From 70082dd92c4b288bd723a77897e2b555f0e63113 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 12 Jan 2011 17:03:24 -0200 Subject: [PATCH] perf evsel: Introduce mmap support Out of the code in 'perf top'. Record is next in line. Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Tom Zanussi LKML-Reference: Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-top.c | 71 ++++-------------------------------------------- tools/perf/perf.h | 14 ++++++++++ tools/perf/util/evlist.c | 8 ++++++ tools/perf/util/evlist.h | 1 + tools/perf/util/evsel.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/evsel.h | 8 ++++++ 6 files changed, 107 insertions(+), 66 deletions(-) diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 15d89be..7d723ad 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -1095,43 +1095,12 @@ static void event__process_sample(const event_t *self, } } -struct mmap_data { - void *base; - int mask; - unsigned int prev; -}; - -static int perf_evsel__alloc_mmap_per_thread(struct perf_evsel *evsel, - int ncpus, int nthreads) -{ - evsel->priv = xyarray__new(ncpus, nthreads, sizeof(struct mmap_data)); - return evsel->priv != NULL ? 0 : -ENOMEM; -} - -static void perf_evsel__free_mmap(struct perf_evsel *evsel) -{ - xyarray__delete(evsel->priv); - evsel->priv = NULL; -} - -static unsigned int mmap_read_head(struct mmap_data *md) -{ - struct perf_event_mmap_page *pc = md->base; - int head; - - head = pc->data_head; - rmb(); - - return head; -} - static void perf_session__mmap_read_counter(struct perf_session *self, struct perf_evsel *evsel, int cpu, int thread_idx) { - struct xyarray *mmap_array = evsel->priv; - struct mmap_data *md = xyarray__entry(mmap_array, cpu, thread_idx); - unsigned int head = mmap_read_head(md); + struct perf_mmap *md = xyarray__entry(evsel->mmap, cpu, thread_idx); + unsigned int head = perf_mmap__read_head(md); unsigned int old = md->prev; unsigned char *data = md->base + page_size; struct sample_data sample; @@ -1210,35 +1179,9 @@ static void perf_session__mmap_read(struct perf_session *self) } } -static void start_counter(int i, struct perf_evlist *evlist, - struct perf_evsel *evsel) -{ - struct xyarray *mmap_array = evsel->priv; - struct mmap_data *mm; - int thread_index; - - for (thread_index = 0; thread_index < threads->nr; thread_index++) { - assert(FD(evsel, i, thread_index) >= 0); - fcntl(FD(evsel, i, thread_index), F_SETFL, O_NONBLOCK); - - evlist->pollfd[evlist->nr_fds].fd = FD(evsel, i, thread_index); - evlist->pollfd[evlist->nr_fds].events = POLLIN; - evlist->nr_fds++; - - mm = xyarray__entry(mmap_array, i, thread_index); - mm->prev = 0; - mm->mask = mmap_pages*page_size - 1; - mm->base = mmap(NULL, (mmap_pages+1)*page_size, - PROT_READ, MAP_SHARED, FD(evsel, i, thread_index), 0); - if (mm->base == MAP_FAILED) - die("failed to mmap with %d (%s)\n", errno, strerror(errno)); - } -} - static void start_counters(struct perf_evlist *evlist) { struct perf_evsel *counter; - int i; list_for_each_entry(counter, &evlist->entries, node) { struct perf_event_attr *attr = &counter->attr; @@ -1282,11 +1225,9 @@ try_again: die("No CONFIG_PERF_EVENTS=y kernel support configured?\n"); exit(-1); } - } - for (i = 0; i < cpus->nr; i++) { - list_for_each_entry(counter, &evlist->entries, node) - start_counter(i, evsel_list, counter); + if (perf_evsel__mmap(counter, cpus, threads, mmap_pages, evlist) < 0) + die("failed to mmap with %d (%s)\n", errno, strerror(errno)); } } @@ -1453,7 +1394,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __used) usage_with_options(top_usage, options); list_for_each_entry(pos, &evsel_list->entries, node) { - if (perf_evsel__alloc_mmap_per_thread(pos, cpus->nr, threads->nr) < 0 || + if (perf_evsel__alloc_mmap(pos, cpus->nr, threads->nr) < 0 || perf_evsel__alloc_fd(pos, cpus->nr, threads->nr) < 0) goto out_free_fd; /* @@ -1485,8 +1426,6 @@ int cmd_top(int argc, const char **argv, const char *prefix __used) status = __cmd_top(); out_free_fd: - list_for_each_entry(pos, &evsel_list->entries, node) - perf_evsel__free_mmap(pos); perf_evlist__delete(evsel_list); return status; diff --git a/tools/perf/perf.h b/tools/perf/perf.h index 95aaf56..5fb5e1f 100644 --- a/tools/perf/perf.h +++ b/tools/perf/perf.h @@ -94,6 +94,20 @@ void get_term_dimensions(struct winsize *ws); #include "util/types.h" #include +struct perf_mmap { + void *base; + int mask; + unsigned int prev; +}; + +static inline unsigned int perf_mmap__read_head(struct perf_mmap *mm) +{ + struct perf_event_mmap_page *pc = mm->base; + int head = pc->data_head; + rmb(); + return head; +} + /* * prctl(PR_TASK_PERF_EVENTS_DISABLE) will (cheaply) disable all * counters in the current task. diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 2abf949..6d41292 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -60,3 +60,11 @@ int perf_evlist__alloc_pollfd(struct perf_evlist *evlist, int ncpus, int nthread evlist->pollfd = malloc(sizeof(struct pollfd) * nfds); return evlist->pollfd != NULL ? 0 : -ENOMEM; } + +void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd) +{ + fcntl(fd, F_SETFL, O_NONBLOCK); + evlist->pollfd[evlist->nr_fds].fd = fd; + evlist->pollfd[evlist->nr_fds].events = POLLIN; + evlist->nr_fds++; +} diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index a7d7e12..16bbfcb 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -21,5 +21,6 @@ void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry); int perf_evlist__add_default(struct perf_evlist *evlist); int perf_evlist__alloc_pollfd(struct perf_evlist *evlist, int ncpus, int nthreads); +void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd); #endif /* __PERF_EVLIST_H */ diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 82a0053..f500695 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -1,9 +1,13 @@ #include "evsel.h" +#include "evlist.h" #include "../perf.h" #include "util.h" #include "cpumap.h" #include "thread.h" +#include +#include + #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y)) struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr, int idx) @@ -49,10 +53,32 @@ void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads) } } +void perf_evsel__munmap(struct perf_evsel *evsel, int ncpus, int nthreads) +{ + struct perf_mmap *mm; + int cpu, thread; + + for (cpu = 0; cpu < ncpus; cpu++) + for (thread = 0; thread < nthreads; ++thread) { + mm = xyarray__entry(evsel->mmap, cpu, thread); + if (mm->base != NULL) { + munmap(mm->base, evsel->mmap_len); + mm->base = NULL; + } + } +} + +int perf_evsel__alloc_mmap(struct perf_evsel *evsel, int ncpus, int nthreads) +{ + evsel->mmap = xyarray__new(ncpus, nthreads, sizeof(struct perf_mmap)); + return evsel->mmap != NULL ? 0 : -ENOMEM; +} + void perf_evsel__delete(struct perf_evsel *evsel) { assert(list_empty(&evsel->node)); xyarray__delete(evsel->fd); + xyarray__delete(evsel->mmap); free(evsel); } @@ -208,3 +234,48 @@ int perf_evsel__open_per_thread(struct perf_evsel *evsel, { return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group, inherit); } + +int perf_evsel__mmap(struct perf_evsel *evsel, struct cpu_map *cpus, + struct thread_map *threads, int pages, + struct perf_evlist *evlist) +{ + unsigned int page_size = sysconf(_SC_PAGE_SIZE); + int mask = pages * page_size - 1, cpu; + struct perf_mmap *mm; + int thread; + + if (evsel->mmap == NULL && + perf_evsel__alloc_mmap(evsel, cpus->nr, threads->nr) < 0) + return -ENOMEM; + + evsel->mmap_len = (pages + 1) * page_size; + + for (cpu = 0; cpu < cpus->nr; cpu++) { + for (thread = 0; thread < threads->nr; thread++) { + mm = xyarray__entry(evsel->mmap, cpu, thread); + mm->prev = 0; + mm->mask = mask; + mm->base = mmap(NULL, evsel->mmap_len, PROT_READ, + MAP_SHARED, FD(evsel, cpu, thread), 0); + if (mm->base == MAP_FAILED) + goto out_unmap; + + if (evlist != NULL) + perf_evlist__add_pollfd(evlist, FD(evsel, cpu, thread)); + } + } + + return 0; + +out_unmap: + do { + while (--thread >= 0) { + mm = xyarray__entry(evsel->mmap, cpu, thread); + munmap(mm->base, evsel->mmap_len); + mm->base = NULL; + } + thread = threads->nr; + } while (--cpu >= 0); + + return -1; +} diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index 1594696..c8fbef2 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -29,19 +29,23 @@ struct perf_evsel { struct perf_event_attr attr; char *filter; struct xyarray *fd; + struct xyarray *mmap; struct perf_counts *counts; + size_t mmap_len; int idx; void *priv; }; struct cpu_map; struct thread_map; +struct perf_evlist; struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr, int idx); void perf_evsel__delete(struct perf_evsel *evsel); int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads); int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus); +int perf_evsel__alloc_mmap(struct perf_evsel *evsel, int ncpus, int nthreads); void perf_evsel__free_fd(struct perf_evsel *evsel); void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads); @@ -51,6 +55,10 @@ int perf_evsel__open_per_thread(struct perf_evsel *evsel, struct thread_map *threads, bool group, bool inherit); int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus, struct thread_map *threads, bool group, bool inherit); +int perf_evsel__mmap(struct perf_evsel *evsel, struct cpu_map *cpus, + struct thread_map *threads, int pages, + struct perf_evlist *evlist); +void perf_evsel__munmap(struct perf_evsel *evsel, int ncpus, int nthreads); #define perf_evsel__match(evsel, t, c) \ (evsel->attr.type == PERF_TYPE_##t && \ -- 2.7.4