Messages in this thread Patch in this message | | | From | Wang Nan <> | Subject | [RFC PATCH 1/7] perf tools: Add API to config maps in bpf object | Date | Sat, 17 Oct 2015 10:48:24 +0000 |
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bpf__config_obj() is introduced as a core API to config BPF object after loading. One configuration option of maps is introduced. After this patch BPF object can accept configuration like:
maps.my_map.value=1234
This patch is more complex than the work it really does because the consideration of extension. In designing of BPF map configuration, following things should be considered:
1. Array indics selection: perf should allow user setting different value to different slots in an array, with syntax like: maps.my_map.value[0,3-6]=1234;
2. Type of value: integer is not the only valid value type. Perf event can also be put into a map after commit 35578d7984003097af2b1e3 (bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter);
3. For hash table, it is possible to use string or other as key;
4. It is possible that map configuration is unable to be setup during parsing. Perf event is an example.
Therefore, this patch does tie following thing for extension:
1. Instead of update map element during parsing, this patch stores map config options in 'struct bpf_map_priv'. Following patches would apply those configs at proper time;
2. Make 'struct bpf_map_priv' extensible so following patches can add new key and value operations;
3. Use bpf_config_map_funcs array to support more maps configuration.
Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: He Kuang <hekuang@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kaixu Xia <xiakaixu@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/n/ebpf-36xcrahy9n0ayc05mu7aajpk@git.kernel.org --- tools/perf/util/bpf-loader.c | 180 +++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/bpf-loader.h | 27 +++++++ 2 files changed, 207 insertions(+)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c index 73ff9a9..a5a1c36 100644 --- a/tools/perf/util/bpf-loader.c +++ b/tools/perf/util/bpf-loader.c @@ -10,11 +10,13 @@ #include <linux/err.h> #include "perf.h" #include "debug.h" +#include "util.h" #include "bpf-loader.h" #include "bpf-prologue.h" #include "llvm-utils.h" #include "probe-event.h" #include "probe-finder.h" // for MAX_PROBES +#include "parse-events.h" #include "llvm-utils.h" #define DEFINE_PRINT_FN(name, level) \ @@ -633,6 +635,170 @@ int bpf__foreach_tev(struct bpf_object *obj, return 0; } +enum bpf_map_priv_key_type { + BPF_MAP_PRIV_KEY_ALL, +}; + +enum bpf_map_priv_value_type { + BPF_MAP_PRIV_VAL_VALUE, +}; + +struct bpf_map_priv { + struct { + enum bpf_map_priv_key_type type; + } key; + + struct { + enum bpf_map_priv_value_type type; + union { + u64 val; + }; + } value; +}; + +static void +bpf_map_priv__clear(struct bpf_map *map __maybe_unused, + void *_priv) +{ + struct bpf_map_priv *priv = _priv; + + free(priv); +} + +static int +bpf__config_obj_map_array_value(struct bpf_map *map, + struct parse_events_term *term) +{ + struct bpf_map_priv *priv; + struct bpf_map_def def; + const char *map_name; + int err; + + map_name = bpf_map__get_name(map); + + err = bpf_map__get_def(map, &def); + if (err) { + pr_debug("Unable to get map definition from '%s'\n", + map_name); + return -EINVAL; + } + + if (def.type != BPF_MAP_TYPE_ARRAY) { + pr_debug("Map %s type is not BPF_MAP_TYPE_ARRAY\n", + map_name); + return -EBADF; + } + if (def.key_size < sizeof(unsigned int)) { + pr_debug("Map %s has incorrect key size\n", map_name); + return -EINVAL; + } + switch (def.value_size) { + case 1: + case 2: + case 4: + case 8: + break; + default: + pr_debug("Map %s has incorrect value size\n", map_name); + return -EINVAL; + } + + priv = zalloc(sizeof(*priv)); + if (!priv) { + pr_debug("No enough memory to alloc map private\n"); + return -ENOMEM; + } + + priv->key.type = BPF_MAP_PRIV_KEY_ALL; + priv->value.type = BPF_MAP_PRIV_VAL_VALUE; + priv->value.val = term->val.num; + return bpf_map__set_private(map, priv, bpf_map_priv__clear); +} + +static int +bpf__config_obj_map_value(struct bpf_map *map, + struct parse_events_term *term, + struct perf_evlist *evlist __maybe_unused) +{ + if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) + return bpf__config_obj_map_array_value(map, term); + + pr_debug("ERROR: wrong value type\n"); + return -EINVAL; +} + +struct bpf_config_map_func { + const char *config_opt; + int (*config_func)(struct bpf_map *, struct parse_events_term *, + struct perf_evlist *); +}; + +struct bpf_config_map_func bpf_config_map_funcs[] = { + {"value", bpf__config_obj_map_value}, +}; + +static int +bpf__config_obj_map(struct bpf_object *obj, + struct parse_events_term *term, + struct perf_evlist *evlist) +{ + /* key is "maps.<mapname>.<config opt>" */ + char *map_name = strdup(term->config + sizeof("maps.") - 1); + struct bpf_map *map; + int err = -ENOENT; + char *map_opt; + size_t i; + + if (!map_name) + return -ENOMEM; + + map_opt = strchr(map_name, '.'); + if (!map_opt) { + pr_debug("ERROR: Invalid map config: %s\n", map_name); + goto out; + } + + *map_opt++ = '\0'; + if (*map_opt == '\0') { + pr_debug("ERROR: Invalid map option: %s\n", term->config); + goto out; + } + + map = bpf_object__get_map_by_name(obj, map_name); + if (!map) { + pr_debug("ERROR: Map %s doesn't exist\n", map_name); + goto out; + } + + for (i = 0; i < ARRAY_SIZE(bpf_config_map_funcs); i++) { + struct bpf_config_map_func *func = &bpf_config_map_funcs[i]; + + if (strcmp(map_opt, func->config_opt) == 0) { + err = func->config_func(map, term, evlist); + goto out; + } + } + + pr_debug("ERROR: invalid config option '%s' for maps\n", + map_opt); + err = -ENOENT; +out: + free(map_name); + return err; +} + +int bpf__config_obj(struct bpf_object *obj, + struct parse_events_term *term, + struct perf_evlist *evlist) +{ + if (!obj || !term || !term->config) + return -ENODEV; + + if (!prefixcmp(term->config, "maps.")) + return bpf__config_obj_map(obj, term, evlist); + return -ENODEV; +} + #define bpf__strerror_head(err, buf, size) \ char sbuf[STRERR_BUFSIZE], *emsg;\ if (!size)\ @@ -675,3 +841,17 @@ int bpf__strerror_load(struct bpf_object *obj __maybe_unused, bpf__strerror_end(buf, size); return 0; } + +int bpf__strerror_config_obj(struct bpf_object *obj __maybe_unused, + struct parse_events_term *term, + struct perf_evlist *evlist __maybe_unused, + int err, char *buf, size_t size) +{ + bpf__strerror_head(err, buf, size); + bpf__strerror_entry(ENODEV, "Invalid config option: '%s'", term->config) + bpf__strerror_entry(ENOENT, "Config target in '%s' is invalid", term->config) + bpf__strerror_entry(EBADF, "Map type mismatch in '%s'", term->config) + bpf__strerror_entry(EINVAL, "Invalid config value") + bpf__strerror_end(buf, size); + return 0; +} diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h index d8f1945..dfec9b8 100644 --- a/tools/perf/util/bpf-loader.h +++ b/tools/perf/util/bpf-loader.h @@ -9,9 +9,11 @@ #include <linux/err.h> #include <string.h> #include "probe-event.h" +#include "evlist.h" #include "debug.h" struct bpf_object; +struct parse_events_term; #define PERF_BPF_PROBE_GROUP "perf_bpf_probe" typedef int (*bpf_prog_iter_callback_t)(struct probe_trace_event *tev, @@ -34,6 +36,13 @@ 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); + +int bpf__config_obj(struct bpf_object *obj, struct parse_events_term *term, + struct perf_evlist *evlist); +int bpf__strerror_config_obj(struct bpf_object *obj, + struct parse_events_term *term, + struct perf_evlist *evlist, + int err, char *buf, size_t size); #else static inline struct bpf_object * bpf__prepare_load(const char *filename __maybe_unused, @@ -65,6 +74,14 @@ bpf__foreach_tev(struct bpf_object *obj __maybe_unused, } static inline int +bpf__config_obj(struct bpf_object *obj __maybe_unused, + struct parse_events_term *term __maybe_unused, + struct perf_evlist *evlist __maybe_unused) +{ + return 0; +} + +static inline int __bpf_strerror(char *buf, size_t size) { if (!size) @@ -90,5 +107,15 @@ static inline int bpf__strerror_load(struct bpf_object *obj __maybe_unused, { return __bpf_strerror(buf, size); } + +static inline int +bpf__strerror_config_obj(struct bpf_object *obj __maybe_unused, + struct parse_events_term *term __maybe_unused, + struct perf_evlist *evlist __maybe_unused, + int err __maybe_unused, + char *buf, size_t size) +{ + return __bpf_strerror(buf, size); +} #endif #endif -- 1.8.3.4
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