[for-next][PATCH 02/11] rtla: Add --house-keeping option

Steven Rostedt
2023-06-13T22:08:37Z

To avoid having rtla interfering with the measurement threads, add an
option for the user to set the CPUs in which rtla should run. For
instance:

# rtla timerlat top -H 0 -c 1-7

Will place rtla in the CPU 0, while running the measurement threads in
the CPU 1-7.

Link: https://lkml.kernel.org/r/6a6c78a579a96ba8b02ae67ee1e0ba2cb5e03c4a.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>
Suggested-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>
---
Documentation/tools/rtla/common_options.rst | 4 ++
tools/tracing/rtla/src/osnoise_hist.c | 29 +++++++++--
tools/tracing/rtla/src/osnoise_top.c | 27 +++++++++-
tools/tracing/rtla/src/timerlat_hist.c | 27 +++++++++-
tools/tracing/rtla/src/timerlat_top.c | 27 +++++++++-
tools/tracing/rtla/src/utils.c | 58 +++++++++++++++++++++
tools/tracing/rtla/src/utils.h | 3 ++
7 files changed, 166 insertions(+), 9 deletions(-)

diff --git a/Documentation/tools/rtla/common_options.rst b/Documentation/tools/rtla/common_options.rst
index ede07359d93c..aeb91ff3bd68 100644
--- a/Documentation/tools/rtla/common_options.rst
+++ b/Documentation/tools/rtla/common_options.rst
@@ -2,6 +2,10 @@

Set the osnoise tracer to run the sample threads in the cpu-list.

+**-H**, **--house-keeping** *cpu-list*
+
+ Run rtla control threads only on the given cpu-list.
+
**-d**, **--duration** *time[s|m|h|d]*

Set the duration of the session.
diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 076f4c6af3dd..d2b68177ffac 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -3,6 +3,7 @@
* Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
*/

+#define _GNU_SOURCE
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
@@ -11,6 +12,7 @@
#include <errno.h>
#include <stdio.h>
#include <time.h>
+#include <sched.h>

#include "utils.h"
#include "osnoise.h"
@@ -30,6 +32,8 @@ struct osnoise_hist_params {
int set_sched;
int output_divisor;
int cgroup;
+ int hk_cpus;
+ cpu_set_t hk_cpu_set;
struct sched_attr sched_param;
struct trace_events *events;

@@ -434,8 +438,8 @@ static void osnoise_hist_usage(char *usage)
"",
" usage: rtla osnoise hist [-h] [-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
" [-T us] [-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] \\",
- " [-c cpu-list] [-P priority] [-b N] [-E N] [--no-header] [--no-summary] [--no-index] \\",
- " [--with-zeros] [-C[=cgroup_name]]",
+ " [-c cpu-list] [-H cpu-list] [-P priority] [-b N] [-E N] [--no-header] [--no-summary] \\",
+ " [--no-index] [--with-zeros] [-C[=cgroup_name]]",
"",
" -h/--help: print this menu",
" -a/--auto: set automatic trace mode, stopping the session if argument in us sample is hit",
@@ -445,6 +449,7 @@ static void osnoise_hist_usage(char *usage)
" -S/--stop-total us: stop trace if the total sample is higher than the argument in us",
" -T/--threshold us: the minimum delta to be considered a noise",
" -c/--cpus cpu-list: list of cpus to run osnoise threads",
+ " -H/--house-keeping cpus: run rtla control threads only on the given cpus",
" -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
" -d/--duration time[s|m|h|d]: duration of the session",
" -D/--debug: print debug info",
@@ -507,6 +512,7 @@ static struct osnoise_hist_params
{"cgroup", optional_argument, 0, 'C'},
{"debug", no_argument, 0, 'D'},
{"duration", required_argument, 0, 'd'},
+ {"house-keeping", required_argument, 0, 'H'},
{"help", no_argument, 0, 'h'},
{"period", required_argument, 0, 'p'},
{"priority", required_argument, 0, 'P'},
@@ -528,7 +534,7 @@ static struct osnoise_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:Dhp:P:r:s:S:t::T:01234:5:",
+ c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:p:P:r:s:S:t::T:01234:5:",
long_options, &option_index);

/* detect the end of the options. */
@@ -597,6 +603,14 @@ static struct osnoise_hist_params
case '?':
osnoise_hist_usage(NULL);
break;
+ case 'H':
+ params->hk_cpus = 1;
+ retval = parse_cpu_set(optarg, &params->hk_cpu_set);
+ if (retval) {
+ err_msg("Error parsing house keeping CPUs\n");
+ exit(EXIT_FAILURE);
+ }
+ break;
case 'p':
params->period = get_llong_from_str(optarg);
if (params->period > 10000000)
@@ -732,6 +746,15 @@ osnoise_hist_apply_config(struct osnoise_tool *tool, struct osnoise_hist_params
}
}

+ if (params->hk_cpus) {
+ retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
+ &params->hk_cpu_set);
+ if (retval == -1) {
+ err_msg("Failed to set rtla to the house keeping CPUs\n");
+ goto out_err;
+ }
+ }
+
return 0;

out_err:
diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 139d8d392540..fcf6c14ce1bc 100644
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -3,6 +3,7 @@
* Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
*/

+#define _GNU_SOURCE
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
@@ -10,6 +11,7 @@
#include <unistd.h>
#include <stdio.h>
#include <time.h>
+#include <sched.h>

#include "osnoise.h"
#include "utils.h"
@@ -37,6 +39,8 @@ struct osnoise_top_params {
int quiet;
int set_sched;
int cgroup;
+ int hk_cpus;
+ cpu_set_t hk_cpu_set;
struct sched_attr sched_param;
struct trace_events *events;
enum osnoise_mode mode;
@@ -278,7 +282,7 @@ static void osnoise_top_usage(struct osnoise_top_params *params, char *usage)
static const char * const msg[] = {
" [-h] [-q] [-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
" [-T us] [-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] \\",
- " [-c cpu-list] [-P priority] [-C[=cgroup_name]]",
+ " [-c cpu-list] [-H cpu-list] [-P priority] [-C[=cgroup_name]]",
"",
" -h/--help: print this menu",
" -a/--auto: set automatic trace mode, stopping the session if argument in us sample is hit",
@@ -288,6 +292,7 @@ static void osnoise_top_usage(struct osnoise_top_params *params, char *usage)
" -S/--stop-total us: stop trace if the total sample is higher than the argument in us",
" -T/--threshold us: the minimum delta to be considered a noise",
" -c/--cpus cpu-list: list of cpus to run osnoise threads",
+ " -H/--house-keeping cpus: run rtla control threads only on the given cpus",
" -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
" -d/--duration time[s|m|h|d]: duration of the session",
" -D/--debug: print debug info",
@@ -354,6 +359,7 @@ struct osnoise_top_params *osnoise_top_parse_args(int argc, char **argv)
{"debug", no_argument, 0, 'D'},
{"duration", required_argument, 0, 'd'},
{"event", required_argument, 0, 'e'},
+ {"house-keeping", required_argument, 0, 'H'},
{"help", no_argument, 0, 'h'},
{"period", required_argument, 0, 'p'},
{"priority", required_argument, 0, 'P'},
@@ -371,7 +377,7 @@ struct osnoise_top_params *osnoise_top_parse_args(int argc, char **argv)
/* getopt_long stores the option index here. */
int option_index = 0;

- c = getopt_long(argc, argv, "a:c:C::d:De:hp:P:qr:s:S:t::T:0:1:",
+ c = getopt_long(argc, argv, "a:c:C::d:De:hH:p:P:qr:s:S:t::T:0:1:",
long_options, &option_index);

/* Detect the end of the options. */
@@ -430,6 +436,14 @@ struct osnoise_top_params *osnoise_top_parse_args(int argc, char **argv)
case '?':
osnoise_top_usage(params, NULL);
break;
+ case 'H':
+ params->hk_cpus = 1;
+ retval = parse_cpu_set(optarg, &params->hk_cpu_set);
+ if (retval) {
+ err_msg("Error parsing house keeping CPUs\n");
+ exit(EXIT_FAILURE);
+ }
+ break;
case 'p':
params->period = get_llong_from_str(optarg);
if (params->period > 10000000)
@@ -561,6 +575,15 @@ osnoise_top_apply_config(struct osnoise_tool *tool, struct osnoise_top_params *p
}
}

+ if (params->hk_cpus) {
+ retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
+ &params->hk_cpu_set);
+ if (retval == -1) {
+ err_msg("Failed to set rtla to the house keeping CPUs\n");
+ goto out_err;
+ }
+ }
+
return 0;

out_err:
diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 459c159923e8..d48c05d238f9 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -3,6 +3,7 @@
* Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
*/

+#define _GNU_SOURCE
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
@@ -10,6 +11,7 @@
#include <unistd.h>
#include <stdio.h>
#include <time.h>
+#include <sched.h>

#include "utils.h"
#include "osnoise.h"
@@ -31,6 +33,8 @@ struct timerlat_hist_params {
int set_sched;
int dma_latency;
int cgroup;
+ int hk_cpus;
+ cpu_set_t hk_cpu_set;
struct sched_attr sched_param;
struct trace_events *events;
char no_irq;
@@ -432,7 +436,7 @@ static void timerlat_hist_usage(char *usage)
char *msg[] = {
"",
" 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] \\",
+ " [-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]]",
"",
@@ -443,6 +447,7 @@ static void timerlat_hist_usage(char *usage)
" -T/--thread us: stop trace if the thread latency is higher than the argument in us",
" -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
" -c/--cpus cpus: run the tracer only on the given cpus",
+ " -H/--house-keeping cpus: run rtla control threads only on the given cpus",
" -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
" -d/--duration time[m|h|d]: duration of the session in seconds",
" -D/--debug: print debug info",
@@ -513,6 +518,7 @@ static struct timerlat_hist_params
{"debug", no_argument, 0, 'D'},
{"entries", required_argument, 0, 'E'},
{"duration", required_argument, 0, 'd'},
+ {"house-keeping", required_argument, 0, 'H'},
{"help", no_argument, 0, 'h'},
{"irq", required_argument, 0, 'i'},
{"nano", no_argument, 0, 'n'},
@@ -537,7 +543,7 @@ 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:Dhi:np:P:s:t::T:0123456:7:8:",
+ c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:i:np:P:s:t::T:0123456:7:8:",
long_options, &option_index);

/* detect the end of the options. */
@@ -608,6 +614,14 @@ static struct timerlat_hist_params
case '?':
timerlat_hist_usage(NULL);
break;
+ case 'H':
+ params->hk_cpus = 1;
+ retval = parse_cpu_set(optarg, &params->hk_cpu_set);
+ if (retval) {
+ err_msg("Error parsing house keeping CPUs\n");
+ exit(EXIT_FAILURE);
+ }
+ break;
case 'i':
params->stop_us = get_llong_from_str(optarg);
break;
@@ -755,6 +769,15 @@ timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_param
}
}

+ if (params->hk_cpus) {
+ retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
+ &params->hk_cpu_set);
+ if (retval == -1) {
+ err_msg("Failed to set rtla to the house keeping CPUs\n");
+ goto out_err;
+ }
+ }
+
return 0;

out_err:
diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index a19cbc2aa1f4..5395d1c5921e 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -3,6 +3,7 @@
* Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
*/

+#define _GNU_SOURCE
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
@@ -11,6 +12,7 @@
#include <stdio.h>
#include <time.h>
#include <errno.h>
+#include <sched.h>

#include "utils.h"
#include "osnoise.h"
@@ -37,6 +39,8 @@ struct timerlat_top_params {
int aa_only;
int dump_tasks;
int cgroup;
+ int hk_cpus;
+ cpu_set_t hk_cpu_set;
struct sched_attr sched_param;
struct trace_events *events;
};
@@ -286,7 +290,7 @@ static void timerlat_top_usage(char *usage)
static const char *const msg[] = {
"",
" usage: rtla timerlat [top] [-h] [-q] [-a us] [-d s] [-D] [-n] [-p us] [-i us] [-T us] [-s us] \\",
- " [[-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] \\",
+ " [[-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
" [-P priority] [--dma-latency us] [--aa-only us] [-C[=cgroup_name]]",
"",
" -h/--help: print this menu",
@@ -297,6 +301,7 @@ static void timerlat_top_usage(char *usage)
" -T/--thread us: stop trace if the thread latency is higher than the argument in us",
" -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
" -c/--cpus cpus: run the tracer only on the given cpus",
+ " -H/--house-keeping cpus: run rtla control threads only on the given cpus",
" -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
" -d/--duration time[m|h|d]: duration of the session in seconds",
" -D/--debug: print debug info",
@@ -360,6 +365,7 @@ static struct timerlat_top_params
{"duration", required_argument, 0, 'd'},
{"event", required_argument, 0, 'e'},
{"help", no_argument, 0, 'h'},
+ {"house-keeping", required_argument, 0, 'H'},
{"irq", required_argument, 0, 'i'},
{"nano", no_argument, 0, 'n'},
{"period", required_argument, 0, 'p'},
@@ -380,7 +386,7 @@ static struct timerlat_top_params
/* getopt_long stores the option index here. */
int option_index = 0;

- c = getopt_long(argc, argv, "a:c:C::d:De:hi:np:P:qs:t::T:0:1:2:345:",
+ c = getopt_long(argc, argv, "a:c:C::d:De:hH:i:np:P:qs:t::T:0:1:2:345:",
long_options, &option_index);

/* detect the end of the options. */
@@ -454,6 +460,14 @@ static struct timerlat_top_params
case '?':
timerlat_top_usage(NULL);
break;
+ case 'H':
+ params->hk_cpus = 1;
+ retval = parse_cpu_set(optarg, &params->hk_cpu_set);
+ if (retval) {
+ err_msg("Error parsing house keeping CPUs\n");
+ exit(EXIT_FAILURE);
+ }
+ break;
case 'i':
params->stop_us = get_llong_from_str(optarg);
break;
@@ -598,6 +612,15 @@ timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_top_params *
}
}

+ if (params->hk_cpus) {
+ retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
+ &params->hk_cpu_set);
+ if (retval == -1) {
+ err_msg("Failed to set rtla to the house keeping CPUs\n");
+ goto out_err;
+ }
+ }
+
return 0;

out_err:
diff --git a/tools/tracing/rtla/src/utils.c b/tools/tracing/rtla/src/utils.c
index bcc0a9f39cfe..ee6fab09acae 100644
--- a/tools/tracing/rtla/src/utils.c
+++ b/tools/tracing/rtla/src/utils.c
@@ -3,6 +3,7 @@
* Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
*/

+#define _GNU_SOURCE
#include <dirent.h>
#include <stdarg.h>
#include <stdlib.h>
@@ -150,6 +151,63 @@ int parse_cpu_list(char *cpu_list, char **monitored_cpus)
return 1;
}

+/*
+ * parse_cpu_set - parse a cpu_list filling cpu_set_t argument
+ *
+ * Receives a cpu list, like 1-3,5 (cpus 1, 2, 3, 5), and then set
+ * filling cpu_set_t argument.
+ *
+ * Returns 1 on success, 0 otherwise.
+ */
+int parse_cpu_set(char *cpu_list, cpu_set_t *set)
+{
+ const char *p;
+ int end_cpu;
+ int nr_cpus;
+ int cpu;
+ int i;
+
+ CPU_ZERO(set);
+
+ nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+
+ for (p = cpu_list; *p; ) {
+ cpu = atoi(p);
+ if (cpu < 0 || (!cpu && *p != '0') || cpu >= nr_cpus)
+ goto err;
+
+ while (isdigit(*p))
+ p++;
+ if (*p == '-') {
+ p++;
+ end_cpu = atoi(p);
+ if (end_cpu < cpu || (!end_cpu && *p != '0') || end_cpu >= nr_cpus)
+ goto err;
+ while (isdigit(*p))
+ p++;
+ } else
+ end_cpu = cpu;
+
+ if (cpu == end_cpu) {
+ debug_msg("cpu_set: adding cpu %d\n", cpu);
+ CPU_SET(cpu, set);
+ } else {
+ for (i = cpu; i <= end_cpu; i++) {
+ debug_msg("cpu_set: adding cpu %d\n", i);
+ CPU_SET(i, set);
+ }
+ }
+
+ if (*p == ',')
+ p++;
+ }
+
+ return 0;
+err:
+ debug_msg("Error parsing the cpu set %s\n", cpu_list);
+ return 1;
+}
+
/*
* parse_duration - parse duration with s/m/h/d suffix converting it to seconds
*/
diff --git a/tools/tracing/rtla/src/utils.h b/tools/tracing/rtla/src/utils.h
index 42b6f099d10a..9ab2f0d7bc1c 100644
--- a/tools/tracing/rtla/src/utils.h
+++ b/tools/tracing/rtla/src/utils.h
@@ -1,6 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
+
#include <stdint.h>
#include <time.h>
+#include <sched.h>

/*
* '18446744073709551615\0'
@@ -54,6 +56,7 @@ struct sched_attr {
};

int parse_prio(char *arg, struct sched_attr *sched_param);
+int parse_cpu_set(char *cpu_list, cpu_set_t *set);
int set_comm_sched_attr(const char *comm_prefix, struct sched_attr *attr);
int set_comm_cgroup(const char *comm_prefix, const char *cgroup);
int set_cpu_dma_latency(int32_t latency);
--
2.39.2