From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753727AbbJNMs4 (ORCPT ); Wed, 14 Oct 2015 08:48:56 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:50259 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753574AbbJNMmx (ORCPT ); Wed, 14 Oct 2015 08:42:53 -0400 From: Wang Nan To: , , CC: , , , , , , , , , , , , Wang Nan , Arnaldo Carvalho de Melo Subject: [PATCH 06/31] perf tools: Collect perf_evsel in BPF object files Date: Wed, 14 Oct 2015 12:41:17 +0000 Message-ID: <1444826502-49291-7-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1444826502-49291-1-git-send-email-wangnan0@huawei.com> References: <1444826502-49291-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch collects 'struct perf_evsel' for every probing points in BPF object file(s) and fill 'struct evlist'. The previous introduced dummy event now removed. After this patch, following command: # perf record --event filter.o ls Can trace on each probing points defined in filter.o. The core of this patch is bpf__foreach_tev(), which calls a callback function for each 'struct probe_trace_event' events for a bpf program with their file descriptors. Callback function add_bpf_event() creates evsels by calling parse_events_add_tracepoint(). Since bpf-loader.c will not be built if libbpf is turned off, an empty bpf__foreach_tev() is defined in bpf-loader.h to avoid compiling error. Signed-off-by: Wang Nan Cc: Alexei Starovoitov Cc: Brendan Gregg Cc: Daniel Borkmann Cc: David Ahern Cc: He Kuang Cc: Jiri Olsa Cc: Kaixu Xia Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Cc: Arnaldo Carvalho de Melo Link: http://lkml.kernel.org/n/ebpf-6yw9eg0ej3l4jnqhinngkw86@git.kernel.org --- tools/perf/util/bpf-loader.c | 40 ++++++++++++++++++++++++++++++++ tools/perf/util/bpf-loader.h | 14 ++++++++++++ tools/perf/util/parse-events.c | 52 ++++++++++++++++++++++++++++++++++++------ 3 files changed, 99 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c index 7279558..aa784a4 100644 --- a/tools/perf/util/bpf-loader.c +++ b/tools/perf/util/bpf-loader.c @@ -255,6 +255,46 @@ int bpf__load(struct bpf_object *obj) return 0; } +int bpf__foreach_tev(struct bpf_object *obj, + bpf_prog_iter_callback_t func, + void *arg) +{ + struct bpf_program *prog; + int err; + + bpf_object__for_each_program(prog, obj) { + struct probe_trace_event *tev; + struct perf_probe_event *pev; + struct bpf_prog_priv *priv; + int i, fd; + + err = bpf_program__get_private(prog, + (void **)&priv); + if (err || !priv) { + pr_debug("bpf: failed to get private field\n"); + return -EINVAL; + } + + pev = &priv->pev; + for (i = 0; i < pev->ntevs; i++) { + tev = &pev->tevs[i]; + + fd = bpf_program__fd(prog); + if (fd < 0) { + pr_debug("bpf: failed to get file descriptor\n"); + return fd; + } + + err = (*func)(tev, fd, arg); + if (err) { + pr_debug("bpf: call back failed, stop iterate\n"); + return err; + } + } + } + return 0; +} + #define bpf__strerror_head(err, buf, size) \ char sbuf[STRERR_BUFSIZE], *emsg;\ if (!size)\ diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h index b091ceb..a8f25ee 100644 --- a/tools/perf/util/bpf-loader.h +++ b/tools/perf/util/bpf-loader.h @@ -8,11 +8,15 @@ #include #include #include +#include "probe-event.h" #include "debug.h" struct bpf_object; #define PERF_BPF_PROBE_GROUP "perf_bpf_probe" +typedef int (*bpf_prog_iter_callback_t)(struct probe_trace_event *tev, + int fd, void *arg); + #ifdef HAVE_LIBBPF_SUPPORT struct bpf_object *bpf__prepare_load(const char *filename); @@ -26,6 +30,8 @@ int bpf__strerror_probe(struct bpf_object *obj, int err, int bpf__load(struct bpf_object *obj); int bpf__strerror_load(struct bpf_object *obj, int err, char *buf, size_t size); +int bpf__foreach_tev(struct bpf_object *obj, + bpf_prog_iter_callback_t func, void *arg); #else static inline struct bpf_object * bpf__prepare_load(const char *filename __maybe_unused) @@ -41,6 +47,14 @@ static inline int bpf__unprobe(struct bpf_object *obj __maybe_unused) { return 0 static inline int bpf__load(struct bpf_object *obj __maybe_unused) { return 0; } static inline int +bpf__foreach_tev(struct bpf_object *obj __maybe_unused, + bpf_prog_iter_callback_t func __maybe_unused, + void *arg __maybe_unused) +{ + return 0; +} + +static inline int __bpf_strerror(char *buf, size_t size) { if (!size) diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index 5b17b88..61c7a47 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -530,12 +530,49 @@ static int add_tracepoint_multi_sys(struct list_head *list, int *idx, return ret; } +struct __add_bpf_event_param { + struct parse_events_evlist *data; + struct list_head *list; +}; + +static int add_bpf_event(struct probe_trace_event *tev, int fd, + void *_param) +{ + LIST_HEAD(new_evsels); + struct __add_bpf_event_param *param = _param; + struct parse_events_evlist *evlist = param->data; + struct list_head *list = param->list; + int err; + + pr_debug("add bpf event %s:%s and attach bpf program %d\n", + tev->group, tev->event, fd); + + err = parse_events_add_tracepoint(&new_evsels, &evlist->idx, tev->group, + tev->event, evlist->error, NULL); + if (err) { + struct perf_evsel *evsel, *tmp; + + pr_debug("Failed to add BPF event %s:%s\n", + tev->group, tev->event); + list_for_each_entry_safe(evsel, tmp, &new_evsels, node) { + list_del(&evsel->node); + perf_evsel__delete(evsel); + } + return err; + } + pr_debug("adding %s:%s\n", tev->group, tev->event); + + list_splice(&new_evsels, list); + return 0; +} + int parse_events_load_bpf_obj(struct parse_events_evlist *data, struct list_head *list, struct bpf_object *obj) { int err; char errbuf[BUFSIZ]; + struct __add_bpf_event_param param = {data, list}; static bool registered_unprobe_atexit = false; if (IS_ERR(obj) || !obj) { @@ -567,13 +604,14 @@ int parse_events_load_bpf_obj(struct parse_events_evlist *data, goto errout; } - /* - * Temporary add a dummy event here so we can check whether - * basic bpf loader works. Following patches will replace - * dummy event by useful evsels. - */ - return parse_events_add_numeric(data, list, PERF_TYPE_SOFTWARE, - PERF_COUNT_SW_DUMMY, NULL); + err = bpf__foreach_tev(obj, add_bpf_event, ¶m); + if (err) { + snprintf(errbuf, sizeof(errbuf), + "Attach events in BPF object failed"); + goto errout; + } + + return 0; errout: data->error->help = strdup("(add -v to see detail)"); data->error->str = strdup(errbuf); -- 1.8.3.4