$(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 a

kbuild: replace $(if A,A,B) with $(or A,B)

$(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 <[email protected]>
Reviewed-by: Nicolas Schier <[email protected]>

show more ...

rtla: Follow kernel version

To avoid having commits with new version, it is just easier to follow
kernel version.

Link: https://lkml.kernel.org/r/9c2df0d1de65cea96c7d731fe64781a2bb90c5b3.1643990447

rtla: Follow kernel version

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 <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Make doc build optional

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.

rtla: Make doc build optional

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/[email protected]

Acked-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Add Documentation

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: Add Documentation

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 <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Clark Williams <[email protected]>
Cc: John Kacur <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Daniel Bristot de Oliveira <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Suggested-by: Steven Rostedt <[email protected]>
Suggested-by: Jonathan Corbet <[email protected]>
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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rtla: Add timerlat tool and timelart top mode

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 tim

rtla: Add timerlat tool and timelart top mode

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 <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Clark Williams <[email protected]>
Cc: John Kacur <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Daniel Bristot de Oliveira <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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rtla: Add osnoise tool

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.

rtla: Add osnoise tool

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 <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Clark Williams <[email protected]>
Cc: John Kacur <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Daniel Bristot de Oliveira <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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rtla: Real-Time Linux Analysis tool

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

rtla: Real-Time Linux Analysis tool

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 <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Clark Williams <[email protected]>
Cc: John Kacur <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Daniel Bristot de Oliveira <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

show more ...