Re: [PATCH 03/31] perf tools: Enable passing bpf object file to --event

From: Arnaldo Carvalho de Melo
Date: Tue Oct 20 2015 - 11:13:10 EST

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Em Wed, Oct 14, 2015 at 12:41:14PM +0000, Wang Nan escreveu:
> By introducing new rules in tools/perf/util/parse-events.[ly], this
> patch enables 'perf record --event bpf_file.o' to select events by an
> eBPF object file. It calls parse_events_load_bpf() to load that file,
> which uses bpf__prepare_load() and finally calls bpf_object__open() for
> the object files.
>
> After applying this patch, commands like:
>
> # perf record --event foo.o sleep
>
> become possible.

So, trying the above command I get almost perfect output:

[root@felicio ~]# perf record --event foo.o sleep
libbpf: failed to open foo.o: No such file or directory
event syntax error: 'foo.o'
\___ BPF object file 'foo.o' is invalid

(add -v to see detail)
Run 'perf list' for a list of valid events

Usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]

-e, --event <event> event selector. use 'perf list' to list available events
[root@felicio ~]#

Good thing would be to not have any message from libbpf and the right error
message from the parser, i.e. the first three lines become these two:

event syntax error: 'foo.o'
\___ BPF object file 'foo.o' not found.o

But that can be fixed up in an upcoming patch, so I am applying this one now in
my new attempt at processing this patchkit.

- Arnaldo

> However, at this point it is unable to link any useful things onto the
> evsel list because the creating of probe points and BPF program
> attaching have not been implemented. Before real events are possible to
> be extracted, to avoid perf report error because of empty evsel list,
> this patch link a dummy evsel. The dummy event related code will be
> removed when probing and extracting code is ready.
>
> Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
> Cc: Alexei Starovoitov <ast@xxxxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Cc: Brendan Gregg <brendan.d.gregg@xxxxxxxxx>
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: David Ahern <dsahern@xxxxxxxxx>
> Cc: He Kuang <hekuang@xxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Kaixu Xia <xiakaixu@xxxxxxxxxx>
> Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Cc: Zefan Li <lizefan@xxxxxxxxxx>
> Cc: pi3orama@xxxxxxx
> Link: http://lkml.kernel.org/n/ebpf-6yw9eg0ej3l4jnqhinngkw86@xxxxxxxxxxxxxx
> ---
> tools/perf/perf.c | 2 ++
> tools/perf/util/Build | 1 +
> tools/perf/util/parse-events.c | 57 ++++++++++++++++++++++++++++++++++++++++++
> tools/perf/util/parse-events.h | 8 ++++++
> tools/perf/util/parse-events.l | 3 +++
> tools/perf/util/parse-events.y | 18 ++++++++++++-
> 6 files changed, 88 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/perf.c b/tools/perf/perf.c
> index 5437134..3d4c7c0 100644
> --- a/tools/perf/perf.c
> +++ b/tools/perf/perf.c
> @@ -15,6 +15,7 @@
> #include "util/run-command.h"
> #include "util/parse-events.h"
> #include "util/parse-options.h"
> +#include "util/bpf-loader.h"
> #include "util/debug.h"
> #include <api/fs/tracing_path.h>
> #include <pthread.h>
> @@ -385,6 +386,7 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
> status = p->fn(argc, argv, prefix);
> exit_browser(status);
> perf_env__exit(&perf_env);
> + bpf__clear();
>
> if (status)
> return status & 0xff;
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 9217119..591b3fe 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -87,6 +87,7 @@ libperf-$(CONFIG_AUXTRACE) += intel-bts.o
> libperf-y += parse-branch-options.o
> libperf-y += parse-regs-options.o
>
> +libperf-$(CONFIG_LIBBPF) += bpf-loader.o
> libperf-$(CONFIG_LIBELF) += symbol-elf.o
> libperf-$(CONFIG_LIBELF) += probe-file.o
> libperf-$(CONFIG_LIBELF) += probe-event.o
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 991bbd4..a02abd3 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -11,6 +11,7 @@
> #include "symbol.h"
> #include "cache.h"
> #include "header.h"
> +#include "bpf-loader.h"
> #include "debug.h"
> #include <api/fs/tracing_path.h>
> #include "parse-events-bison.h"
> @@ -529,6 +530,62 @@ static int add_tracepoint_multi_sys(struct list_head *list, int *idx,
> return ret;
> }
>
> +int parse_events_load_bpf_obj(struct parse_events_evlist *data,
> + struct list_head *list,
> + struct bpf_object *obj)
> +{
> + int err;
> + char errbuf[BUFSIZ];
> +
> + if (IS_ERR(obj) || !obj) {
> + snprintf(errbuf, sizeof(errbuf),
> + "Internal error: load bpf obj with NULL");
> + err = -EINVAL;
> + 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);
> +errout:
> + data->error->help = strdup("(add -v to see detail)");
> + data->error->str = strdup(errbuf);
> + return err;
> +}
> +
> +int parse_events_load_bpf(struct parse_events_evlist *data,
> + struct list_head *list,
> + char *bpf_file_name)
> +{
> + struct bpf_object *obj;
> +
> + obj = bpf__prepare_load(bpf_file_name);
> + if (IS_ERR(obj) || !obj) {
> + char errbuf[BUFSIZ];
> + int err;
> +
> + err = obj ? PTR_ERR(obj) : -EINVAL;
> +
> + if (err == -ENOTSUP)
> + snprintf(errbuf, sizeof(errbuf),
> + "BPF support is not compiled");
> + else
> + snprintf(errbuf, sizeof(errbuf),
> + "BPF object file '%s' is invalid",
> + bpf_file_name);
> +
> + data->error->help = strdup("(add -v to see detail)");
> + data->error->str = strdup(errbuf);
> + return err;
> + }
> +
> + return parse_events_load_bpf_obj(data, list, obj);
> +}
> +
> static int
> parse_breakpoint_type(const char *type, struct perf_event_attr *attr)
> {
> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> index f13d3cc..fbb16c7 100644
> --- a/tools/perf/util/parse-events.h
> +++ b/tools/perf/util/parse-events.h
> @@ -121,6 +121,14 @@ int parse_events_add_tracepoint(struct list_head *list, int *idx,
> char *sys, char *event,
> struct parse_events_error *error,
> struct list_head *head_config);
> +int parse_events_load_bpf(struct parse_events_evlist *data,
> + struct list_head *list,
> + char *bpf_file_name);
> +/* Provide this function for perf test */
> +struct bpf_object;
> +int parse_events_load_bpf_obj(struct parse_events_evlist *data,
> + struct list_head *list,
> + struct bpf_object *obj);
> int parse_events_add_numeric(struct parse_events_evlist *data,
> struct list_head *list,
> u32 type, u64 config,
> diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
> index be24457..5e5d31a 100644
> --- a/tools/perf/util/parse-events.l
> +++ b/tools/perf/util/parse-events.l
> @@ -115,6 +115,7 @@ do { \
> group [^,{}/]*[{][^}]*[}][^,{}/]*
> event_pmu [^,{}/]+[/][^/]*[/][^,{}/]*
> event [^,{}/]+
> +bpf_object .*\.(o|bpf)
>
> num_dec [0-9]+
> num_hex 0x[a-fA-F0-9]+
> @@ -159,6 +160,7 @@ modifier_bp [rwx]{1,3}
> }
>
> {event_pmu} |
> +{bpf_object} |
> {event} {
> BEGIN(INITIAL);
> REWIND(1);
> @@ -264,6 +266,7 @@ r{num_raw_hex} { return raw(yyscanner); }
> {num_hex} { return value(yyscanner, 16); }
>
> {modifier_event} { return str(yyscanner, PE_MODIFIER_EVENT); }
> +{bpf_object} { return str(yyscanner, PE_BPF_OBJECT); }
> {name} { return pmu_str_check(yyscanner); }
> "/" { BEGIN(config); return '/'; }
> - { return '-'; }
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index ae6af26..497f19b 100644
> --- a/tools/perf/util/parse-events.y
> +++ b/tools/perf/util/parse-events.y
> @@ -42,6 +42,7 @@ static inc_group_count(struct list_head *list,
> %token PE_VALUE PE_VALUE_SYM_HW PE_VALUE_SYM_SW PE_RAW PE_TERM
> %token PE_EVENT_NAME
> %token PE_NAME
> +%token PE_BPF_OBJECT
> %token PE_MODIFIER_EVENT PE_MODIFIER_BP
> %token PE_NAME_CACHE_TYPE PE_NAME_CACHE_OP_RESULT
> %token PE_PREFIX_MEM PE_PREFIX_RAW PE_PREFIX_GROUP
> @@ -53,6 +54,7 @@ static inc_group_count(struct list_head *list,
> %type <num> PE_RAW
> %type <num> PE_TERM
> %type <str> PE_NAME
> +%type <str> PE_BPF_OBJECT
> %type <str> PE_NAME_CACHE_TYPE
> %type <str> PE_NAME_CACHE_OP_RESULT
> %type <str> PE_MODIFIER_EVENT
> @@ -70,6 +72,7 @@ static inc_group_count(struct list_head *list,
> %type <tracepoint_name> tracepoint_name
> %type <head> event_legacy_numeric
> %type <head> event_legacy_raw
> +%type <head> event_bpf_file
> %type <head> event_def
> %type <head> event_mod
> %type <head> event_name
> @@ -203,7 +206,8 @@ event_def: event_pmu |
> event_legacy_mem |
> event_legacy_tracepoint sep_dc |
> event_legacy_numeric sep_dc |
> - event_legacy_raw sep_dc
> + event_legacy_raw sep_dc |
> + event_bpf_file
>
> event_pmu:
> PE_NAME '/' event_config '/'
> @@ -449,6 +453,18 @@ PE_RAW
> $$ = list;
> }
>
> +event_bpf_file:
> +PE_BPF_OBJECT
> +{
> + struct parse_events_evlist *data = _data;
> + struct parse_events_error *error = data->error;
> + struct list_head *list;
> +
> + ALLOC_LIST(list);
> + ABORT_ON(parse_events_load_bpf(data, list, $1));
> + $$ = list;
> +}
> +
> start_terms: event_config
> {
> struct parse_events_terms *data = _data;
> --
> 1.8.3.4
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Next message: Austin S Hemmelgarn: "Possible bug in DM-RAID."
Previous message: Murali Karicheri: "Re: [PATCH v1 1/2] phy: keystone: serdes driver for gbe 10gbe and pcie"
Next in thread: Arnaldo Carvalho de Melo: "Re: [PATCH 03/31] perf tools: Enable passing bpf object file to --event"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]