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rtla/timerlat_hist: Add timerlat user-space support

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Add the support for running timerlat threads in user-space. In this
mode, enabled with -u/--user-threads, timerlat dispatches user-space
processes that will loop in the timerlat_fd, measuring the overhead
for going to user-space and then returning to the kernel - in addition
to the existing measurements.

Here is one example of the tool's output with -u enabled:

  $ sudo timerlat  hist -u -c 1-3 -d 600
  # RTLA timerlat histogram
  # Time unit is microseconds (us)
  # Duration:   0 00:10:01
  Index   IRQ-001   Thr-001   Usr-001   IRQ-002   Thr-002   Usr-002   IRQ-003   Thr-003   Usr-003
  0        477555         0         0    425287         0         0    474357         0         0
  1        122385      7998         0    174616      1921         0    125412      3138         0
  2            47    587376    492150        89    594717    447830       147    593463    454872
  3            11      2549    101930         7      2682    145580        64      2530    138680
  4             3      1954      2833         1       463      4917        11       548      4656
  5             0        60      1037         0       138      1117         6       179      1130
  6             0        26      1837         0        38       277         1        76       339
  7             0        15       143         0        28       147         2        37       156
  8             0        10        23         0        11        75         0        12        80
  9             0         7        17         0         0        26         0        11        42
  10            0         2        11         0         0        18         0         2        20
  11            0         0         7         0         1         8         0         2        12
  12            0         0         6         0         1         4         0         2         8
  13            0         1         3         0         0         0         0         0         1
  14            0         1         0         0         0         1         0         0         2
  15            0         1         0         0         0         0         0         0         2
  16            0         1         2         0         0         0         0         0         0
  17            0         0         1         0         0         0         0         0         0
  19            0         0         1         0         0         0         0         0         0
  over:         0         0         0         0         0         0         0         0         0
  count:   600001    600001    600001    600000    600000    600000    600000    600000    600000
  min:          0         1         2         0         1         2         0         1         2
  avg:          0         1         2         0         2         2         0         2         2
  max:          4        16        19         4        12        14         7        12        15

The tuning setup like -p or -C work for the user-space threads as well.

Link: https://lkml.kernel.org/r/b6a042d55003c4a67ff7dce28d96044b7044f00d.1686066600.git.bristot@kernel.org

Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Daniel Bristot de Oliveira 2023-06-06 18:12:24 +02:00 committed by Steven Rostedt (Google)
parent cdca4f4e5e
commit ed774f7481
1 changed files with 118 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

129
tools/tracing/rtla/src/timerlat_hist.c
View File

@ -12,11 +12,13 @@
#include <stdio.h>
#include <time.h>
#include <sched.h>
#include <pthread.h>
#include "utils.h"
#include "osnoise.h"
#include "timerlat.h"
#include "timerlat_aa.h"
#include "timerlat_u.h"
struct timerlat_hist_params {
char *cpus;
@ -37,6 +39,7 @@ struct timerlat_hist_params {
int hk_cpus;
int no_aa;
int dump_tasks;
int user_hist;
cpu_set_t hk_cpu_set;
struct sched_attr sched_param;
struct trace_events *events;
@ -53,9 +56,11 @@ struct timerlat_hist_params {
struct timerlat_hist_cpu {
int *irq;
int *thread;
int *user;
int irq_count;
int thread_count;
int user_count;
unsigned long long min_irq;
unsigned long long sum_irq;
@ -64,6 +69,10 @@ struct timerlat_hist_cpu {
unsigned long long min_thread;
unsigned long long sum_thread;
unsigned long long max_thread;
unsigned long long min_user;
unsigned long long sum_user;
unsigned long long max_user;
};
struct timerlat_hist_data {
@ -88,6 +97,10 @@ timerlat_free_histogram(struct timerlat_hist_data *data)
if (data->hist[cpu].thread)
free(data->hist[cpu].thread);
if (data->hist[cpu].user)
free(data->hist[cpu].user);
}
/* one set of histograms per CPU */
@ -124,15 +137,21 @@ static struct timerlat_hist_data
data->hist[cpu].irq = calloc(1, sizeof(*data->hist->irq) * (entries + 1));
if (!data->hist[cpu].irq)
goto cleanup;
data->hist[cpu].thread = calloc(1, sizeof(*data->hist->thread) * (entries + 1));
if (!data->hist[cpu].thread)
goto cleanup;
data->hist[cpu].user = calloc(1, sizeof(*data->hist->user) * (entries + 1));
if (!data->hist[cpu].user)
goto cleanup;
}
/* set the min to max */
for (cpu = 0; cpu < nr_cpus; cpu++) {
data->hist[cpu].min_irq = ~0;
data->hist[cpu].min_thread = ~0;
data->hist[cpu].min_user = ~0;
}
return data;
@ -147,7 +166,7 @@ static struct timerlat_hist_data
*/
static void
timerlat_hist_update(struct osnoise_tool *tool, int cpu,
unsigned long long thread,
unsigned long long context,
unsigned long long latency)
{
struct timerlat_hist_params *params = tool->params;
@ -162,18 +181,24 @@ timerlat_hist_update(struct osnoise_tool *tool, int cpu,
if (data->bucket_size)
bucket = latency / data->bucket_size;
if (!thread) {
if (!context) {
hist = data->hist[cpu].irq;
data->hist[cpu].irq_count++;
update_min(&data->hist[cpu].min_irq, &latency);
update_sum(&data->hist[cpu].sum_irq, &latency);
update_max(&data->hist[cpu].max_irq, &latency);
} else {
} else if (context == 1) {
hist = data->hist[cpu].thread;
data->hist[cpu].thread_count++;
update_min(&data->hist[cpu].min_thread, &latency);
update_sum(&data->hist[cpu].sum_thread, &latency);
update_max(&data->hist[cpu].max_thread, &latency);
} else { /* user */
hist = data->hist[cpu].user;
data->hist[cpu].user_count++;
update_min(&data->hist[cpu].min_user, &latency);
update_sum(&data->hist[cpu].sum_user, &latency);
update_max(&data->hist[cpu].max_user, &latency);
}
if (bucket < entries)
@ -190,16 +215,16 @@ timerlat_hist_handler(struct trace_seq *s, struct tep_record *record,
struct tep_event *event, void *data)
{
struct trace_instance *trace = data;
unsigned long long thread, latency;
unsigned long long context, latency;
struct osnoise_tool *tool;
int cpu = record->cpu;
tool = container_of(trace, struct osnoise_tool, trace);
tep_get_field_val(s, event, "context", record, &thread, 1);
tep_get_field_val(s, event, "context", record, &context, 1);
tep_get_field_val(s, event, "timer_latency", record, &latency, 1);
timerlat_hist_update(tool, cpu, thread, latency);
timerlat_hist_update(tool, cpu, context, latency);
return 0;
}
@ -241,6 +266,9 @@ static void timerlat_hist_header(struct osnoise_tool *tool)
if (!params->no_thread)
trace_seq_printf(s, " Thr-%03d", cpu);
if (params->user_hist)
trace_seq_printf(s, " Usr-%03d", cpu);
}
trace_seq_printf(s, "\n");
@ -279,6 +307,10 @@ timerlat_print_summary(struct timerlat_hist_params *params,
if (!params->no_thread)
trace_seq_printf(trace->seq, "%9d ",
data->hist[cpu].thread_count);
if (params->user_hist)
trace_seq_printf(trace->seq, "%9d ",
data->hist[cpu].user_count);
}
trace_seq_printf(trace->seq, "\n");
@ -299,6 +331,10 @@ timerlat_print_summary(struct timerlat_hist_params *params,
if (!params->no_thread)
trace_seq_printf(trace->seq, "%9llu ",
data->hist[cpu].min_thread);
if (params->user_hist)
trace_seq_printf(trace->seq, "%9llu ",
data->hist[cpu].min_user);
}
trace_seq_printf(trace->seq, "\n");
@ -323,7 +359,15 @@ timerlat_print_summary(struct timerlat_hist_params *params,
if (!params->no_thread) {
if (data->hist[cpu].thread_count)
trace_seq_printf(trace->seq, "%9llu ",
data->hist[cpu].sum_thread / data->hist[cpu].thread_count);
data->hist[cpu].sum_thread / data->hist[cpu].thread_count);
else
trace_seq_printf(trace->seq, " - ");
}
if (params->user_hist) {
if (data->hist[cpu].user_count)
trace_seq_printf(trace->seq, "%9llu ",
data->hist[cpu].sum_user / data->hist[cpu].user_count);
else
trace_seq_printf(trace->seq, " - ");
}
@ -347,6 +391,10 @@ timerlat_print_summary(struct timerlat_hist_params *params,
if (!params->no_thread)
trace_seq_printf(trace->seq, "%9llu ",
data->hist[cpu].max_thread);
if (params->user_hist)
trace_seq_printf(trace->seq, "%9llu ",
data->hist[cpu].max_user);
}
trace_seq_printf(trace->seq, "\n");
trace_seq_do_printf(trace->seq);
@ -392,6 +440,12 @@ timerlat_print_stats(struct timerlat_hist_params *params, struct osnoise_tool *t
data->hist[cpu].thread[bucket]);
}
if (params->user_hist) {
total += data->hist[cpu].user[bucket];
trace_seq_printf(trace->seq, "%9d ",
data->hist[cpu].user[bucket]);
}
}
if (total == 0 && !params->with_zeros) {
@ -421,6 +475,10 @@ timerlat_print_stats(struct timerlat_hist_params *params, struct osnoise_tool *t
if (!params->no_thread)
trace_seq_printf(trace->seq, "%9d ",
data->hist[cpu].thread[data->entries]);
if (params->user_hist)
trace_seq_printf(trace->seq, "%9d ",
data->hist[cpu].user[data->entries]);
}
trace_seq_printf(trace->seq, "\n");
trace_seq_do_printf(trace->seq);
@ -441,7 +499,7 @@ static void timerlat_hist_usage(char *usage)
" usage: [rtla] timerlat hist [-h] [-q] [-d s] [-D] [-n] [-a us] [-p us] [-i us] [-T us] [-s us] \\",
" [-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
" [-P priority] [-E N] [-b N] [--no-irq] [--no-thread] [--no-header] [--no-summary] \\",
" [--no-index] [--with-zeros] [--dma-latency us] [-C[=cgroup_name]] [--no-aa] [--dump-task]",
" [--no-index] [--with-zeros] [--dma-latency us] [-C[=cgroup_name]] [--no-aa] [--dump-task] [-u]",
"",
" -h/--help: print this menu",
" -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
@ -476,6 +534,7 @@ static void timerlat_hist_usage(char *usage)
" f:prio - use SCHED_FIFO with prio",
" d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
" in nanoseconds",
" -u/--user-threads: use rtla user-space threads instead of in-kernel timerlat threads",
NULL,
};
@ -532,6 +591,7 @@ static struct timerlat_hist_params
{"stack", required_argument, 0, 's'},
{"thread", required_argument, 0, 'T'},
{"trace", optional_argument, 0, 't'},
{"user-threads", no_argument, 0, 'u'},
{"event", required_argument, 0, 'e'},
{"no-irq", no_argument, 0, '0'},
{"no-thread", no_argument, 0, '1'},
@ -550,7 +610,7 @@ static struct timerlat_hist_params
/* getopt_long stores the option index here. */
int option_index = 0;
c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:i:np:P:s:t::T:0123456:7:8:9\1",
c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:i:np:P:s:t::T:u0123456:7:8:9\1",
long_options, &option_index);
/* detect the end of the options. */
@ -660,6 +720,9 @@ static struct timerlat_hist_params
else
params->trace_output = "timerlat_trace.txt";
break;
case 'u':
params->user_hist = 1;
break;
case '0': /* no irq */
params->no_irq = 1;
break;
@ -744,7 +807,7 @@ static struct timerlat_hist_params
static int
timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_params *params)
{
int retval;
int retval, i;
if (!params->sleep_time)
params->sleep_time = 1;
@ -755,6 +818,9 @@ timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_param
err_msg("Failed to apply CPUs config\n");
goto out_err;
}
} else {
for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
CPU_SET(i, &params->monitored_cpus);
}
if (params->stop_us) {
@ -807,6 +873,14 @@ timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_param
auto_house_keeping(&params->monitored_cpus);
}
if (params->user_hist) {
retval = osnoise_set_workload(tool->context, 0);
if (retval) {
err_msg("Failed to set OSNOISE_WORKLOAD option\n");
goto out_err;
}
}
return 0;
out_err:
@ -867,11 +941,13 @@ int timerlat_hist_main(int argc, char *argv[])
{
struct timerlat_hist_params *params;
struct osnoise_tool *record = NULL;
struct timerlat_u_params params_u;
struct osnoise_tool *tool = NULL;
struct osnoise_tool *aa = NULL;
struct trace_instance *trace;
int dma_latency_fd = -1;
int return_value = 1;
pthread_t timerlat_u;
int retval;
params = timerlat_hist_parse_args(argc, argv);
@ -906,7 +982,7 @@ int timerlat_hist_main(int argc, char *argv[])
}
}
if (params->cgroup) {
if (params->cgroup && !params->user_hist) {
retval = set_comm_cgroup("timerlat/", params->cgroup_name);
if (!retval) {
err_msg("Failed to move threads to cgroup\n");
@ -970,6 +1046,25 @@ int timerlat_hist_main(int argc, char *argv[])
tool->start_time = time(NULL);
timerlat_hist_set_signals(params);
if (params->user_hist) {
/* rtla asked to stop */
params_u.should_run = 1;
/* all threads left */
params_u.stopped_running = 0;
params_u.set = &params->monitored_cpus;
if (params->set_sched)
params_u.sched_param = &params->sched_param;
else
params_u.sched_param = NULL;
params_u.cgroup_name = params->cgroup_name;
retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, &params_u);
if (retval)
err_msg("Error creating timerlat user-space threads\n");
}
while (!stop_tracing) {
sleep(params->sleep_time);
@ -986,6 +1081,18 @@ int timerlat_hist_main(int argc, char *argv[])
if (trace_is_off(&tool->trace, &record->trace))
break;
/* is there still any user-threads ? */
if (params->user_hist) {
if (params_u.stopped_running) {
debug_msg("timerlat user-space threads stopped!\n");
break;
}
}
}
if (params->user_hist && !params_u.stopped_running) {
params_u.should_run = 0;
sleep(1);
}
timerlat_print_stats(params, tool);