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perf_cpu_map__merge() will reuse one of its arguments if they are equal or the other argument is NULL. The arguments could be reused if it is known one set of values is a subset of the other. For example, a map of 0-1 and a map of just 0 when merged yields the map of 0-1. Currently a new map is created rather than adding a reference count to the original 0-1 map. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Antonov <alexander.antonov@linux.intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: German Gomez <german.gomez@arm.com> Cc: James Clark <james.clark@arm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: John Garry <john.garry@huawei.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Leach <mike.leach@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Riccardo Mancini <rickyman7@gmail.com> Cc: Song Liu <songliubraving@fb.com> Cc: Stephane Eranian <eranian@google.com> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Yonghong Song <yhs@fb.com> Cc: bpf@vger.kernel.org Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Cc: netdev@vger.kernel.org Link: http://lore.kernel.org/lkml/20220328232648.2127340-5-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
393 lines
8.1 KiB
C
393 lines
8.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <perf/cpumap.h>
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#include <stdlib.h>
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#include <linux/refcount.h>
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#include <internal/cpumap.h>
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#include <asm/bug.h>
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#include <stdio.h>
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#include <string.h>
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#include <unistd.h>
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#include <ctype.h>
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#include <limits.h>
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static struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
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{
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struct perf_cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus);
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if (cpus != NULL) {
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cpus->nr = nr_cpus;
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refcount_set(&cpus->refcnt, 1);
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}
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return cpus;
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}
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struct perf_cpu_map *perf_cpu_map__dummy_new(void)
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{
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struct perf_cpu_map *cpus = perf_cpu_map__alloc(1);
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if (cpus)
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cpus->map[0].cpu = -1;
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return cpus;
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}
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static void cpu_map__delete(struct perf_cpu_map *map)
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{
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if (map) {
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WARN_ONCE(refcount_read(&map->refcnt) != 0,
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"cpu_map refcnt unbalanced\n");
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free(map);
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}
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}
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struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map)
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{
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if (map)
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refcount_inc(&map->refcnt);
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return map;
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}
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void perf_cpu_map__put(struct perf_cpu_map *map)
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{
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if (map && refcount_dec_and_test(&map->refcnt))
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cpu_map__delete(map);
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}
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static struct perf_cpu_map *cpu_map__default_new(void)
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{
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struct perf_cpu_map *cpus;
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int nr_cpus;
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nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
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if (nr_cpus < 0)
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return NULL;
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cpus = perf_cpu_map__alloc(nr_cpus);
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if (cpus != NULL) {
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int i;
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for (i = 0; i < nr_cpus; ++i)
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cpus->map[i].cpu = i;
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}
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return cpus;
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}
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struct perf_cpu_map *perf_cpu_map__default_new(void)
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{
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return cpu_map__default_new();
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}
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static int cmp_cpu(const void *a, const void *b)
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{
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const struct perf_cpu *cpu_a = a, *cpu_b = b;
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return cpu_a->cpu - cpu_b->cpu;
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}
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static struct perf_cpu_map *cpu_map__trim_new(int nr_cpus, const struct perf_cpu *tmp_cpus)
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{
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size_t payload_size = nr_cpus * sizeof(struct perf_cpu);
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struct perf_cpu_map *cpus = perf_cpu_map__alloc(nr_cpus);
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int i, j;
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if (cpus != NULL) {
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memcpy(cpus->map, tmp_cpus, payload_size);
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qsort(cpus->map, nr_cpus, sizeof(struct perf_cpu), cmp_cpu);
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/* Remove dups */
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j = 0;
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for (i = 0; i < nr_cpus; i++) {
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if (i == 0 || cpus->map[i].cpu != cpus->map[i - 1].cpu)
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cpus->map[j++].cpu = cpus->map[i].cpu;
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}
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cpus->nr = j;
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assert(j <= nr_cpus);
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}
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return cpus;
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}
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struct perf_cpu_map *perf_cpu_map__read(FILE *file)
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{
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struct perf_cpu_map *cpus = NULL;
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int nr_cpus = 0;
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struct perf_cpu *tmp_cpus = NULL, *tmp;
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int max_entries = 0;
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int n, cpu, prev;
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char sep;
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sep = 0;
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prev = -1;
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for (;;) {
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n = fscanf(file, "%u%c", &cpu, &sep);
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if (n <= 0)
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break;
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if (prev >= 0) {
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int new_max = nr_cpus + cpu - prev - 1;
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WARN_ONCE(new_max >= MAX_NR_CPUS, "Perf can support %d CPUs. "
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"Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS);
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if (new_max >= max_entries) {
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max_entries = new_max + MAX_NR_CPUS / 2;
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tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
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if (tmp == NULL)
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goto out_free_tmp;
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tmp_cpus = tmp;
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}
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while (++prev < cpu)
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tmp_cpus[nr_cpus++].cpu = prev;
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}
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if (nr_cpus == max_entries) {
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max_entries += MAX_NR_CPUS;
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tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
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if (tmp == NULL)
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goto out_free_tmp;
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tmp_cpus = tmp;
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}
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tmp_cpus[nr_cpus++].cpu = cpu;
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if (n == 2 && sep == '-')
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prev = cpu;
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else
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prev = -1;
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if (n == 1 || sep == '\n')
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break;
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}
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if (nr_cpus > 0)
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cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
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else
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cpus = cpu_map__default_new();
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out_free_tmp:
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free(tmp_cpus);
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return cpus;
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}
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static struct perf_cpu_map *cpu_map__read_all_cpu_map(void)
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{
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struct perf_cpu_map *cpus = NULL;
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FILE *onlnf;
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onlnf = fopen("/sys/devices/system/cpu/online", "r");
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if (!onlnf)
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return cpu_map__default_new();
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cpus = perf_cpu_map__read(onlnf);
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fclose(onlnf);
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return cpus;
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}
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struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list)
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{
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struct perf_cpu_map *cpus = NULL;
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unsigned long start_cpu, end_cpu = 0;
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char *p = NULL;
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int i, nr_cpus = 0;
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struct perf_cpu *tmp_cpus = NULL, *tmp;
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int max_entries = 0;
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if (!cpu_list)
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return cpu_map__read_all_cpu_map();
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/*
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* must handle the case of empty cpumap to cover
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* TOPOLOGY header for NUMA nodes with no CPU
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* ( e.g., because of CPU hotplug)
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*/
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if (!isdigit(*cpu_list) && *cpu_list != '\0')
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goto out;
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while (isdigit(*cpu_list)) {
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p = NULL;
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start_cpu = strtoul(cpu_list, &p, 0);
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if (start_cpu >= INT_MAX
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|| (*p != '\0' && *p != ',' && *p != '-'))
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goto invalid;
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if (*p == '-') {
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cpu_list = ++p;
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p = NULL;
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end_cpu = strtoul(cpu_list, &p, 0);
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if (end_cpu >= INT_MAX || (*p != '\0' && *p != ','))
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goto invalid;
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if (end_cpu < start_cpu)
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goto invalid;
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} else {
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end_cpu = start_cpu;
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}
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WARN_ONCE(end_cpu >= MAX_NR_CPUS, "Perf can support %d CPUs. "
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"Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS);
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for (; start_cpu <= end_cpu; start_cpu++) {
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/* check for duplicates */
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for (i = 0; i < nr_cpus; i++)
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if (tmp_cpus[i].cpu == (int)start_cpu)
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goto invalid;
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if (nr_cpus == max_entries) {
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max_entries += MAX_NR_CPUS;
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tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
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if (tmp == NULL)
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goto invalid;
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tmp_cpus = tmp;
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}
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tmp_cpus[nr_cpus++].cpu = (int)start_cpu;
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}
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if (*p)
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++p;
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cpu_list = p;
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}
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if (nr_cpus > 0)
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cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
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else if (*cpu_list != '\0')
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cpus = cpu_map__default_new();
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else
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cpus = perf_cpu_map__dummy_new();
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invalid:
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free(tmp_cpus);
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out:
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return cpus;
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}
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struct perf_cpu perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
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{
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struct perf_cpu result = {
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.cpu = -1
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};
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if (cpus && idx < cpus->nr)
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return cpus->map[idx];
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return result;
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}
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int perf_cpu_map__nr(const struct perf_cpu_map *cpus)
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{
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return cpus ? cpus->nr : 1;
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}
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bool perf_cpu_map__empty(const struct perf_cpu_map *map)
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{
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return map ? map->map[0].cpu == -1 : true;
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}
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int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
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{
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int low, high;
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if (!cpus)
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return -1;
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low = 0;
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high = cpus->nr;
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while (low < high) {
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int idx = (low + high) / 2;
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struct perf_cpu cpu_at_idx = cpus->map[idx];
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if (cpu_at_idx.cpu == cpu.cpu)
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return idx;
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if (cpu_at_idx.cpu > cpu.cpu)
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high = idx;
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else
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low = idx + 1;
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}
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return -1;
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}
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bool perf_cpu_map__has(const struct perf_cpu_map *cpus, struct perf_cpu cpu)
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{
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return perf_cpu_map__idx(cpus, cpu) != -1;
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}
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struct perf_cpu perf_cpu_map__max(struct perf_cpu_map *map)
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{
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struct perf_cpu result = {
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.cpu = -1
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};
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// cpu_map__trim_new() qsort()s it, cpu_map__default_new() sorts it as well.
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return map->nr > 0 ? map->map[map->nr - 1] : result;
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}
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/** Is 'b' a subset of 'a'. */
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bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu_map *b)
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{
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if (a == b || !b)
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return true;
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if (!a || b->nr > a->nr)
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return false;
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for (int i = 0, j = 0; i < a->nr; i++) {
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if (a->map[i].cpu > b->map[j].cpu)
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return false;
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if (a->map[i].cpu == b->map[j].cpu) {
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j++;
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if (j == b->nr)
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return true;
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}
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}
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return false;
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}
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/*
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* Merge two cpumaps
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*
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* orig either gets freed and replaced with a new map, or reused
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* with no reference count change (similar to "realloc")
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* other has its reference count increased.
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*/
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struct perf_cpu_map *perf_cpu_map__merge(struct perf_cpu_map *orig,
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struct perf_cpu_map *other)
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{
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struct perf_cpu *tmp_cpus;
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int tmp_len;
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int i, j, k;
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struct perf_cpu_map *merged;
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if (perf_cpu_map__is_subset(orig, other))
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return orig;
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if (perf_cpu_map__is_subset(other, orig)) {
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perf_cpu_map__put(orig);
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return perf_cpu_map__get(other);
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}
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tmp_len = orig->nr + other->nr;
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tmp_cpus = malloc(tmp_len * sizeof(struct perf_cpu));
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if (!tmp_cpus)
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return NULL;
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/* Standard merge algorithm from wikipedia */
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i = j = k = 0;
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while (i < orig->nr && j < other->nr) {
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if (orig->map[i].cpu <= other->map[j].cpu) {
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if (orig->map[i].cpu == other->map[j].cpu)
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j++;
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tmp_cpus[k++] = orig->map[i++];
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} else
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tmp_cpus[k++] = other->map[j++];
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}
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while (i < orig->nr)
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tmp_cpus[k++] = orig->map[i++];
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while (j < other->nr)
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tmp_cpus[k++] = other->map[j++];
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assert(k <= tmp_len);
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merged = cpu_map__trim_new(k, tmp_cpus);
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free(tmp_cpus);
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perf_cpu_map__put(orig);
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return merged;
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}
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