Adding perf_evsel__open function into libperf. It's a simplified version of evsel__open without fallback stuff. We can try to merge it in the future to libperf, but it has many glitches.
Link: http://lkml.kernel.org/n/tip-l21dawds9vj61pbtqhcna...@git.kernel.org Signed-off-by: Jiri Olsa <jo...@kernel.org> --- tools/perf/lib/evsel.c | 65 +++++++++++++++++++++++++++++ tools/perf/lib/include/perf/evsel.h | 4 ++ tools/perf/lib/libperf.map | 1 + 3 files changed, 70 insertions(+) diff --git a/tools/perf/lib/evsel.c b/tools/perf/lib/evsel.c index 027f1edb4e8e..7027dacb50f6 100644 --- a/tools/perf/lib/evsel.c +++ b/tools/perf/lib/evsel.c @@ -1,11 +1,17 @@ // SPDX-License-Identifier: GPL-2.0 #include <errno.h> +#include <unistd.h> +#include <sys/syscall.h> #include <perf/evsel.h> +#include <perf/cpumap.h> +#include <perf/threadmap.h> #include <linux/list.h> #include <internal/evsel.h> #include <linux/zalloc.h> #include <stdlib.h> #include <internal/xyarray.h> +#include <internal/cpumap.h> +#include <internal/threadmap.h> #include <linux/string.h> void perf_evsel__init(struct perf_evsel *evsel, struct perf_event_attr *attr) @@ -46,3 +52,62 @@ int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads) return evsel->fd != NULL ? 0 : -ENOMEM; } + +static int +sys_perf_event_open(struct perf_event_attr *attr, + pid_t pid, int cpu, int group_fd, + unsigned long flags) +{ + return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags); +} + +int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, + struct perf_thread_map *threads) +{ + int cpu, thread, err = 0; + + if (cpus == NULL) { + static struct perf_cpu_map *empty_cpu_map; + + if (empty_cpu_map == NULL) { + empty_cpu_map = perf_cpu_map__dummy_new(); + if (empty_cpu_map == NULL) + return -ENOMEM; + } + + cpus = empty_cpu_map; + } + + if (threads == NULL) { + static struct perf_thread_map *empty_thread_map; + + if (empty_thread_map == NULL) { + empty_thread_map = perf_thread_map__new_dummy(); + if (empty_thread_map == NULL) + return -ENOMEM; + } + + threads = empty_thread_map; + } + + if (evsel->fd == NULL && + perf_evsel__alloc_fd(evsel, cpus->nr, threads->nr) < 0) + return -ENOMEM; + + for (cpu = 0; cpu < cpus->nr; cpu++) { + for (thread = 0; thread < threads->nr; thread++) { + int fd; + + fd = sys_perf_event_open(&evsel->attr, + threads->map[thread].pid, + cpus->map[cpu], -1, 0); + + if (fd < 0) + return -errno; + + FD(evsel, cpu, thread) = fd; + } + } + + return err; +} diff --git a/tools/perf/lib/include/perf/evsel.h b/tools/perf/lib/include/perf/evsel.h index c01de0752e4d..adda02f00369 100644 --- a/tools/perf/lib/include/perf/evsel.h +++ b/tools/perf/lib/include/perf/evsel.h @@ -6,10 +6,14 @@ #include <perf/core.h> struct perf_evsel; +struct perf_cpu_map; +struct perf_thread_map; LIBPERF_API void perf_evsel__init(struct perf_evsel *evsel, struct perf_event_attr *attr); LIBPERF_API struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr); LIBPERF_API void perf_evsel__delete(struct perf_evsel *evsel); +LIBPERF_API int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, + struct perf_thread_map *threads); #endif /* __LIBPERF_EVSEL_H */ diff --git a/tools/perf/lib/libperf.map b/tools/perf/lib/libperf.map index 9b6e8f165014..7594d3d89c5f 100644 --- a/tools/perf/lib/libperf.map +++ b/tools/perf/lib/libperf.map @@ -14,6 +14,7 @@ LIBPERF_0.0.1 { perf_evsel__new; perf_evsel__delete; perf_evsel__init; + perf_evsel__open; perf_evlist__new; perf_evlist__delete; perf_evlist__init; -- 2.21.0
