diff options
Diffstat (limited to 'tools/perf/util')
-rw-r--r-- | tools/perf/util/Build | 1 | ||||
-rw-r--r-- | tools/perf/util/bpf_ftrace.c | 112 | ||||
-rw-r--r-- | tools/perf/util/bpf_skel/func_latency.bpf.c | 93 | ||||
-rw-r--r-- | tools/perf/util/ftrace.h | 81 |
4 files changed, 287 insertions, 0 deletions
diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 2e5bfbb69960..294b12430d73 100644 --- a/tools/perf/util/Build +++ b/tools/perf/util/Build @@ -144,6 +144,7 @@ perf-$(CONFIG_LIBBPF) += bpf-loader.o perf-$(CONFIG_LIBBPF) += bpf_map.o perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter.o perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter_cgroup.o +perf-$(CONFIG_PERF_BPF_SKEL) += bpf_ftrace.o perf-$(CONFIG_BPF_PROLOGUE) += bpf-prologue.o perf-$(CONFIG_LIBELF) += symbol-elf.o perf-$(CONFIG_LIBELF) += probe-file.o diff --git a/tools/perf/util/bpf_ftrace.c b/tools/perf/util/bpf_ftrace.c new file mode 100644 index 000000000000..ec4e2f5a2fc4 --- /dev/null +++ b/tools/perf/util/bpf_ftrace.c @@ -0,0 +1,112 @@ +#include <stdio.h> +#include <fcntl.h> +#include <stdint.h> +#include <stdlib.h> + +#include <linux/err.h> + +#include "util/ftrace.h" +#include "util/cpumap.h" +#include "util/debug.h" +#include "util/bpf_counter.h" + +#include "util/bpf_skel/func_latency.skel.h" + +static struct func_latency_bpf *skel; + +int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace) +{ + int err; + struct filter_entry *func; + + if (!list_is_singular(&ftrace->filters)) { + pr_err("ERROR: %s target function(s).\n", + list_empty(&ftrace->filters) ? "No" : "Too many"); + return -1; + } + + func = list_first_entry(&ftrace->filters, struct filter_entry, list); + + skel = func_latency_bpf__open(); + if (!skel) { + pr_err("Failed to open func latency skeleton\n"); + return -1; + } + + set_max_rlimit(); + + err = func_latency_bpf__load(skel); + if (err) { + pr_err("Failed to load func latency skeleton\n"); + goto out; + } + + skel->links.func_begin = bpf_program__attach_kprobe(skel->progs.func_begin, + false, func->name); + if (IS_ERR(skel->links.func_begin)) { + pr_err("Failed to attach fentry program\n"); + err = PTR_ERR(skel->links.func_begin); + goto out; + } + + skel->links.func_end = bpf_program__attach_kprobe(skel->progs.func_end, + true, func->name); + if (IS_ERR(skel->links.func_end)) { + pr_err("Failed to attach fexit program\n"); + err = PTR_ERR(skel->links.func_end); + goto out; + } + + /* XXX: we don't actually use this fd - just for poll() */ + return open("/dev/null", O_RDONLY); + +out: + return err; +} + +int perf_ftrace__latency_start_bpf(struct perf_ftrace *ftrace __maybe_unused) +{ + skel->bss->enabled = 1; + return 0; +} + +int perf_ftrace__latency_stop_bpf(struct perf_ftrace *ftrace __maybe_unused) +{ + skel->bss->enabled = 0; + return 0; +} + +int perf_ftrace__latency_read_bpf(struct perf_ftrace *ftrace __maybe_unused, + int buckets[]) +{ + int i, fd, err; + u32 idx; + u64 *hist; + int ncpus = cpu__max_cpu(); + + fd = bpf_map__fd(skel->maps.latency); + + hist = calloc(ncpus, sizeof(*hist)); + if (hist == NULL) + return -ENOMEM; + + for (idx = 0; idx < NUM_BUCKET; idx++) { + err = bpf_map_lookup_elem(fd, &idx, hist); + if (err) { + buckets[idx] = 0; + continue; + } + + for (i = 0; i < ncpus; i++) + buckets[idx] += hist[i]; + } + + free(hist); + return 0; +} + +int perf_ftrace__latency_cleanup_bpf(struct perf_ftrace *ftrace __maybe_unused) +{ + func_latency_bpf__destroy(skel); + return 0; +} diff --git a/tools/perf/util/bpf_skel/func_latency.bpf.c b/tools/perf/util/bpf_skel/func_latency.bpf.c new file mode 100644 index 000000000000..ccd96b09fc42 --- /dev/null +++ b/tools/perf/util/bpf_skel/func_latency.bpf.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +// Copyright (c) 2021 Google +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +// This should be in sync with "util/ftrace.h" +#define NUM_BUCKET 22 + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(key_size, sizeof(__u64)); + __uint(value_size, sizeof(__u64)); + __uint(max_entries, 10000); +} functime SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(__u8)); + __uint(max_entries, 1); +} cpu_filter SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(__u8)); + __uint(max_entries, 1); +} task_filter SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(__u64)); + __uint(max_entries, NUM_BUCKET); +} latency SEC(".maps"); + + +int enabled = 0; + +SEC("kprobe/func") +int BPF_PROG(func_begin) +{ + __u64 key, now; + + if (!enabled) + return 0; + + key = bpf_get_current_pid_tgid(); + now = bpf_ktime_get_ns(); + + // overwrite timestamp for nested functions + bpf_map_update_elem(&functime, &key, &now, BPF_ANY); + return 0; +} + +SEC("kretprobe/func") +int BPF_PROG(func_end) +{ + __u64 tid; + __u64 *start; + + if (!enabled) + return 0; + + tid = bpf_get_current_pid_tgid(); + + start = bpf_map_lookup_elem(&functime, &tid); + if (start) { + __s64 delta = bpf_ktime_get_ns() - *start; + __u32 key; + __u64 *hist; + + bpf_map_delete_elem(&functime, &tid); + + if (delta < 0) + return 0; + + // calculate index using delta in usec + for (key = 0; key < (NUM_BUCKET - 1); key++) { + if (delta < ((1000UL) << key)) + break; + } + + hist = bpf_map_lookup_elem(&latency, &key); + if (!hist) + return 0; + + *hist += 1; + } + + return 0; +} diff --git a/tools/perf/util/ftrace.h b/tools/perf/util/ftrace.h new file mode 100644 index 000000000000..887f68a185f7 --- /dev/null +++ b/tools/perf/util/ftrace.h @@ -0,0 +1,81 @@ +#ifndef __PERF_FTRACE_H__ +#define __PERF_FTRACE_H__ + +#include <linux/list.h> + +#include "target.h" + +struct evlist; + +struct perf_ftrace { + struct evlist *evlist; + struct target target; + const char *tracer; + struct list_head filters; + struct list_head notrace; + struct list_head graph_funcs; + struct list_head nograph_funcs; + unsigned long percpu_buffer_size; + bool inherit; + int graph_depth; + int func_stack_trace; + int func_irq_info; + int graph_nosleep_time; + int graph_noirqs; + int graph_verbose; + int graph_thresh; + unsigned int initial_delay; +}; + +struct filter_entry { + struct list_head list; + char name[]; +}; + +#define NUM_BUCKET 22 /* 20 + 2 (for outliers in both direction) */ + +#ifdef HAVE_BPF_SKEL + +int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace); +int perf_ftrace__latency_start_bpf(struct perf_ftrace *ftrace); +int perf_ftrace__latency_stop_bpf(struct perf_ftrace *ftrace); +int perf_ftrace__latency_read_bpf(struct perf_ftrace *ftrace, + int buckets[]); +int perf_ftrace__latency_cleanup_bpf(struct perf_ftrace *ftrace); + +#else /* !HAVE_BPF_SKEL */ + +static inline int +perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace __maybe_unused) +{ + return -1; +} + +static inline int +perf_ftrace__latency_start_bpf(struct perf_ftrace *ftrace __maybe_unused) +{ + return -1; +} + +static inline int +perf_ftrace__latency_stop_bpf(struct perf_ftrace *ftrace __maybe_unused) +{ + return -1; +} + +static inline int +perf_ftrace__latency_read_bpf(struct perf_ftrace *ftrace __maybe_unused, + int buckets[] __maybe_unused) +{ + return -1; +} + +static inline int +perf_ftrace__latency_cleanup_bpf(struct perf_ftrace *ftrace __maybe_unused) +{ + return -1; +} + +#endif /* HAVE_BPF_SKEL */ + +#endif /* __PERF_FTRACE_H__ */ |