tools/rtla: Consolidate nr_cpus usage across all tools

sysconf(_SC_NPROCESSORS_CONF) (via get_nprocs_conf) reflects
cpu_possible_mask, which is fixed at boot time, so querying it
repeatedly is unnecessary.

Replace multiple calls to sysconf(_SC_NPROCESSORS_CONF) with a single
global nr_cpus variable initialized once at startup.

`#pragma once` in timerlat_u.h is needed for pre-C23 compilers to avoid
redefinition errors.

Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Link: https://lore.kernel.org/r/20260306194953.2511960-2-costa.shul@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>

diff --git a/tools/tracing/rtla/src/common.c b/tools/tracing/rtla/src/common.c
index f310b0d59ad3e3ae9a168a5a8180a072ec1c74ff..a31fbaea5da6b972d78aa09e6066a82fd6aab3b1 100644 (file)
--- a/tools/tracing/rtla/src/common.c
+++ b/tools/tracing/rtla/src/common.c
@@ -5,12 +5,14 @@
 #include <signal.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
 #include <getopt.h>
+#include <sys/sysinfo.h>
+
 #include "common.h"
 
 struct trace_instance *trace_inst;
 volatile int stop_tracing;
+int nr_cpus;
 
 static void stop_trace(int sig)
 {
@@ -165,7 +167,7 @@ common_apply_config(struct osnoise_tool *tool, struct common_params *params)
        }
 
        if (!params->cpus) {
-               for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
+               for (i = 0; i < nr_cpus; i++)
                        CPU_SET(i, &params->monitored_cpus);
        }
 
@@ -213,6 +215,7 @@ int run_tool(struct tool_ops *ops, int argc, char *argv[])
        bool stopped;
        int retval;
 
+       nr_cpus = get_nprocs_conf();
        params = ops->parse_args(argc, argv);
        if (!params)
                exit(1);

diff --git a/tools/tracing/rtla/src/common.h b/tools/tracing/rtla/src/common.h
index d4b3715700be73952bc0d1210a2adafbf0457add..90a3c0d1dbf399dfc7c2b9ce3f6e6a1bed3c040d 100644 (file)
--- a/tools/tracing/rtla/src/common.h
+++ b/tools/tracing/rtla/src/common.h
@@ -108,6 +108,8 @@ struct common_params {
        struct timerlat_u_params user;
 };
 
+extern int nr_cpus;
+
 #define for_each_monitored_cpu(cpu, nr_cpus, common) \
        for (cpu = 0; cpu < nr_cpus; cpu++) \
                if (!(common)->cpus || CPU_ISSET(cpu, &(common)->monitored_cpus))

diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 5c863e7aad28b4cfedaedf49e2938cbae49d398b..00b8c95cbf85cf79338b55489d5c9a15ca99d45b 100644 (file)
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -646,9 +646,6 @@ static struct osnoise_tool
 *osnoise_init_hist(struct common_params *params)
 {
        struct osnoise_tool *tool;
-       int nr_cpus;
-
-       nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
 
        tool = osnoise_init_tool("osnoise_hist");
        if (!tool)

diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index b7aed40fd2164f1e5390ddc3b1db6fd16ad28085..9a6cd9a2470ab0af6f4b14cff684d3775c1ced04 100644 (file)
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -232,12 +232,8 @@ osnoise_print_stats(struct osnoise_tool *top)
 {
        struct osnoise_params *params = to_osnoise_params(top->params);
        struct trace_instance *trace = &top->trace;
-       static int nr_cpus = -1;
        int i;
 
-       if (nr_cpus == -1)
-               nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
-
        if (!params->common.quiet)
                clear_terminal(trace->seq);
 
@@ -494,9 +490,6 @@ out_err:
 struct osnoise_tool *osnoise_init_top(struct common_params *params)
 {
        struct osnoise_tool *tool;
-       int nr_cpus;
-
-       nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
 
        tool = osnoise_init_tool("osnoise_top");
        if (!tool)

diff --git a/tools/tracing/rtla/src/timerlat.c b/tools/tracing/rtla/src/timerlat.c
index 9e4daed0aafc659527f42bc5ec1893d5119601d1..31c921efa7c16e45a3cd468d374a61ce130ea4f7 100644 (file)
--- a/tools/tracing/rtla/src/timerlat.c
+++ b/tools/tracing/rtla/src/timerlat.c
@@ -99,7 +99,7 @@ out_err:
 int timerlat_enable(struct osnoise_tool *tool)
 {
        struct timerlat_params *params = to_timerlat_params(tool->params);
-       int retval, nr_cpus, i;
+       int retval, i;
 
        if (params->dma_latency >= 0) {
                dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
@@ -115,8 +115,6 @@ int timerlat_enable(struct osnoise_tool *tool)
                        return -1;
                }
 
-               nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
-
                for_each_monitored_cpu(i, nr_cpus, &params->common) {
                        if (save_cpu_idle_disable_state(i) < 0) {
                                err_msg("Could not save cpu idle state.\n");
@@ -214,7 +212,6 @@ void timerlat_analyze(struct osnoise_tool *tool, bool stopped)
 void timerlat_free(struct osnoise_tool *tool)
 {
        struct timerlat_params *params = to_timerlat_params(tool->params);
-       int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
        int i;
 
        timerlat_aa_destroy();

diff --git a/tools/tracing/rtla/src/timerlat_aa.c b/tools/tracing/rtla/src/timerlat_aa.c
index 178de60dcef907f486a0e021b1ec109d1e32f667..0954833758236393010e689e7697ba1839cf1e48 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_aa.c
+++ b/tools/tracing/rtla/src/timerlat_aa.c
@@ -1043,7 +1043,6 @@ out_ctx:
  */
 int timerlat_aa_init(struct osnoise_tool *tool, int dump_tasks, enum stack_format stack_format)
 {
-       int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
        struct timerlat_aa_context *taa_ctx;
        int retval;
 

diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 88211e54bc9d7652fa96539fe60080d447bcdb5d..3ebe41eed9f6a1ea4c481a811e7e17851d83ff65 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -1040,9 +1040,6 @@ static struct osnoise_tool
 *timerlat_init_hist(struct common_params *params)
 {
        struct osnoise_tool *tool;
-       int nr_cpus;
-
-       nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
 
        tool = osnoise_init_tool("timerlat_hist");
        if (!tool)

diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 7a00f3844f56ca59015a86af8760f22bee68f130..4105638f45c494ed04f918df5e2e97dbc17684cb 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -442,15 +442,11 @@ timerlat_print_stats(struct osnoise_tool *top)
        struct timerlat_params *params = to_timerlat_params(top->params);
        struct trace_instance *trace = &top->trace;
        struct timerlat_top_cpu summary;
-       static int nr_cpus = -1;
        int i;
 
        if (params->common.aa_only)
                return;
 
-       if (nr_cpus == -1)
-               nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
-
        if (!params->common.quiet)
                clear_terminal(trace->seq);
 
@@ -790,9 +786,6 @@ static struct osnoise_tool
 *timerlat_init_top(struct common_params *params)
 {
        struct osnoise_tool *top;
-       int nr_cpus;
-
-       nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
 
        top = osnoise_init_tool("timerlat_top");
        if (!top)

diff --git a/tools/tracing/rtla/src/timerlat_u.c b/tools/tracing/rtla/src/timerlat_u.c
index ce68e39d25fdeef892852e036606638096015685..a569fe7f93aab13c7600f389607096acbc1830d9 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_u.c
+++ b/tools/tracing/rtla/src/timerlat_u.c
@@ -16,7 +16,7 @@
 #include <sys/wait.h>
 #include <sys/prctl.h>
 
-#include "utils.h"
+#include "common.h"
 #include "timerlat_u.h"
 
 /*
@@ -131,7 +131,6 @@ static int timerlat_u_send_kill(pid_t *procs, int nr_cpus)
  */
 void *timerlat_u_dispatcher(void *data)
 {
-       int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
        struct timerlat_u_params *params = data;
        char proc_name[128];
        int procs_count = 0;

diff --git a/tools/tracing/rtla/src/timerlat_u.h b/tools/tracing/rtla/src/timerlat_u.h
index 6615119089574760fbcaf6413df2acfb77dfaad8..a692331bd1c75ffb5aca85f5519f419152518d80 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_u.h
+++ b/tools/tracing/rtla/src/timerlat_u.h
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#pragma once
 /*
  * Copyright (C) 2023 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
  */

diff --git a/tools/tracing/rtla/src/utils.c b/tools/tracing/rtla/src/utils.c
index d979159f6b70f92aa189adeab85bd0d73d3fdffa..77593718766a6c91a760918a89de0b6b5785b4fd 100644 (file)
--- a/tools/tracing/rtla/src/utils.c
+++ b/tools/tracing/rtla/src/utils.c
@@ -19,7 +19,7 @@
 #include <stdio.h>
 #include <limits.h>
 
-#include "utils.h"
+#include "common.h"
 
 #define MAX_MSG_LENGTH 1024
 int config_debug;
@@ -119,14 +119,11 @@ 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)
@@ -577,7 +574,6 @@ int save_cpu_idle_disable_state(unsigned int cpu)
        unsigned int nr_states;
        unsigned int state;
        int disabled;
-       int nr_cpus;
 
        nr_states = cpuidle_state_count(cpu);
 
@@ -585,7 +581,6 @@ int save_cpu_idle_disable_state(unsigned int cpu)
                return 0;
 
        if (saved_cpu_idle_disable_state == NULL) {
-               nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
                saved_cpu_idle_disable_state = calloc(nr_cpus, sizeof(unsigned int *));
                if (!saved_cpu_idle_disable_state)
                        return -1;
@@ -662,13 +657,10 @@ int restore_cpu_idle_disable_state(unsigned int cpu)
 void free_cpu_idle_disable_states(void)
 {
        int cpu;
-       int nr_cpus;
 
        if (!saved_cpu_idle_disable_state)
                return;
 
-       nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
-
        for (cpu = 0; cpu < nr_cpus; cpu++) {
                free(saved_cpu_idle_disable_state[cpu]);
                saved_cpu_idle_disable_state[cpu] = NULL;

diff --git a/tools/tracing/rtla/tests/unit/unit_tests.c b/tools/tracing/rtla/tests/unit/unit_tests.c
index aa53f8605e36d310cbce721ac8b23444fe8746bb..f3c6d89e3300c3b2b99c353867a792a02f74f22b 100644 (file)
--- a/tools/tracing/rtla/tests/unit/unit_tests.c
+++ b/tools/tracing/rtla/tests/unit/unit_tests.c
@@ -7,8 +7,10 @@
 #include <sched.h>
 #include <limits.h>
 #include <unistd.h>
+#include <sys/sysinfo.h>
 
 #include "../../src/utils.h"
+int nr_cpus;
 
 START_TEST(test_strtoi)
 {
@@ -34,35 +36,29 @@ END_TEST
 START_TEST(test_parse_cpu_set)
 {
        cpu_set_t set;
-       int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
 
+       nr_cpus = 8;
        ck_assert_int_eq(parse_cpu_set("0", &set), 0);
        ck_assert(CPU_ISSET(0, &set));
        ck_assert(!CPU_ISSET(1, &set));
 
-       if (nr_cpus > 2) {
-               ck_assert_int_eq(parse_cpu_set("0,2", &set), 0);
-               ck_assert(CPU_ISSET(0, &set));
-               ck_assert(CPU_ISSET(2, &set));
-       }
-
-       if (nr_cpus > 3) {
-               ck_assert_int_eq(parse_cpu_set("0-3", &set), 0);
-               ck_assert(CPU_ISSET(0, &set));
-               ck_assert(CPU_ISSET(1, &set));
-               ck_assert(CPU_ISSET(2, &set));
-               ck_assert(CPU_ISSET(3, &set));
-       }
-
-       if (nr_cpus > 5) {
-               ck_assert_int_eq(parse_cpu_set("1-3,5", &set), 0);
-               ck_assert(!CPU_ISSET(0, &set));
-               ck_assert(CPU_ISSET(1, &set));
-               ck_assert(CPU_ISSET(2, &set));
-               ck_assert(CPU_ISSET(3, &set));
-               ck_assert(!CPU_ISSET(4, &set));
-               ck_assert(CPU_ISSET(5, &set));
-       }
+       ck_assert_int_eq(parse_cpu_set("0,2", &set), 0);
+       ck_assert(CPU_ISSET(0, &set));
+       ck_assert(CPU_ISSET(2, &set));
+
+       ck_assert_int_eq(parse_cpu_set("0-3", &set), 0);
+       ck_assert(CPU_ISSET(0, &set));
+       ck_assert(CPU_ISSET(1, &set));
+       ck_assert(CPU_ISSET(2, &set));
+       ck_assert(CPU_ISSET(3, &set));
+
+       ck_assert_int_eq(parse_cpu_set("1-3,5", &set), 0);
+       ck_assert(!CPU_ISSET(0, &set));
+       ck_assert(CPU_ISSET(1, &set));
+       ck_assert(CPU_ISSET(2, &set));
+       ck_assert(CPU_ISSET(3, &set));
+       ck_assert(!CPU_ISSET(4, &set));
+       ck_assert(CPU_ISSET(5, &set));
 
        ck_assert_int_eq(parse_cpu_set("-1", &set), 1);
        ck_assert_int_eq(parse_cpu_set("abc", &set), 1);