rtla: Always set all tracer options

rtla currently only sets tracer options that are explicitly set by the
user, with the exception of OSNOISE_WORKLOAD.

This leads to improper behavior in case rtla

rtla: Always set all tracer options

rtla currently only sets tracer options that are explicitly set by the
user, with the exception of OSNOISE_WORKLOAD.

This leads to improper behavior in case rtla is run with those options
not set to the default value. rtla does reset them to the original
value upon exiting, but that does not protect it from starting with
non-default values set either by an improperly exited rtla or by another
user of the tracers.

For example, after running this command:

$ echo 1 > /sys/kernel/tracing/osnoise/stop_tracing_us

all runs of rtla will stop at the 1us threshold, even if not requested
by the user:

$ rtla osnoise hist
Index CPU-000 CPU-001
1 8 5
2 5 9
3 1 2
4 6 1
5 2 1
6 0 1
8 1 1
12 0 1
14 1 0
15 1 0
over: 0 0
count: 25 21
min: 1 1
avg: 3.68 3.05
max: 15 12
rtla osnoise hit stop tracing

Fix the problem by setting the default value for all tracer options if
the user has not provided their own value.

For most of the options, it's enough to just drop the if clause checking
for the value being set. For cpus, "all" is used as the default value,
and for osnoise default period and runtime, default values of
the osnoise_data variable in trace_osnoise.c are used.

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

show more ...

rtla/osnoise: Set OSNOISE_WORKLOAD to true

If running rtla osnoise with NO_OSNOISE_WORKLOAD, it reports no samples:

$ echo NO_OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options
$ rtla osnoise h

rtla/osnoise: Set OSNOISE_WORKLOAD to true

If running rtla osnoise with NO_OSNOISE_WORKLOAD, it reports no samples:

$ echo NO_OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options
$ rtla osnoise hist -d 10s
Index
over: 0
count: 0
min: 0
avg: 0
max: 0

This situation can also happen when running rtla-osnoise after an
improperly exited rtla-timerlat run.

Set OSNOISE_WORKLOAD in rtla-osnoise, too, similarly to what we
already did for timerlat in commit 217f0b1e990e ("rtla/timerlat_top: Set
OSNOISE_WORKLOAD for kernel threads") and commit d8d866171a41
("rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads").

Note that there is no user workload mode for rtla-osnoise yet, so
OSNOISE_WORKLOAD is always set to true.

Cc: Luis Goncalves <[email protected]>
Link: https://lore.kernel.org/[email protected]
Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode")
Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode")
Signed-off-by: Tomas Glozar <[email protected]>
Reviewed-by: John Kacur <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Unify apply_config between top and hist

The functions osnoise_top_apply_config and osnoise_hist_apply_config, as
well as timerlat_top_apply_config and timerlat_hist_apply_config, are
mostly th

rtla: Unify apply_config between top and hist

The functions osnoise_top_apply_config and osnoise_hist_apply_config, as
well as timerlat_top_apply_config and timerlat_hist_apply_config, are
mostly the same.

Move common part from them into separate functions osnoise_apply_config
and timerlat_apply_config.

For rtla-timerlat, also unify params->user_hist and params->user_top
into one field called params->user_data, and move several fields used
only by timerlat-top into the top-only section of struct
timerlat_params.

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

show more ...

rtla/osnoise: Unify params struct

Instead of having separate structs osnoise_top_params and
osnoise_hist_params, use one struct osnoise_params for both.

This allows code using the structs to be sha

rtla/osnoise: Unify params struct

Instead of having separate structs osnoise_top_params and
osnoise_hist_params, use one struct osnoise_params for both.

This allows code using the structs to be shared between osnoise-top and
osnoise-hist.

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

show more ...

rtla: Fix segfault in save_trace_to_file call

Running rtla with exit on threshold, but without saving trace leads to a
segmenetation fault:

$ rtla timerlat hist -T 10
...
Max timerlat IRQ latency f

rtla: Fix segfault in save_trace_to_file call

Running rtla with exit on threshold, but without saving trace leads to a
segmenetation fault:

$ rtla timerlat hist -T 10
...
Max timerlat IRQ latency from idle: 4.29 us in cpu 0
Segmentation fault

This is caused by null pointer deference in the call of
save_trace_to_file, which attempts to dereference an uninitialized
osnoise_tool variable:

save_trace_to_file(record->trace.inst, params->trace_output);
^ this is uninitialized if params->trace_output is
not set

Fix this by not attempting to dereference "record" if it is NULL and
passing NULL instead. As a safety measure, the first field is also
checked for NULL inside save_trace_to_file.

Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Costa Shulyupin <[email protected]>
Link: https://lore.kernel.org/[email protected]
Fixes: dc4d4e7c72d1 ("rtla: Refactor save_trace_to_file")
Signed-off-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Refactor save_trace_to_file

The functions osnoise_hist_main(), osnoise_top_main(),
timerlat_hist_main(), and timerlat_top_main() are lengthy and contain
duplicated code.

Refactor by consolida

rtla: Refactor save_trace_to_file

The functions osnoise_hist_main(), osnoise_top_main(),
timerlat_hist_main(), and timerlat_top_main() are lengthy and contain
duplicated code.

Refactor by consolidating the duplicate lines into the
save_trace_to_file() function.

Cc: Daniel Bristot de Oliveira <[email protected]>
Cc: John Kacur <[email protected]>
Cc: "Luis Claudio R. Goncalves" <[email protected]>
Cc: Eder Zulian <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: Gabriele Monaco <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Costa Shulyupin <[email protected]>
Reviewed-by: Tomas Glozar <[email protected]>
Tested-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla/timerlat_top: Use BPF to collect samples

Collect samples using BPF program instead of pulling them from tracefs.

If the osnoise:timerlat_sample tracepoint is unavailable or the BPF
program fai

rtla/timerlat_top: Use BPF to collect samples

Collect samples using BPF program instead of pulling them from tracefs.

If the osnoise:timerlat_sample tracepoint is unavailable or the BPF
program fails to load for whatever reason, rtla falls back to the old
implementation.

The collection of samples using the BPF program is fully self-contained
and requires no activity of the userspace part of rtla during the
measurement. Thus, rtla only pulls the summary from the BPF map and
displays it every second, improving the performance.

In --aa-only mode, the BPF program does not collect any data and only
signalizes the end of tracing to userspace. An optimization that re-used
the main trace instance for auto-analysis in aa-only mode was dropped, as
rtla no longer turns tracing on in the main trace instance, making it
useless for auto-analysis.

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/timerlat_top: Move divisor to update

Unlike timerlat-hist, timerlat-top applies the output divisor used to
set ns/us mode when printing results instead of applying it when
collecting the sample

rtla/timerlat_top: Move divisor to update

Unlike timerlat-hist, timerlat-top applies the output divisor used to
set ns/us mode when printing results instead of applying it when
collecting the samples.

Move the application of the divisor from timerlat_top_print into
timerlat_top_update to make it consistent with timerlat-hist.

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/timerlat_hist: Use BPF to collect samples

Collect samples using BPF program instead of pulling them from tracefs.

If the osnoise:timerlat_sample tracepoint is unavailable or the BPF
program fa

rtla/timerlat_hist: Use BPF to collect samples

Collect samples using BPF program instead of pulling them from tracefs.

If the osnoise:timerlat_sample tracepoint is unavailable or the BPF
program fails to load for whatever reason, rtla falls back to the old
implementation.

The collection of samples using the BPF program is fully self-contained
and requires no activity of the userspace part of rtla during the
measurement. Thus, instead of waking up every second to collect samples,
rtla simply sleeps until woken up by a signal or threshold overflow.

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/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/timerlat: Unify params struct

Instead of having separate structs timerlat_top_params and
timerlat_hist_params, use one struct timerlat_params for both.

This allows code using the structs to be

rtla/timerlat: Unify params struct

Instead of having separate structs timerlat_top_params and
timerlat_hist_params, use one struct timerlat_params for both.

This allows code using the structs to be shared between timerlat-top and
timerlat-hist.

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: Report missed event count

Print how many events were missed by trace buffer overflow in the main
instance at the end of the run (for hist) or during the run (for top).

Cc: John Kacur <jkacur@

rtla: Report missed event count

Print how many events were missed by trace buffer overflow in the main
instance at the end of the run (for hist) or during the run (for top).

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

show more ...

rtla: Add function to report missed events

Add osnoise_report_missed_events to be used to report the number
of missed events either during or after an osnoise or timerlat run.
Also, display the perc

rtla: Add function to report missed events

Add osnoise_report_missed_events to be used to report the number
of missed events either during or after an osnoise or timerlat run.
Also, display the percentage of missed events compared to the total
number of received events.

If an unknown number of missed events was reported during the run, the
entire number of missed events is reported as unknown.

Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Gabriele Monaco <[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: Count all processed events

Add a field processed_events to struct trace_instance and increment it
in collect_registered_events, regardless of whether a handler is
registered for the event.

Th

rtla: Count all processed events

Add a field processed_events to struct trace_instance and increment it
in collect_registered_events, regardless of whether a handler is
registered for the event.

The purpose is to calculate the percentage of events that were missed
due to tracefs buffer overflow.

Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Gabriele Monaco <[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: Count missed trace events

Add function collect_missed_events to trace.c to act as a callback for
tracefs_follow_missed_events, summing the number of total missed events
into a new field missin

rtla: Count missed trace events

Add function collect_missed_events to trace.c to act as a callback for
tracefs_follow_missed_events, summing the number of total missed events
into a new field missing_events of struct trace_instance.

In case record->missed_events is negative, trace->missed_events is set
to UINT64_MAX to signify an unknown number of events was missed.

The callback is activated on initialization of the trace instance.

Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Gabriele Monaco <[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/rtla: Add osnoise_trace_is_off()

All of the users of trace_is_off() passes in &record->trace as the second
parameter, where record is a pointer to a struct osnoise_tool. This record
could be N

tools/rtla: Add osnoise_trace_is_off()

All of the users of trace_is_off() passes in &record->trace as the second
parameter, where record is a pointer to a struct osnoise_tool. This record
could be NULL and there is a hidden dependency that the trace field is the
first field to allow &record->trace to work with a NULL record pointer.

In order to make this code a bit more robust, as record shouldn't be
dereferenced if it is NULL, even if the code does work, create a new
function called osnoise_trace_is_off() that takes the pointer to a
struct osnoise_tool as its second parameter. This way it can properly test
if it is NULL before it dereferences it.

The old function trace_is_off() is removed and the function
osnoise_trace_is_off() is added into osnoise.c which is what the
struct osnoise_tool is associated with.

Cc: John Kacur <[email protected]>
Cc: "Luis Claudio R. Goncalves" <[email protected]>
Cc: Eder Zulian <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: Tomas Glozar <[email protected]>
Cc: Gabriele Monaco <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Costa Shulyupin <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads

When using rtla timerlat with userspace threads (-u or -U), rtla
disables the OSNOISE_WORKLOAD option in
/sys/kernel/tracing/osnoise/option

rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads

When using rtla timerlat with userspace threads (-u or -U), rtla
disables the OSNOISE_WORKLOAD option in
/sys/kernel/tracing/osnoise/options. This option is not re-enabled in a
subsequent run with kernel-space threads, leading to rtla collecting no
results if the previous run exited abnormally:

$ rtla timerlat top -u
^\Quit (core dumped)
$ rtla timerlat top -k -d 1s
Timer Latency
0 00:00:01 | IRQ Timer Latency (us) | Thread Timer Latency (us)
CPU COUNT | cur min avg max | cur min avg max

The issue persists until OSNOISE_WORKLOAD is set manually by running:
$ echo OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options

Set OSNOISE_WORKLOAD when running rtla with kernel-space threads if
available to fix the issue.

Cc: [email protected]
Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Link: https://lore.kernel.org/[email protected]
Fixes: cdca4f4e5e8e ("rtla/timerlat_top: Add timerlat user-space support")
Signed-off-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads

When using rtla timerlat with userspace threads (-u or -U), rtla
disables the OSNOISE_WORKLOAD option in
/sys/kernel/tracing/osnoise/optio

rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads

When using rtla timerlat with userspace threads (-u or -U), rtla
disables the OSNOISE_WORKLOAD option in
/sys/kernel/tracing/osnoise/options. This option is not re-enabled in a
subsequent run with kernel-space threads, leading to rtla collecting no
results if the previous run exited abnormally:

$ rtla timerlat hist -u
^\Quit (core dumped)
$ rtla timerlat hist -k -d 1s
Index
over:
count:
min:
avg:
max:
ALL: IRQ Thr Usr
count: 0 0 0
min: - - -
avg: - - -
max: - - -

The issue persists until OSNOISE_WORKLOAD is set manually by running:
$ echo OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options

Set OSNOISE_WORKLOAD when running rtla with kernel-space threads if
available to fix the issue.

Cc: [email protected]
Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Link: https://lore.kernel.org/[email protected]
Fixes: ed774f7481fa ("rtla/timerlat_hist: Add timerlat user-space support")
Signed-off-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla/osnoise: Distinguish missing workload option

osnoise_set_workload returns -1 for both missing OSNOISE_WORKLOAD option
and failure in setting the option.

Return -1 for missing and -2 for failur

rtla/osnoise: Distinguish missing workload option

osnoise_set_workload returns -1 for both missing OSNOISE_WORKLOAD option
and failure in setting the option.

Return -1 for missing and -2 for failure to distinguish them.

Cc: [email protected]
Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[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/timerlat_top: Abort event processing on second signal

If either SIGINT is received twice, or after a SIGALRM (that is, after
timerlat was supposed to stop), abort processing events currently le

rtla/timerlat_top: Abort event processing on second signal

If either SIGINT is received twice, or after a SIGALRM (that is, after
timerlat was supposed to stop), abort processing events currently left
in the tracefs buffer and exit immediately.

This allows the user to exit rtla without waiting for processing all
events, should that take longer than wanted, at the cost of not
processing all samples.

Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Gabriele Monaco <[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/timerlat_hist: Abort event processing on second signal

If either SIGINT is received twice, or after a SIGALRM (that is, after
timerlat was supposed to stop), abort processing events currently l

rtla/timerlat_hist: Abort event processing on second signal

If either SIGINT is received twice, or after a SIGALRM (that is, after
timerlat was supposed to stop), abort processing events currently left
in the tracefs buffer and exit immediately.

This allows the user to exit rtla without waiting for processing all
events, should that take longer than wanted, at the cost of not
processing all samples.

Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Gabriele Monaco <[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/timerlat_top: Stop timerlat tracer on signal

Currently, when either SIGINT from the user or SIGALRM from the duration
timer is caught by rtla-timerlat, stop_tracing is set to break out of
the m

rtla/timerlat_top: Stop timerlat tracer on signal

Currently, when either SIGINT from the user or SIGALRM from the duration
timer is caught by rtla-timerlat, stop_tracing is set to break out of
the main loop. This is not sufficient for cases where the timerlat
tracer is producing more data than rtla can consume, since in that case,
rtla is looping indefinitely inside tracefs_iterate_raw_events, never
reaches the check of stop_tracing and hangs.

In addition to setting stop_tracing, also stop the timerlat tracer on
received signal (SIGINT or SIGALRM). This will stop new samples so that
the existing samples may be processed and tracefs_iterate_raw_events
eventually exits.

Cc: [email protected]
Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Gabriele Monaco <[email protected]>
Link: https://lore.kernel.org/[email protected]
Fixes: a828cd18bc4a ("rtla: Add timerlat tool and timelart top mode")
Signed-off-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla/timerlat_hist: Stop timerlat tracer on signal

Currently, when either SIGINT from the user or SIGALRM from the duration
timer is caught by rtla-timerlat, stop_tracing is set to break out of
the

rtla/timerlat_hist: Stop timerlat tracer on signal

Currently, when either SIGINT from the user or SIGALRM from the duration
timer is caught by rtla-timerlat, stop_tracing is set to break out of
the main loop. This is not sufficient for cases where the timerlat
tracer is producing more data than rtla can consume, since in that case,
rtla is looping indefinitely inside tracefs_iterate_raw_events, never
reaches the check of stop_tracing and hangs.

In addition to setting stop_tracing, also stop the timerlat tracer on
received signal (SIGINT or SIGALRM). This will stop new samples so that
the existing samples may be processed and tracefs_iterate_raw_events
eventually exits.

Cc: [email protected]
Cc: John Kacur <[email protected]>
Cc: Luis Goncalves <[email protected]>
Cc: Gabriele Monaco <[email protected]>
Link: https://lore.kernel.org/[email protected]
Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode")
Signed-off-by: Tomas Glozar <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...

rtla: Add trace_instance_stop

Support not only turning trace on for the timerlat tracer, but also
turning it off.

This will be used in subsequent patches to stop the timerlat tracer
without also wi

rtla: Add trace_instance_stop

Support not only turning trace on for the timerlat tracer, but also
turning it off.

This will be used in subsequent patches to stop the timerlat tracer
without also wiping the trace buffer.

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

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