Turbostat: Refactor topology probing

Only probe the topology once and store in locally

diff --git a/src/turbostat.c b/src/turbostat.c
index 482ec5e15e904a65880dd2271b91dfeec891ab7c..e35f3d20dbd09048791b36c66b762d1656049b7b 100644 (file)
--- a/src/turbostat.c
+++ b/src/turbostat.c
@@ -196,21 +196,30 @@ static _Bool allocated = 0;
 static _Bool initialized = 0;
 
 #define GET_THREAD(thread_base, thread_no, core_no, pkg_no) \
-       (thread_base + (pkg_no) * topo.num_cores_per_pkg * \
-               topo.num_threads_per_core + \
-               (core_no) * topo.num_threads_per_core + (thread_no))
+       (thread_base + \
+               (pkg_no) * topology.num_cores * topology.num_threads + \
+               (core_no) * topology.num_threads + \
+               (thread_no))
 #define GET_CORE(core_base, core_no, pkg_no) \
-       (core_base + (pkg_no) * topo.num_cores_per_pkg + (core_no))
+       (core_base + \
+               (pkg_no) * topology.num_cores + \
+               (core_no))
 #define GET_PKG(pkg_base, pkg_no) (pkg_base + pkg_no)
 
-struct topo_params {
+struct cpu_topology {
+       int package_id;
+       int core_id;
+       _Bool first_core_in_package;
+       _Bool first_thread_in_core;
+};
+
+struct topology {
+       int max_cpu_id;
        int num_packages;
-       int num_cpus;
        int num_cores;
-       int max_cpu_num;
-       int num_cores_per_pkg;
-       int num_threads_per_core;
-} topo;
+       int num_threads;
+       struct cpu_topology *cpus;
+} topology;
 
 struct timeval tv_even, tv_odd, tv_delta;
 
@@ -661,14 +670,13 @@ done:
        return 0;
 }
 
+
 /**********************************
  * Looping function over all CPUs *
  **********************************/
 
 /*
  * Check if a given cpu id is in our compiled list of existing CPUs
- *
- * CHECKME: Why do we need this?
  */
 static int
 cpu_is_not_present(int cpu)
@@ -679,7 +687,7 @@ cpu_is_not_present(int cpu)
 /*
  * Loop on all CPUs in topological order
  *
- * Skip 'non-present' cpus (CHECKME: Why do we need this?)
+ * Skip non-present cpus
  * Return the error code at the first error or 0
  */
 static int __attribute__((warn_unused_result))
@@ -688,10 +696,9 @@ for_all_cpus(int (func)(struct thread_data *, struct core_data *, struct pkg_dat
 {
        int retval, pkg_no, core_no, thread_no;
 
-       for (pkg_no = 0; pkg_no < topo.num_packages; ++pkg_no) {
-               for (core_no = 0; core_no < topo.num_cores_per_pkg; ++core_no) {
-                       for (thread_no = 0; thread_no <
-                               topo.num_threads_per_core; ++thread_no) {
+       for (pkg_no = 0; pkg_no < topology.num_packages; ++pkg_no) {
+               for (core_no = 0; core_no < topology.num_cores; ++core_no) {
+                       for (thread_no = 0; thread_no < topology.num_threads; ++thread_no) {
                                struct thread_data *t;
                                struct core_data *c;
                                struct pkg_data *p;
@@ -716,6 +723,9 @@ for_all_cpus(int (func)(struct thread_data *, struct core_data *, struct pkg_dat
 /*
  * Dedicated loop: Extract every data evolution for all CPU
  *
+ * Skip non-present cpus
+ * Return the error code at the first error or 0
+ *
  * Core data is shared for all threads in one core: extracted only for the first thread
  * Package data is shared for all core in one package: extracted only for the first thread of the first core
  */
@@ -725,10 +735,9 @@ for_all_cpus_delta(const struct thread_data *thread_new_base, const struct core_
 {
        int retval, pkg_no, core_no, thread_no;
 
-       for (pkg_no = 0; pkg_no < topo.num_packages; ++pkg_no) {
-               for (core_no = 0; core_no < topo.num_cores_per_pkg; ++core_no) {
-                       for (thread_no = 0; thread_no <
-                               topo.num_threads_per_core; ++thread_no) {
+       for (pkg_no = 0; pkg_no < topology.num_packages; ++pkg_no) {
+               for (core_no = 0; core_no < topology.num_cores; ++core_no) {
+                       for (thread_no = 0; thread_no < topology.num_threads; ++thread_no) {
                                struct thread_data *t_delta;
                                const struct thread_data *t_old, *t_new;
                                struct core_data *c_delta;
@@ -821,8 +830,13 @@ free_all_buffers(void)
        package_delta = NULL;
 }
 
+
+/****************
+ * File helpers *
+ ****************/
+
 /*
- * Parse a file containing a single int.
+ * Read a single int from a file.
  */
 static int __attribute__ ((format(printf,1,2)))
 parse_int_file(const char *fmt, ...)
@@ -848,40 +862,8 @@ parse_int_file(const char *fmt, ...)
        return value;
 }
 
-/*
- * cpu_is_first_sibling_in_core(cpu)
- * return 1 if given CPU is 1st HT sibling in the core
- */
-static int
-cpu_is_first_sibling_in_core(int cpu)
-{
-       return cpu == parse_int_file("/sys/devices/system/cpu/cpu%d/topology/thread_siblings_list", cpu);
-}
-
-/*
- * cpu_is_first_core_in_package(cpu)
- * return 1 if given CPU is 1st core in package
- */
-static int
-cpu_is_first_core_in_package(int cpu)
-{
-       return cpu == parse_int_file("/sys/devices/system/cpu/cpu%d/topology/core_siblings_list", cpu);
-}
-
 static int
-get_physical_package_id(int cpu)
-{
-       return parse_int_file("/sys/devices/system/cpu/cpu%d/topology/physical_package_id", cpu);
-}
-
-static int
-get_core_id(int cpu)
-{
-       return parse_int_file("/sys/devices/system/cpu/cpu%d/topology/core_id", cpu);
-}
-
-static int
-get_num_ht_siblings(int cpu)
+get_threads_on_core(int cpu)
 {
        char path[80];
        FILE *filep;
@@ -950,18 +932,16 @@ for_all_proc_cpus(int (func)(int))
 }
 
 /*
- * count_cpus()
- * remember the last one seen, it will be the max
+ * Update the stored topology.max_cpu_id
  */
 static int
-count_cpus(int cpu)
+update_max_cpu_id(int cpu)
 {
-       if (topo.max_cpu_num < cpu)
-               topo.max_cpu_num = cpu;
-
-       topo.num_cpus += 1;
+       if (topology.max_cpu_id < cpu)
+               topology.max_cpu_id = cpu;
        return 0;
 }
+
 static int
 mark_cpu_present(int cpu)
 {
@@ -1314,229 +1294,212 @@ probe_cpu()
        return 0;
 }
 
+static int __attribute__((warn_unused_result))
+allocate_cpu_set(cpu_set_t * set, size_t * size) {
+       set = CPU_ALLOC(topology.max_cpu_id  + 1);
+       if (set == NULL) {
+               ERROR("Unable to allocate CPU state");
+               return -ERR_CPU_ALLOC;
+       }
+       *size = CPU_ALLOC_SIZE(topology.max_cpu_id  + 1);
+       CPU_ZERO_S(*size, set);
+       return 0;
+}
 
-
+/*
+ * Build a local representation of the cpu distribution
+ */
 static int __attribute__((warn_unused_result))
 topology_probe()
 {
        int i;
        int ret;
-       int max_core_id = 0;
-       int max_package_id = 0;
-       int max_siblings = 0;
-       struct cpu_topology {
-               int core_id;
-               int physical_package_id;
-       } *cpus;
-
-       /* Initialize num_cpus, max_cpu_num */
-       topo.num_cpus = 0;
-       topo.max_cpu_num = 0;
-       ret = for_all_proc_cpus(count_cpus);
-       if (ret < 0)
-               return ret;
-
-       DEBUG("num_cpus %d max_cpu_num %d\n", topo.num_cpus, topo.max_cpu_num);
-
-       cpus = calloc(1, (topo.max_cpu_num  + 1) * sizeof(struct cpu_topology));
-       if (cpus == NULL) {
-               ERROR("calloc cpus");
-               return -ERR_CALLOC;
-       }
+       int max_package_id, max_core_id, max_thread_id;
+       max_package_id = max_core_id = max_thread_id = 0;
 
-       /*
-        * Allocate and initialize cpu_present_set
-        */
-       cpu_present_set = CPU_ALLOC((topo.max_cpu_num + 1));
-       if (cpu_present_set == NULL) {
-               free(cpus);
-               ERROR("CPU_ALLOC");
-               return -ERR_CPU_ALLOC;
-       }
-       cpu_present_setsize = CPU_ALLOC_SIZE((topo.max_cpu_num + 1));
-       CPU_ZERO_S(cpu_present_setsize, cpu_present_set);
-       ret = for_all_proc_cpus(mark_cpu_present);
-       if (ret < 0) {
-               free(cpus);
-               return ret;
-       }
-
-       /*
-        * Allocate and initialize cpu_affinity_set
-        */
-       cpu_affinity_set = CPU_ALLOC((topo.max_cpu_num + 1));
-       if (cpu_affinity_set == NULL) {
-               free(cpus);
-               ERROR("CPU_ALLOC");
-               return -ERR_CPU_ALLOC;
-       }
-       cpu_affinity_setsize = CPU_ALLOC_SIZE((topo.max_cpu_num + 1));
-       CPU_ZERO_S(cpu_affinity_setsize, cpu_affinity_set);
+       /* Clean topology */
+       free(topology.cpus);
+       memset(&topology, 0, sizeof(topology));
 
+       /* Can't fail (update_max_cpu_id always returns 0) */
+       assert(for_all_proc_cpus(update_max_cpu_id));
 
-       /*
-        * Allocate and initialize cpu_saved_affinity_set
-        */
-       cpu_saved_affinity_set = CPU_ALLOC((topo.max_cpu_num + 1));
-       if (cpu_saved_affinity_set == NULL) {
-               free(cpus);
-               ERROR("CPU_ALLOC");
-               return -ERR_CPU_ALLOC;
+       topology.cpus = calloc(1, (topology.max_cpu_id  + 1) * sizeof(struct cpu_topology));
+       if (topology.cpus == NULL) {
+               ERROR("Unable to allocate memory for cpu topology");
+               return -ERR_CALLOC;
        }
-       cpu_saved_affinity_setsize = CPU_ALLOC_SIZE((topo.max_cpu_num + 1));
-       CPU_ZERO_S(cpu_saved_affinity_setsize, cpu_saved_affinity_set);
 
+       ret = allocate_cpu_set(cpu_present_set, &cpu_present_setsize);
+       if (ret != 0)
+               goto err;
+       ret = allocate_cpu_set(cpu_affinity_set, &cpu_affinity_setsize);
+       if (ret != 0)
+               goto err;
+       ret = allocate_cpu_set(cpu_saved_affinity_set, &cpu_saved_affinity_setsize);
+       if (ret != 0)
+               goto err;
+
+       /* Can't fail (mark_cpu_present always returns 0) */
+       assert(for_all_proc_cpus(mark_cpu_present));
 
        /*
         * For online cpus
         * find max_core_id, max_package_id
         */
-       for (i = 0; i <= topo.max_cpu_num; ++i) {
-               int siblings;
+       for (i = 0; i <= topology.max_cpu_id; ++i) {
+               int num_threads;
+               struct cpu_topology *cpu = &topology.cpus[i];
 
                if (cpu_is_not_present(i)) {
                        WARNING("cpu%d NOT PRESENT", i);
                        continue;
                }
-               cpus[i].core_id = get_core_id(i);
-               if (cpus[i].core_id < 0)
-                       return cpus[i].core_id;
-               if (cpus[i].core_id > max_core_id)
-                       max_core_id = cpus[i].core_id;
-
-               cpus[i].physical_package_id = get_physical_package_id(i);
-               if (cpus[i].physical_package_id < 0)
-                       return cpus[i].physical_package_id;
-               if (cpus[i].physical_package_id > max_package_id)
-                       max_package_id = cpus[i].physical_package_id;
-
-               siblings = get_num_ht_siblings(i);
-               if (siblings < 0)
-                       return siblings;
-               if (siblings > max_siblings)
-                       max_siblings = siblings;
-               DEBUG("cpu %d pkg %d core %d\n",
-                       i, cpus[i].physical_package_id, cpus[i].core_id);
-       }
-       topo.num_cores_per_pkg = max_core_id + 1;
-       DEBUG("max_core_id %d, sizing for %d cores per package\n",
-               max_core_id, topo.num_cores_per_pkg);
 
-       topo.num_packages = max_package_id + 1;
-       DEBUG("max_package_id %d, sizing for %d packages\n",
-               max_package_id, topo.num_packages);
+               ret = parse_int_file("/sys/devices/system/cpu/cpu%d/topology/physical_package_id", i);
+               if (ret < 0)
+                       goto err;
+               else
+                       cpu->package_id = ret;
+               if (cpu->package_id > max_package_id)
+                       max_package_id = cpu->package_id;
 
-       topo.num_threads_per_core = max_siblings;
-       DEBUG("max_siblings %d\n", max_siblings);
+               ret = parse_int_file("/sys/devices/system/cpu/cpu%d/topology/core_id", i);
+               if (ret < 0)
+                       goto err;
+               else
+                       cpu->core_id = ret;
+               if (cpu->core_id > max_core_id)
+                       max_core_id = cpu->core_id;
+               ret = parse_int_file("/sys/devices/system/cpu/cpu%d/topology/core_siblings_list", i);
+               if (ret < 0)
+                       goto err;
+               else if (ret == cpu->core_id)
+                       cpu->first_core_in_package = 1;
+
+               ret = get_threads_on_core(i);
+               if (ret < 0)
+                       goto err;
+               else
+                       num_threads = ret;
+               if (num_threads > max_thread_id)
+                       max_thread_id = num_threads;
+               if (num_threads > 1) {
+                       ret = parse_int_file("/sys/devices/system/cpu/cpu%d/topology/thread_siblings_list", i);
+                       if (ret < 0)
+                               goto err;
+                       else if (ret == num_threads)
+                               cpu->first_thread_in_core = 1;
+               }
+               DEBUG("cpu %d pkg %d core %d\n",
+                       i, cpu->package_id, cpu->core_id);
+       }
+       /* Num is max + 1 (need to count 0) */
+       topology.num_packages = max_package_id + 1;
+       topology.num_cores = max_core_id + 1;
+       topology.num_threads = max_thread_id + 1;
 
-       free(cpus);
        return 0;
+err:
+       free(topology.cpus);
+       return ret;
 }
 
 static int
-allocate_counters(struct thread_data **t, struct core_data **c, struct pkg_data **p)
+allocate_counters(struct thread_data **threads, struct core_data **cores, struct pkg_data **packages)
 {
        int i;
+       int total_threads, total_cores;
 
-       *t = calloc(topo.num_threads_per_core * topo.num_cores_per_pkg *
-               topo.num_packages, sizeof(struct thread_data));
-       if (*t == NULL)
-               goto error;
+       total_threads = topology.num_threads * topology.num_cores * topology.num_packages;
+       *threads = calloc(total_threads, sizeof(struct thread_data));
+       if (*threads == NULL)
+               goto err;
 
-       for (i = 0; i < topo.num_threads_per_core *
-               topo.num_cores_per_pkg * topo.num_packages; i++)
-               (*t)[i].cpu_id = -1;
+       for (i = 0; i < total_threads; ++i)
+               (*threads)[i].cpu_id = -1;
 
-       *c = calloc(topo.num_cores_per_pkg * topo.num_packages,
-               sizeof(struct core_data));
-       if (*c == NULL)
-               goto error;
+       total_cores = topology.num_cores * topology.num_packages;
+       *cores = calloc(total_cores, sizeof(struct core_data));
+       if (*cores == NULL)
+               goto err_clean_threads;
 
-       for (i = 0; i < topo.num_cores_per_pkg * topo.num_packages; i++)
-               (*c)[i].core_id = -1;
+       for (i = 0; i < total_cores; ++i)
+               (*cores)[i].core_id = -1;
 
-       *p = calloc(topo.num_packages, sizeof(struct pkg_data));
-       if (*p == NULL)
-               goto error;
+       *packages = calloc(topology.num_packages, sizeof(struct pkg_data));
+       if (*packages == NULL)
+               goto err_clean_cores;
 
-       for (i = 0; i < topo.num_packages; i++)
-               (*p)[i].package_id = i;
+       for (i = 0; i < topology.num_packages; i++)
+               (*packages)[i].package_id = i;
 
        return 0;
-error:
+
+err_clean_cores:
+       free(*cores);
+err_clean_threads:
+       free(*threads);
+err:
        ERROR("calloc counters");
        return -ERR_CALLOC;
 }
+
 /*
  * init_counter()
  *
- * set cpu_id, core_num, pkg_num
+ * set cpu_id, core_id, package_id
  * set FIRST_THREAD_IN_CORE and FIRST_CORE_IN_PACKAGE
  *
  * increment topo.num_cores when 1st core in pkg seen
  */
 static int
 init_counter(struct thread_data *thread_base, struct core_data *core_base,
-       struct pkg_data *pkg_base, int thread_num, int core_num,
-       int pkg_num, int cpu_id)
+       struct pkg_data *pkg_base, int cpu_id)
 {
-       int ret;
        struct thread_data *t;
        struct core_data *c;
        struct pkg_data *p;
+       struct cpu_topology *cpu = &topology.cpus[cpu_id];
 
-       t = GET_THREAD(thread_base, thread_num, core_num, pkg_num);
-       c = GET_CORE(core_base, core_num, pkg_num);
-       p = GET_PKG(pkg_base, pkg_num);
+       t = GET_THREAD(thread_base, !(cpu->first_thread_in_core), cpu->core_id, cpu->package_id);
+       c = GET_CORE(core_base, cpu->core_id, cpu->package_id);
+       p = GET_PKG(pkg_base, cpu->package_id);
 
        t->cpu_id = cpu_id;
-       if (thread_num == 0) {
+       if (cpu->first_thread_in_core)
                t->flags |= CPU_IS_FIRST_THREAD_IN_CORE;
-               if ((ret = cpu_is_first_core_in_package(cpu_id)) < 0) {
-                       return ret;
-               } else if (ret != 0) {
-                       t->flags |= CPU_IS_FIRST_CORE_IN_PACKAGE;
-               }
-       }
+       if (cpu->first_core_in_package)
+               t->flags |= CPU_IS_FIRST_CORE_IN_PACKAGE;
 
-       c->core_id = core_num;
-       p->package_id = pkg_num;
+       c->core_id = cpu->core_id;
+       p->package_id = cpu->package_id;
 
        return 0;
 }
 
 
 static int
-initialize_counters(int cpu_id)
+initialize_counters(void)
 {
-       int my_thread_id, my_core_id, my_package_id;
        int ret;
+       int cpu_id;
 
-       my_package_id = get_physical_package_id(cpu_id);
-       if (my_package_id < 0)
-               return my_package_id;
-       my_core_id = get_core_id(cpu_id);
-       if (my_core_id < 0)
-               return my_core_id;
-
-       if ((ret = cpu_is_first_sibling_in_core(cpu_id)) < 0) {
-               return ret;
-       } else if (ret != 0) {
-               my_thread_id = 0;
-               topo.num_cores++;
-       } else {
-               my_thread_id = 1;
-       }
+       for (cpu_id = 0; cpu_id <= topology.max_cpu_id; ++cpu_id) {
+               if (cpu_is_not_present(cpu_id)) {
+                       continue;
+               }
 
-       ret = init_counter(EVEN_COUNTERS, my_thread_id, my_core_id, my_package_id, cpu_id);
-       if (ret < 0)
-               return ret;
-       ret = init_counter(ODD_COUNTERS, my_thread_id, my_core_id, my_package_id, cpu_id);
-       if (ret < 0)
-               return ret;
-       ret = init_counter(DELTA_COUNTERS, my_thread_id, my_core_id, my_package_id, cpu_id);
-       if (ret < 0)
-               return ret;
+               ret = init_counter(EVEN_COUNTERS, cpu_id);
+               if (ret < 0)
+                       return ret;
+               ret = init_counter(ODD_COUNTERS, cpu_id);
+               if (ret < 0)
+                       return ret;
+               ret = init_counter(DELTA_COUNTERS, cpu_id);
+               if (ret < 0)
+                       return ret;
+       }
        return 0;
 }
 
@@ -1555,7 +1518,7 @@ static int setup_all_buffers(void)
        DO_OR_GOTO_ERR(allocate_counters(&thread_even, &core_even, &package_even));
        DO_OR_GOTO_ERR(allocate_counters(&thread_odd, &core_odd, &package_odd));
        DO_OR_GOTO_ERR(allocate_counters(&thread_delta, &core_delta, &package_delta));
-       DO_OR_GOTO_ERR(for_all_proc_cpus(initialize_counters));
+       DO_OR_GOTO_ERR(initialize_counters());
        DO_OR_GOTO_ERR(for_all_cpus(set_temperature_target, EVEN_COUNTERS));
        DO_OR_GOTO_ERR(for_all_cpus(set_temperature_target, ODD_COUNTERS));