Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758398AbcDHPLO (ORCPT ); Fri, 8 Apr 2016 11:11:14 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:47154 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752821AbcDHPLN (ORCPT ); Fri, 8 Apr 2016 11:11:13 -0400 From: Wang Nan To: CC: , , , , Wang Nan , "Arnaldo Carvalho de Melo" , Jiri Olsa Subject: [PATCH 4/4] perf bpf: Automatically create bpf-output event __bpf_stdout__ Date: Fri, 8 Apr 2016 15:07:25 +0000 Message-ID: <1460128045-97310-5-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1460128045-97310-1-git-send-email-wangnan0@huawei.com> References: <1460128045-97310-1-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 X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020201.5707C93B.0085,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 9bed3d5654bbc52bd39c461b6763eecc Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4842 Lines: 151 This patch allows ignoring bpf-output event setting in cmdline. By adding a map named '__bpf_stdout__', perf automatically creates an event for it. For example: # perf record -e ./test_bpf_trace.c usleep 100000 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.012 MB perf.data (2 samples) ] # ~/perf script usleep 4639 [000] 261895.307826: 0 __bpf_stdout__: ffffffff810eb9a1 ... BPF output: 0000: 52 61 69 73 65 20 61 20 Raise a 0008: 42 50 46 20 65 76 65 6e BPF even 0010: 74 21 00 00 t!.. BPF string: "Raise a BPF event!" usleep 4639 [000] 261895.407883: 0 __bpf_stdout__: ffffffff8105d609 ... BPF output: 0000: 52 61 69 73 65 20 61 20 Raise a 0008: 42 50 46 20 65 76 65 6e BPF even 0010: 74 21 00 00 t!.. BPF string: "Raise a BPF event!" perf record -e ./test_bpf_trace.c usleep 100000 equals to perf record -e bpf-output/no-inherit=1,name=__bpf_stdout__/ \ -e ./test_bpf_trace.c/map:__bpf_stdout__.event=__bpf_stdout__/ \ usleep 100000 Where test_bpf_trace.c is: /************************ BEGIN **************************/ #include struct bpf_map_def { unsigned int type; unsigned int key_size; unsigned int value_size; unsigned int max_entries; }; #define SEC(NAME) __attribute__((section(NAME), used)) static u64 (*ktime_get_ns)(void) = (void *)BPF_FUNC_ktime_get_ns; static int (*trace_printk)(const char *fmt, int fmt_size, ...) = (void *)BPF_FUNC_trace_printk; static int (*get_smp_processor_id)(void) = (void *)BPF_FUNC_get_smp_processor_id; static int (*perf_event_output)(void *, struct bpf_map_def *, int, void *, unsigned long) = (void *)BPF_FUNC_perf_event_output; struct bpf_map_def SEC("maps") __bpf_stdout__ = { .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, .key_size = sizeof(int), .value_size = sizeof(u32), .max_entries = __NR_CPUS__, }; static inline int __attribute__((always_inline)) func(void *ctx, int type) { char output_str[] = "Raise a BPF event!"; char err_str[] = "BAD %d\n"; int err; err = perf_event_output(ctx, &channel, get_smp_processor_id(), &output_str, sizeof(output_str)); if (err) trace_printk(err_str, sizeof(err_str), err); return 1; } SEC("func_begin=sys_nanosleep") int func_begin(void *ctx) {return func(ctx, 1);} SEC("func_end=sys_nanosleep%return") int func_end(void *ctx) { return func(ctx, 2);} char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; /************************* END ***************************/ Signed-off-by: Wang Nan Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Li Zefan Cc: pi3orama@163.com --- tools/perf/util/bpf-loader.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c index a0d2802..1bd7d5b 100644 --- a/tools/perf/util/bpf-loader.c +++ b/tools/perf/util/bpf-loader.c @@ -1483,6 +1483,7 @@ int bpf__setup_stdout(struct perf_evlist *evlist __maybe_unused) { struct bpf_map_priv *tmpl_priv = NULL; struct bpf_object *obj, *tmp; + struct perf_evsel *evsel = NULL; struct bpf_map *map; int err; bool need_init = false; @@ -1507,8 +1508,16 @@ int bpf__setup_stdout(struct perf_evlist *evlist __maybe_unused) if (!need_init) return 0; - if (!tmpl_priv) - return 0; + if (!tmpl_priv) { + err = parse_events(evlist, "bpf-output/no-inherit=1,name=__bpf_stdout__/", + NULL); + if (err) { + pr_debug("ERROR: failed to create bpf-output event\n"); + return -err; + } + + evsel = perf_evlist__last(evlist); + } bpf__for_each_stdout_map(map, obj, tmp) { struct bpf_map_priv *priv; @@ -1519,14 +1528,24 @@ int bpf__setup_stdout(struct perf_evlist *evlist __maybe_unused) if (priv) continue; - priv = bpf_map_priv__clone(tmpl_priv); - if (!priv) - return -ENOMEM; + if (tmpl_priv) { + priv = bpf_map_priv__clone(tmpl_priv); + if (!priv) + return -ENOMEM; - err = bpf_map__set_private(map, priv, bpf_map_priv__clear); - if (err) { - bpf_map_priv__clear(map, priv); - return err; + err = bpf_map__set_private(map, priv, bpf_map_priv__clear); + if (err) { + bpf_map_priv__clear(map, priv); + return err; + } + } else if (evsel) { + struct bpf_map_op *op; + + op = bpf_map__add_newop(map, NULL); + if (IS_ERR(op)) + return PTR_ERR(op); + op->op_type = BPF_MAP_OP_SET_EVSEL; + op->v.evsel = evsel; } } -- 1.8.3.4