From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- tools/perf/util/perf_api_probe.c | 197 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 197 insertions(+) create mode 100644 tools/perf/util/perf_api_probe.c (limited to 'tools/perf/util/perf_api_probe.c') diff --git a/tools/perf/util/perf_api_probe.c b/tools/perf/util/perf_api_probe.c new file mode 100644 index 0000000000..e1e2d70159 --- /dev/null +++ b/tools/perf/util/perf_api_probe.c @@ -0,0 +1,197 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include "perf-sys.h" +#include "util/cloexec.h" +#include "util/evlist.h" +#include "util/evsel.h" +#include "util/parse-events.h" +#include "util/perf_api_probe.h" +#include +#include + +typedef void (*setup_probe_fn_t)(struct evsel *evsel); + +static int perf_do_probe_api(setup_probe_fn_t fn, struct perf_cpu cpu, const char *str) +{ + struct evlist *evlist; + struct evsel *evsel; + unsigned long flags = perf_event_open_cloexec_flag(); + int err = -EAGAIN, fd; + static pid_t pid = -1; + + evlist = evlist__new(); + if (!evlist) + return -ENOMEM; + + if (parse_event(evlist, str)) + goto out_delete; + + evsel = evlist__first(evlist); + + while (1) { + fd = sys_perf_event_open(&evsel->core.attr, pid, cpu.cpu, -1, flags); + if (fd < 0) { + if (pid == -1 && errno == EACCES) { + pid = 0; + continue; + } + goto out_delete; + } + break; + } + close(fd); + + fn(evsel); + + fd = sys_perf_event_open(&evsel->core.attr, pid, cpu.cpu, -1, flags); + if (fd < 0) { + if (errno == EINVAL) + err = -EINVAL; + goto out_delete; + } + close(fd); + err = 0; + +out_delete: + evlist__delete(evlist); + return err; +} + +static bool perf_probe_api(setup_probe_fn_t fn) +{ + const char *try[] = {"cycles:u", "instructions:u", "cpu-clock:u", NULL}; + struct perf_cpu_map *cpus; + struct perf_cpu cpu; + int ret, i = 0; + + cpus = perf_cpu_map__new(NULL); + if (!cpus) + return false; + cpu = perf_cpu_map__cpu(cpus, 0); + perf_cpu_map__put(cpus); + + do { + ret = perf_do_probe_api(fn, cpu, try[i++]); + if (!ret) + return true; + } while (ret == -EAGAIN && try[i]); + + return false; +} + +static void perf_probe_sample_identifier(struct evsel *evsel) +{ + evsel->core.attr.sample_type |= PERF_SAMPLE_IDENTIFIER; +} + +static void perf_probe_comm_exec(struct evsel *evsel) +{ + evsel->core.attr.comm_exec = 1; +} + +static void perf_probe_context_switch(struct evsel *evsel) +{ + evsel->core.attr.context_switch = 1; +} + +static void perf_probe_text_poke(struct evsel *evsel) +{ + evsel->core.attr.text_poke = 1; +} + +static void perf_probe_build_id(struct evsel *evsel) +{ + evsel->core.attr.build_id = 1; +} + +static void perf_probe_cgroup(struct evsel *evsel) +{ + evsel->core.attr.cgroup = 1; +} + +bool perf_can_sample_identifier(void) +{ + return perf_probe_api(perf_probe_sample_identifier); +} + +bool perf_can_comm_exec(void) +{ + return perf_probe_api(perf_probe_comm_exec); +} + +bool perf_can_record_switch_events(void) +{ + return perf_probe_api(perf_probe_context_switch); +} + +bool perf_can_record_text_poke_events(void) +{ + return perf_probe_api(perf_probe_text_poke); +} + +bool perf_can_record_cpu_wide(void) +{ + struct perf_event_attr attr = { + .type = PERF_TYPE_SOFTWARE, + .config = PERF_COUNT_SW_CPU_CLOCK, + .exclude_kernel = 1, + }; + struct perf_cpu_map *cpus; + struct perf_cpu cpu; + int fd; + + cpus = perf_cpu_map__new(NULL); + if (!cpus) + return false; + + cpu = perf_cpu_map__cpu(cpus, 0); + perf_cpu_map__put(cpus); + + fd = sys_perf_event_open(&attr, -1, cpu.cpu, -1, 0); + if (fd < 0) + return false; + close(fd); + + return true; +} + +/* + * Architectures are expected to know if AUX area sampling is supported by the + * hardware. Here we check for kernel support. + */ +bool perf_can_aux_sample(void) +{ + struct perf_event_attr attr = { + .size = sizeof(struct perf_event_attr), + .exclude_kernel = 1, + /* + * Non-zero value causes the kernel to calculate the effective + * attribute size up to that byte. + */ + .aux_sample_size = 1, + }; + int fd; + + fd = sys_perf_event_open(&attr, -1, 0, -1, 0); + /* + * If the kernel attribute is big enough to contain aux_sample_size + * then we assume that it is supported. We are relying on the kernel to + * validate the attribute size before anything else that could be wrong. + */ + if (fd < 0 && errno == E2BIG) + return false; + if (fd >= 0) + close(fd); + + return true; +} + +bool perf_can_record_build_id(void) +{ + return perf_probe_api(perf_probe_build_id); +} + +bool perf_can_record_cgroup(void) +{ + return perf_probe_api(perf_probe_cgroup); +} -- cgit v1.2.3