rtla: Add --house-keeping option

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>

diff --git a/Documentation/tools/rtla/common_options.rst b/Documentation/tools/rtla/common_options.rst
index ede0735..aeb91ff 100644 (file)
--- 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 076f4c6..d2b6817 100644 (file)
--- 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 139d8d3..fcf6c14 100644 (file)
--- 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 459c159..d48c05d 100644 (file)
--- 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 a19cbc2..5395d1c 100644 (file)
--- 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 bcc0a9f..ee6fab0 100644 (file)
--- 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>
@@ -151,6 +152,63 @@ err:
 }
 
 /*
+ * 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
  */
 long parse_seconds_duration(char *val)

diff --git a/tools/tracing/rtla/src/utils.h b/tools/tracing/rtla/src/utils.h
index 42b6f09..9ab2f0d 100644 (file)
--- 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);