rtla: Allow unsetting non-list custom-callback CLI options

libsubcmd implicitly allows the user to unset already set options using
a "no-" prefix for long options. For example, if I set the period like
this:

$ rtla timerlat -D
Loading BPF program
reading osnoise/timerlat_period_us returned 1000
setting osnoise/timerlat_period_us to 1000
reading osnoise/print_stack returned 0
setting osnoise/print_stack to 0
...
<timerlat top>

it can be unset by a subsequent --no-debug:

$ rtla timerlat -D --no-debug
...
<timerlat top>

Currently, this works only for boolean options. Extend the feature for
all options by implementing handling of the "unset" argument in opt_*()
callbacks defined in cli_p.h, except for list options, i.e. options that
can be passed multiple times (--event, --filter, --trigger,
--on-threshold, --on-end).

This allows, for example, unsetting of int/long long options, e.g. "-p":

$ rtla timerlat -D -p100 --no-period
...
setting osnoise/timerlat_period_us to 1000
...

By default, options in params struct are reset to zero. A constant is
added for every parameter with a different default value, which is then
used both in <tool>_hist_args() while setting the initial value and in
opt_*() when unsetting the option. This refactoring ensures there is no
duplicate "magic number".

The default value for opt_llong_callback() and opt_int_callback() is
passed in struct option's defval field; new macros
RTLA_OPT_{LLONG,INT}{,_DEFVAL} are added to define the field
conveniently. The default value for other callbacks is hardcoded inside
each callback's unset logic.

Reviewed-by: Wander Lairson Costa <wander@redhat.com>
Link: https://lore.kernel.org/r/20260629083654.1548925-1-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
This commit is contained in:
Tomas Glozar 2026-06-29 10:36:51 +02:00
parent 075b74841b
commit deaec85cd8
2 changed files with 194 additions and 67 deletions

View File

@ -192,10 +192,10 @@ struct common_params *osnoise_hist_parse_args(int argc, char **argv)
actions_init(&params->common.threshold_actions);
actions_init(&params->common.end_actions);
/* display data in microseconds */
params->common.output_divisor = 1000;
params->common.hist.bucket_size = 1;
params->common.hist.entries = 256;
/* set default values */
params->common.output_divisor = default_output_divisor;
params->common.hist.bucket_size = default_bucket_size;
params->common.hist.entries = default_entries;
argc = parse_options(argc, (const char **)argv,
osnoise_hist_options, osnoise_hist_usage,
@ -280,19 +280,15 @@ struct common_params *timerlat_top_parse_args(int argc, char **argv)
actions_init(&params->common.threshold_actions);
actions_init(&params->common.end_actions);
/* disabled by default */
params->dma_latency = -1;
params->deepest_idle_state = -2;
/* display data in microseconds */
params->common.output_divisor = 1000;
/* set default values */
params->dma_latency = default_dma_latency;
params->deepest_idle_state = default_deepest_idle_state;
params->common.output_divisor = default_output_divisor;
params->stack_format = default_stack_format;
/* default to BPF mode */
params->mode = TRACING_MODE_BPF;
/* default to truncate stack format */
params->stack_format = STACK_FORMAT_TRUNCATE;
argc = parse_options(argc, (const char **)argv,
timerlat_top_options, timerlat_top_usage,
common_parse_options_flags);
@ -403,23 +399,17 @@ struct common_params *timerlat_hist_parse_args(int argc, char **argv)
actions_init(&params->common.threshold_actions);
actions_init(&params->common.end_actions);
/* disabled by default */
params->dma_latency = -1;
/* disabled by default */
params->deepest_idle_state = -2;
/* display data in microseconds */
params->common.output_divisor = 1000;
params->common.hist.bucket_size = 1;
params->common.hist.entries = 256;
/* set default values */
params->dma_latency = default_dma_latency;
params->deepest_idle_state = default_deepest_idle_state;
params->common.output_divisor = default_output_divisor;
params->common.hist.bucket_size = default_bucket_size;
params->common.hist.entries = default_entries;
params->stack_format = default_stack_format;
/* default to BPF mode */
params->mode = TRACING_MODE_BPF;
/* default to truncate stack format */
params->stack_format = STACK_FORMAT_TRUNCATE;
argc = parse_options(argc, (const char **)argv,
timerlat_hist_options, timerlat_hist_usage,
common_parse_options_flags);

View File

@ -22,6 +22,38 @@ struct timerlat_cb_data {
char *trace_output;
};
/*
* Non-zero default values for parameters
*/
static const int default_dma_latency = -1; /* -1 = unset */
static const int default_deepest_idle_state = -2; /* -1 = disable all, -2 = unset */
static const int default_output_divisor = 1000;
static const int default_bucket_size = 1;
static const int default_entries = 256;
static const enum stack_format default_stack_format = STACK_FORMAT_TRUNCATE;
/*
* Shorthand macros for integer/long long command line options using
* opt_int_callback/opt_llong_callback, with variants that set defval.
*
* Note: defval's type is intptr_t. opt_int_callback interprets it directly as
* an int, opt_llong_callback interprets it as a pointer to a long long, as
* long long does not fit into intptr_t on 32-bit architectures.
*/
#define RTLA_OPT_LLONG(s, l, v, a, h) \
OPT_CALLBACK(s, l, v, a, h, opt_llong_callback)
#define RTLA_OPT_LLONG_DEFVAL(s, l, v, a, h, d) { .type = OPTION_CALLBACK, \
.short_name = (s), .long_name = (l), .value = (v), .argh = (a), \
.help = (h), .callback = opt_llong_callback, .defval = (intptr_t)(d) }
#define RTLA_OPT_INT(s, l, v, a, h) \
OPT_CALLBACK(s, l, v, a, h, opt_int_callback)
#define RTLA_OPT_INT_DEFVAL(s, l, v, a, h, d) { .type = OPTION_CALLBACK, \
.short_name = (s), .long_name = (l), .value = (v), .argh = (a), \
.help = (h), .callback = opt_int_callback, .defval = (intptr_t)(d) }
/*
* Macros for command line options common to all tools
*
@ -108,14 +140,12 @@ struct timerlat_cb_data {
#define RTLA_OPT_QUIET OPT_BOOLEAN('q', "quiet", &params->common.quiet, \
"print only a summary at the end")
#define RTLA_OPT_TRACE_BUFFER_SIZE OPT_CALLBACK(0, "trace-buffer-size", \
#define RTLA_OPT_TRACE_BUFFER_SIZE RTLA_OPT_INT(0, "trace-buffer-size", \
&params->common.buffer_size, "kB", \
"set the per-cpu trace buffer size in kB", \
opt_int_callback)
"set the per-cpu trace buffer size in kB")
#define RTLA_OPT_WARM_UP OPT_CALLBACK(0, "warm-up", &params->common.warmup, "s", \
"let the workload run for s seconds before collecting data", \
opt_int_callback)
#define RTLA_OPT_WARM_UP RTLA_OPT_INT(0, "warm-up", &params->common.warmup, "s", \
"let the workload run for s seconds before collecting data")
#define RTLA_OPT_AUTO(cb) OPT_CALLBACK('a', "auto", &cb_data, "us", \
"set automatic trace mode, stopping the session if argument in us sample is hit", \
@ -143,7 +173,12 @@ static int opt_llong_callback(const struct option *opt, const char *arg, int uns
{
long long *value = opt->value;
if (unset || !arg)
if (unset) {
*value = opt->defval ? *(long long *)opt->defval : 0;
return 0;
}
if (!arg)
return -1;
*value = get_llong_from_str((char *)arg);
@ -154,7 +189,12 @@ static int opt_int_callback(const struct option *opt, const char *arg, int unset
{
int *value = opt->value;
if (unset || !arg)
if (unset) {
*value = (int)opt->defval;
return 0;
}
if (!arg)
return -1;
if (strtoi(arg, value))
@ -168,7 +208,13 @@ static int opt_cpus_cb(const struct option *opt, const char *arg, int unset)
struct common_params *params = opt->value;
int retval;
if (unset || !arg)
if (unset) {
CPU_ZERO(&params->monitored_cpus);
params->cpus = NULL;
return 0;
}
if (!arg)
return -1;
retval = parse_cpu_set((char *)arg, &params->monitored_cpus);
@ -183,8 +229,11 @@ static int opt_cgroup_cb(const struct option *opt, const char *arg, int unset)
{
struct common_params *params = opt->value;
if (unset)
return -1;
if (unset) {
params->cgroup = 0;
params->cgroup_name = NULL;
return 0;
}
params->cgroup = 1;
params->cgroup_name = (char *)arg;
@ -199,7 +248,12 @@ static int opt_duration_cb(const struct option *opt, const char *arg, int unset)
{
struct common_params *params = opt->value;
if (unset || !arg)
if (unset) {
params->duration = 0;
return 0;
}
if (!arg)
return -1;
params->duration = parse_seconds_duration((char *)arg);
@ -233,7 +287,13 @@ static int opt_housekeeping_cb(const struct option *opt, const char *arg, int un
struct common_params *params = opt->value;
int retval;
if (unset || !arg)
if (unset) {
params->hk_cpus = 0;
CPU_ZERO(&params->hk_cpu_set);
return 0;
}
if (!arg)
return -1;
params->hk_cpus = 1;
@ -249,7 +309,13 @@ static int opt_priority_cb(const struct option *opt, const char *arg, int unset)
struct common_params *params = opt->value;
int retval;
if (unset || !arg)
if (unset) {
memset(&params->sched_param, 0, sizeof(params->sched_param));
params->set_sched = 0;
return 0;
}
if (!arg)
return -1;
retval = parse_prio((char *)arg, &params->sched_param);
@ -301,9 +367,8 @@ static int opt_filter_cb(const struct option *opt, const char *arg, int unset)
"osnoise runtime in us", \
opt_osnoise_runtime_cb)
#define OSNOISE_OPT_THRESHOLD OPT_CALLBACK('T', "threshold", &params->threshold, "us", \
"the minimum delta to be considered a noise", \
opt_llong_callback)
#define OSNOISE_OPT_THRESHOLD RTLA_OPT_LLONG('T', "threshold", &params->threshold, "us", \
"the minimum delta to be considered a noise")
/*
* Callback functions for command line options for osnoise tools
@ -315,7 +380,14 @@ static int opt_osnoise_auto_cb(const struct option *opt, const char *arg, int un
struct osnoise_params *params = cb_data->params;
long long auto_thresh;
if (unset || !arg)
if (unset) {
params->common.stop_us = 0;
params->threshold = 0;
cb_data->trace_output = NULL;
return 0;
}
if (!arg)
return -1;
auto_thresh = get_llong_from_str((char *)arg);
@ -332,7 +404,12 @@ static int opt_osnoise_period_cb(const struct option *opt, const char *arg, int
{
unsigned long long *period = opt->value;
if (unset || !arg)
if (unset) {
*period = 0;
return 0;
}
if (!arg)
return -1;
*period = get_llong_from_str((char *)arg);
@ -346,7 +423,12 @@ static int opt_osnoise_runtime_cb(const struct option *opt, const char *arg, int
{
unsigned long long *runtime = opt->value;
if (unset || !arg)
if (unset) {
*runtime = 0;
return 0;
}
if (!arg)
return -1;
*runtime = get_llong_from_str((char *)arg);
@ -360,8 +442,10 @@ static int opt_osnoise_trace_output_cb(const struct option *opt, const char *arg
{
const char **trace_output = opt->value;
if (unset)
return -1;
if (unset) {
*trace_output = NULL;
return 0;
}
if (!arg) {
*trace_output = "osnoise_trace.txt";
@ -412,9 +496,8 @@ static int opt_osnoise_on_end_cb(const struct option *opt, const char *arg, int
"timerlat period in us", \
opt_timerlat_period_cb)
#define TIMERLAT_OPT_STACK OPT_CALLBACK('s', "stack", &params->print_stack, "us", \
"save the stack trace at the IRQ if a thread latency is higher than the argument in us", \
opt_llong_callback)
#define TIMERLAT_OPT_STACK RTLA_OPT_LLONG('s', "stack", &params->print_stack, "us", \
"save the stack trace at the IRQ if a thread latency is higher than the argument in us")
#define TIMERLAT_OPT_NANO OPT_CALLBACK_NOOPT('n', "nano", params, NULL, \
"display data in nanoseconds", \
@ -424,10 +507,10 @@ static int opt_osnoise_on_end_cb(const struct option *opt, const char *arg, int
"set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency", \
opt_dma_latency_cb)
#define TIMERLAT_OPT_DEEPEST_IDLE_STATE OPT_CALLBACK(0, "deepest-idle-state", \
#define TIMERLAT_OPT_DEEPEST_IDLE_STATE RTLA_OPT_INT_DEFVAL(0, "deepest-idle-state", \
&params->deepest_idle_state, "n", \
"only go down to idle state n on cpus used by timerlat to reduce exit from idle latency", \
opt_int_callback)
default_deepest_idle_state)
#define TIMERLAT_OPT_AA_ONLY OPT_CALLBACK(0, "aa-only", params, "us", \
"stop if <us> latency is hit, only printing the auto analysis (reduces CPU usage)", \
@ -459,7 +542,12 @@ static int opt_timerlat_period_cb(const struct option *opt, const char *arg, int
{
long long *period = opt->value;
if (unset || !arg)
if (unset) {
*period = 0;
return 0;
}
if (!arg)
return -1;
*period = get_llong_from_str((char *)arg);
@ -475,7 +563,15 @@ static int opt_timerlat_auto_cb(const struct option *opt, const char *arg, int u
struct timerlat_params *params = cb_data->params;
long long auto_thresh;
if (unset || !arg)
if (unset) {
params->common.stop_total_us = 0;
params->common.stop_us = 0;
params->print_stack = 0;
cb_data->trace_output = NULL;
return 0;
}
if (!arg)
return -1;
auto_thresh = get_llong_from_str((char *)arg);
@ -494,7 +590,12 @@ static int opt_dma_latency_cb(const struct option *opt, const char *arg, int uns
int *dma_latency = opt->value;
int retval;
if (unset || !arg)
if (unset) {
*dma_latency = default_dma_latency;
return 0;
}
if (!arg)
return -1;
retval = strtoi((char *)arg, dma_latency);
@ -511,7 +612,15 @@ static int opt_aa_only_cb(const struct option *opt, const char *arg, int unset)
struct timerlat_params *params = opt->value;
long long auto_thresh;
if (unset || !arg)
if (unset) {
params->common.stop_total_us = 0;
params->common.stop_us = 0;
params->print_stack = 0;
params->common.aa_only = 0;
return 0;
}
if (!arg)
return -1;
auto_thresh = get_llong_from_str((char *)arg);
@ -527,8 +636,10 @@ static int opt_timerlat_trace_output_cb(const struct option *opt, const char *ar
{
const char **trace_output = opt->value;
if (unset)
return -1;
if (unset) {
*trace_output = NULL;
return 0;
}
if (!arg) {
*trace_output = "timerlat_trace.txt";
@ -576,8 +687,11 @@ static int opt_user_threads_cb(const struct option *opt, const char *arg, int un
{
struct timerlat_params *params = opt->value;
if (unset)
return -1;
if (unset) {
params->common.user_workload = false;
params->common.user_data = false;
return 0;
}
params->common.user_workload = true;
params->common.user_data = true;
@ -589,8 +703,10 @@ static int opt_nano_cb(const struct option *opt, const char *arg, int unset)
{
struct timerlat_params *params = opt->value;
if (unset)
return -1;
if (unset) {
params->common.output_divisor = default_output_divisor;
return 0;
}
params->common.output_divisor = 1;
@ -601,7 +717,12 @@ static int opt_stack_format_cb(const struct option *opt, const char *arg, int un
{
int *format = opt->value;
if (unset || !arg)
if (unset) {
*format = default_stack_format;
return 0;
}
if (!arg)
return -1;
*format = parse_stack_format((char *)arg);
@ -616,7 +737,13 @@ static int opt_timerlat_align_cb(const struct option *opt, const char *arg, int
{
struct timerlat_params *params = opt->value;
if (unset || !arg)
if (unset) {
params->timerlat_align = false;
params->timerlat_align_us = 0;
return 0;
}
if (!arg)
return -1;
params->timerlat_align = true;
@ -662,7 +789,12 @@ static int opt_bucket_size_cb(const struct option *opt, const char *arg, int uns
{
int *bucket_size = opt->value;
if (unset || !arg)
if (unset) {
*bucket_size = default_bucket_size;
return 0;
}
if (!arg)
return -1;
*bucket_size = get_llong_from_str((char *)arg);
@ -676,7 +808,12 @@ static int opt_entries_cb(const struct option *opt, const char *arg, int unset)
{
int *entries = opt->value;
if (unset || !arg)
if (unset) {
*entries = default_entries;
return 0;
}
if (!arg)
return -1;
*entries = get_llong_from_str((char *)arg);