From d1a177595b3a824c72dacb0f9d1a4e5906eaef0e Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Mon, 7 Oct 2019 14:53:21 +0200 Subject: [PATCH] libperf: Adopt perf_evlist__mmap()/munmap() from tools/perf Add libperf's version of perf_evlist__mmap()/munmap() functions and exporting them in the perf/evlist.h header. It's the backbone of what we have in perf code. The following changes will add needed callbacks and then we'll finally switch the perf code to use libperf's version. Add mmap/mmap_ovw 'struct perf_mmap' object arrays to hold maps for libperf's evlist. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20191007125344.14268-14-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/lib/evlist.c | 236 +++++++++++++++++++++++ tools/perf/lib/include/internal/evlist.h | 2 + tools/perf/lib/include/perf/evlist.h | 3 + tools/perf/lib/libperf.map | 2 + 4 files changed, 243 insertions(+) diff --git a/tools/perf/lib/evlist.c b/tools/perf/lib/evlist.c index d1496fee810c..250ad5752589 100644 --- a/tools/perf/lib/evlist.c +++ b/tools/perf/lib/evlist.c @@ -8,13 +8,20 @@ #include #include #include +#include +#include +#include +#include +#include #include +#include #include #include #include #include #include #include +#include #include #include #include @@ -103,6 +110,10 @@ perf_evlist__next(struct perf_evlist *evlist, struct perf_evsel *prev) void perf_evlist__delete(struct perf_evlist *evlist) { + if (evlist == NULL) + return; + + perf_evlist__munmap(evlist); free(evlist); } @@ -281,3 +292,228 @@ int perf_evlist__poll(struct perf_evlist *evlist, int timeout) { return fdarray__poll(&evlist->pollfd, timeout); } + +static struct perf_mmap* perf_evlist__alloc_mmap(struct perf_evlist *evlist, bool overwrite) +{ + int i; + struct perf_mmap *map; + + evlist->nr_mmaps = perf_cpu_map__nr(evlist->cpus); + if (perf_cpu_map__empty(evlist->cpus)) + evlist->nr_mmaps = perf_thread_map__nr(evlist->threads); + + map = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap)); + if (!map) + return NULL; + + for (i = 0; i < evlist->nr_mmaps; i++) { + /* + * When the perf_mmap() call is made we grab one refcount, plus + * one extra to let perf_mmap__consume() get the last + * events after all real references (perf_mmap__get()) are + * dropped. + * + * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and + * thus does perf_mmap__get() on it. + */ + perf_mmap__init(&map[i], overwrite, NULL); + } + + return map; +} + +static void perf_evlist__set_sid_idx(struct perf_evlist *evlist, + struct perf_evsel *evsel, int idx, int cpu, + int thread) +{ + struct perf_sample_id *sid = SID(evsel, cpu, thread); + + sid->idx = idx; + if (evlist->cpus && cpu >= 0) + sid->cpu = evlist->cpus->map[cpu]; + else + sid->cpu = -1; + if (!evsel->system_wide && evlist->threads && thread >= 0) + sid->tid = perf_thread_map__pid(evlist->threads, thread); + else + sid->tid = -1; +} + +static struct perf_mmap* +perf_evlist__map_get(struct perf_evlist *evlist, bool overwrite, int idx) +{ + struct perf_mmap *map = &evlist->mmap[idx]; + + if (overwrite) { + if (!evlist->mmap_ovw) { + evlist->mmap_ovw = perf_evlist__alloc_mmap(evlist, true); + if (!evlist->mmap_ovw) + return NULL; + } + map = &evlist->mmap_ovw[idx]; + } + + return map; +} + +#define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y)) + +static int +mmap_per_evsel(struct perf_evlist *evlist, int idx, + struct perf_mmap_param *mp, int cpu_idx, + int thread, int *_output, int *_output_overwrite) +{ + int evlist_cpu = perf_cpu_map__cpu(evlist->cpus, cpu_idx); + struct perf_evsel *evsel; + int revent; + + perf_evlist__for_each_entry(evlist, evsel) { + bool overwrite = evsel->attr.write_backward; + struct perf_mmap *map; + int *output, fd, cpu; + + if (evsel->system_wide && thread) + continue; + + cpu = perf_cpu_map__idx(evsel->cpus, evlist_cpu); + if (cpu == -1) + continue; + + map = perf_evlist__map_get(evlist, overwrite, idx); + if (map == NULL) + return -ENOMEM; + + if (overwrite) { + mp->prot = PROT_READ; + output = _output_overwrite; + } else { + mp->prot = PROT_READ | PROT_WRITE; + output = _output; + } + + fd = FD(evsel, cpu, thread); + + if (*output == -1) { + *output = fd; + + if (perf_mmap__mmap(map, mp, *output, evlist_cpu) < 0) + return -1; + } else { + if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0) + return -1; + + perf_mmap__get(map); + } + + revent = !overwrite ? POLLIN : 0; + + if (!evsel->system_wide && + perf_evlist__add_pollfd(evlist, fd, map, revent) < 0) { + perf_mmap__put(map); + return -1; + } + + if (evsel->attr.read_format & PERF_FORMAT_ID) { + if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread, + fd) < 0) + return -1; + perf_evlist__set_sid_idx(evlist, evsel, idx, cpu, + thread); + } + } + + return 0; +} + +static int +mmap_per_thread(struct perf_evlist *evlist, struct perf_mmap_param *mp) +{ + int thread; + int nr_threads = perf_thread_map__nr(evlist->threads); + + for (thread = 0; thread < nr_threads; thread++) { + int output = -1; + int output_overwrite = -1; + + if (mmap_per_evsel(evlist, thread, mp, 0, thread, + &output, &output_overwrite)) + goto out_unmap; + } + + return 0; + +out_unmap: + perf_evlist__munmap(evlist); + return -1; +} + +static int +mmap_per_cpu(struct perf_evlist *evlist, struct perf_mmap_param *mp) +{ + int nr_threads = perf_thread_map__nr(evlist->threads); + int nr_cpus = perf_cpu_map__nr(evlist->cpus); + int cpu, thread; + + for (cpu = 0; cpu < nr_cpus; cpu++) { + int output = -1; + int output_overwrite = -1; + + for (thread = 0; thread < nr_threads; thread++) { + if (mmap_per_evsel(evlist, cpu, mp, cpu, + thread, &output, &output_overwrite)) + goto out_unmap; + } + } + + return 0; + +out_unmap: + perf_evlist__munmap(evlist); + return -1; +} + +int perf_evlist__mmap(struct perf_evlist *evlist, int pages) +{ + struct perf_evsel *evsel; + const struct perf_cpu_map *cpus = evlist->cpus; + const struct perf_thread_map *threads = evlist->threads; + struct perf_mmap_param mp; + + if (!evlist->mmap) + evlist->mmap = perf_evlist__alloc_mmap(evlist, false); + if (!evlist->mmap) + return -ENOMEM; + + perf_evlist__for_each_entry(evlist, evsel) { + if ((evsel->attr.read_format & PERF_FORMAT_ID) && + evsel->sample_id == NULL && + perf_evsel__alloc_id(evsel, perf_cpu_map__nr(cpus), threads->nr) < 0) + return -ENOMEM; + } + + evlist->mmap_len = (pages + 1) * page_size; + mp.mask = evlist->mmap_len - page_size - 1; + + if (perf_cpu_map__empty(cpus)) + return mmap_per_thread(evlist, &mp); + + return mmap_per_cpu(evlist, &mp); +} + +void perf_evlist__munmap(struct perf_evlist *evlist) +{ + int i; + + if (evlist->mmap) { + for (i = 0; i < evlist->nr_mmaps; i++) + perf_mmap__munmap(&evlist->mmap[i]); + } + + if (evlist->mmap_ovw) { + for (i = 0; i < evlist->nr_mmaps; i++) + perf_mmap__munmap(&evlist->mmap_ovw[i]); + } + + zfree(&evlist->mmap); + zfree(&evlist->mmap_ovw); +} diff --git a/tools/perf/lib/include/internal/evlist.h b/tools/perf/lib/include/internal/evlist.h index 9f440ab12b76..4438a19ceba3 100644 --- a/tools/perf/lib/include/internal/evlist.h +++ b/tools/perf/lib/include/internal/evlist.h @@ -22,6 +22,8 @@ struct perf_evlist { size_t mmap_len; struct fdarray pollfd; struct hlist_head heads[PERF_EVLIST__HLIST_SIZE]; + struct perf_mmap *mmap; + struct perf_mmap *mmap_ovw; }; int perf_evlist__alloc_pollfd(struct perf_evlist *evlist); diff --git a/tools/perf/lib/include/perf/evlist.h b/tools/perf/lib/include/perf/evlist.h index 8a2ce0757ab2..28b6a12a8a2b 100644 --- a/tools/perf/lib/include/perf/evlist.h +++ b/tools/perf/lib/include/perf/evlist.h @@ -33,4 +33,7 @@ LIBPERF_API void perf_evlist__set_maps(struct perf_evlist *evlist, struct perf_thread_map *threads); LIBPERF_API int perf_evlist__poll(struct perf_evlist *evlist, int timeout); +LIBPERF_API int perf_evlist__mmap(struct perf_evlist *evlist, int pages); +LIBPERF_API void perf_evlist__munmap(struct perf_evlist *evlist); + #endif /* __LIBPERF_EVLIST_H */ diff --git a/tools/perf/lib/libperf.map b/tools/perf/lib/libperf.map index 8bb0d73e0c6c..5a18fd1aacf2 100644 --- a/tools/perf/lib/libperf.map +++ b/tools/perf/lib/libperf.map @@ -40,6 +40,8 @@ LIBPERF_0.0.1 { perf_evlist__next; perf_evlist__set_maps; perf_evlist__poll; + perf_evlist__mmap; + perf_evlist__munmap; perf_mmap__consume; perf_mmap__read_init; perf_mmap__read_done; -- GitLab