[PATCH 12/16] perf tools: Support setting different slots in a BPF map separately

Wang Nan
2015-11-24T13:37:59Z

This patch introduces basic facilities to support config different
slots in a BPF map one by one.

array.nr_ranges and array.ranges are introduced into 'struct
parse_events_term', where ranges is an array of indices range (start,
length) which will be configured by this config term. nr_ranges
is the size of the array. The array is passed to 'struct bpf_map_priv'.
To indicate the new type of configuration, BPF_MAP_KEY_RANGES is
added as a new key type. bpf_map_config_foreach_key() is extended to
iterate over those indices instead of all possible keys.

Code in this commit will be enabled by following commit which enables
the indices syntax for array configuration.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
---
tools/perf/util/bpf-loader.c | 133 ++++++++++++++++++++++++++++++++++++++---
tools/perf/util/bpf-loader.h | 1 +
tools/perf/util/parse-events.c | 33 +++++++++-
tools/perf/util/parse-events.h | 12 ++++
4 files changed, 171 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index a6e4bde..185d2cf 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -17,6 +17,7 @@
#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) \
@@ -747,6 +748,7 @@ enum bpf_map_op_type {

enum bpf_map_key_type {
BPF_MAP_KEY_ALL,
+ BPF_MAP_KEY_RANGES,
};

struct bpf_map_op {
@@ -754,6 +756,9 @@ struct bpf_map_op {
enum bpf_map_op_type op_type;
enum bpf_map_key_type key_type;
union {
+ struct parse_events_array array;
+ } k;
+ union {
u64 value;
struct perf_evsel *evsel;
} v;
@@ -768,6 +773,8 @@ bpf_map_op__free(struct bpf_map_op *op)
{
if (!list_is_singular(&op->list))
list_del(&op->list);
+ if (op->key_type == BPF_MAP_KEY_RANGES)
+ parse_events__clear_array(&op->k.array);
free(op);
}

@@ -783,8 +790,31 @@ bpf_map_priv__clear(struct bpf_map *map __maybe_unused,
free(priv);
}

+static int
+bpf_map_op_setkey(struct bpf_map_op *op, struct parse_events_term *term,
+ const char *map_name)
+{
+ op->key_type = BPF_MAP_KEY_ALL;
+
+ if (term->array.nr_ranges) {
+ size_t memsz = term->array.nr_ranges *
+ sizeof(op->k.array.ranges[0]);
+
+ op->k.array.ranges = malloc(memsz);
+ if (!op->k.array.ranges) {
+ pr_debug("No enough memory to alloc indices for %s\n",
+ map_name);
+ return -ENOMEM;
+ }
+ memcpy(op->k.array.ranges, term->array.ranges, memsz);
+ op->key_type = BPF_MAP_KEY_RANGES;
+ op->k.array.nr_ranges = term->array.nr_ranges;
+ }
+ return 0;
+}
+
static struct bpf_map_op *
-bpf_map_op__alloc(struct bpf_map *map)
+bpf_map_op__alloc(struct bpf_map *map, struct parse_events_term *term)
{
struct bpf_map_op *op;
struct bpf_map_priv *priv;
@@ -818,7 +848,12 @@ bpf_map_op__alloc(struct bpf_map *map)
return ERR_PTR(-ENOMEM);
}

- op->key_type = BPF_MAP_KEY_ALL;
+ err = bpf_map_op_setkey(op, term, map_name);
+ if (err) {
+ free(op);
+ return ERR_PTR(err);
+ }
+
list_add_tail(&op->list, &priv->ops_list);
return op;
}
@@ -861,7 +896,7 @@ bpf__obj_config_map_array_value(struct bpf_map *map,
return -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUESIZE;
}

- op = bpf_map_op__alloc(map);
+ op = bpf_map_op__alloc(map, term);
if (IS_ERR(op))
return PTR_ERR(op);
op->op_type = BPF_MAP_OP_SET_VALUE;
@@ -922,7 +957,7 @@ bpf__obj_config_map_array_event(struct bpf_map *map,
return -BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE;
}

- op = bpf_map_op__alloc(map);
+ op = bpf_map_op__alloc(map, term);
if (IS_ERR(op))
return PTR_ERR(op);

@@ -961,6 +996,44 @@ struct bpf_obj_config_map_func bpf_obj_config_map_funcs[] = {
};

static int
+config_map_indices_range_check(struct parse_events_term *term,
+ struct bpf_map *map,
+ const char *map_name)
+{
+ struct parse_events_array *array = &term->array;
+ struct bpf_map_def def;
+ unsigned int i;
+ int err;
+
+ if (!array->nr_ranges)
+ return 0;
+ if (!array->ranges) {
+ pr_debug("ERROR: map %s: array->nr_ranges is %d but range array is NULL\n",
+ map_name, (int)array->nr_ranges);
+ return -BPF_LOADER_ERRNO__INTERNAL;
+ }
+
+ err = bpf_map__get_def(map, &def);
+ if (err) {
+ pr_debug("ERROR: Unable to get map definition from '%s'\n",
+ map_name);
+ return -BPF_LOADER_ERRNO__INTERNAL;
+ }
+
+ for (i = 0; i < array->nr_ranges; i++) {
+ unsigned int start = array->ranges[i].start;
+ size_t length = array->ranges[i].length;
+ unsigned int idx = start + length - 1;
+
+ if (idx >= def.max_entries) {
+ pr_debug("ERROR: index %d too large\n", idx);
+ return -BPF_LOADER_ERRNO__OBJCONF_MAP_IDX2BIG;
+ }
+ }
+ return 0;
+}
+
+static int
bpf__obj_config_map(struct bpf_object *obj,
struct parse_events_term *term,
struct perf_evlist *evlist,
@@ -996,6 +1069,13 @@ bpf__obj_config_map(struct bpf_object *obj,
}

*key_scan_pos += map_opt - map_name;
+
+ *key_scan_pos += strlen(map_opt);
+ err = config_map_indices_range_check(term, map, map_name);
+ if (err)
+ goto out;
+ *key_scan_pos -= strlen(map_opt);
+
for (i = 0; i < ARRAY_SIZE(bpf_obj_config_map_funcs); i++) {
struct bpf_obj_config_map_func *func =
&bpf_obj_config_map_funcs[i];
@@ -1066,6 +1146,33 @@ foreach_key_array_all(map_config_func_t func,
}

static int
+foreach_key_array_ranges(map_config_func_t func, void *arg,
+ const char *name, int map_fd,
+ struct bpf_map_def *pdef,
+ struct bpf_map_op *op)
+{
+ unsigned int i, j;
+ int err;
+
+ for (i = 0; i < op->k.array.nr_ranges; i++) {
+ unsigned int start = op->k.array.ranges[i].start;
+ size_t length = op->k.array.ranges[i].length;
+
+ for (j = 0; j < length; j++) {
+ unsigned int idx = start + j;
+
+ err = func(name, map_fd, pdef, op, &idx, arg);
+ if (err) {
+ pr_debug("ERROR: failed to insert value to %s[%u]\n",
+ name, idx);
+ return err;
+ }
+ }
+ }
+ return 0;
+}
+
+static int
bpf_map_config_foreach_key(struct bpf_map *map,
map_config_func_t func,
void *arg)
@@ -1105,13 +1212,24 @@ bpf_map_config_foreach_key(struct bpf_map *map,
case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
switch (op->key_type) {
case BPF_MAP_KEY_ALL:
- return foreach_key_array_all(func, arg, name,
- map_fd, &def, op);
+ err = foreach_key_array_all(func, arg, name,
+ map_fd, &def, op);
+ if (err)
+ return err;
+ break;
+ case BPF_MAP_KEY_RANGES:
+ err = foreach_key_array_ranges(func, arg, name,
+ map_fd, &def,
+ op);
+ if (err)
+ return err;
+ break;
default:
pr_debug("ERROR: keytype for map '%s' invalid\n",
name);
return -BPF_LOADER_ERRNO__INTERNAL;
- }
+ }
+ break;
default:
pr_debug("ERROR: type of '%s' incorrect\n", name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE;
@@ -1298,6 +1416,7 @@ static const char *bpf_loader_strerror_table[NR_ERRNO] = {
[ERRCODE_OFFSET(OBJCONF_MAP_EVTDIM)] = "Event dimension too large",
[ERRCODE_OFFSET(OBJCONF_MAP_EVTINH)] = "Doesn't support inherit event",
[ERRCODE_OFFSET(OBJCONF_MAP_EVTTYPE)] = "Wrong event type for map",
+ [ERRCODE_OFFSET(OBJCONF_MAP_IDX2BIG)] = "Index too large",
};

static int
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index c9ce792..30ee519 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -38,6 +38,7 @@ enum bpf_loader_errno {
BPF_LOADER_ERRNO__OBJCONF_MAP_EVTDIM, /* Event dimension too large */
BPF_LOADER_ERRNO__OBJCONF_MAP_EVTINH, /* Doesn't support inherit event */
BPF_LOADER_ERRNO__OBJCONF_MAP_EVTTYPE, /* Wrong event type for map */
+ BPF_LOADER_ERRNO__OBJCONF_MAP_IDX2BIG, /* Index too large */
__BPF_LOADER_ERRNO__END,
};

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 799bfd2..ef794c5 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -2144,8 +2144,39 @@ void parse_events__free_terms(struct list_head *terms)
{
struct parse_events_term *term, *h;

- list_for_each_entry_safe(term, h, terms, list)
+ list_for_each_entry_safe(term, h, terms, list) {
+ if (term->array.nr_ranges)
+ free(term->array.ranges);
free(term);
+ }
+}
+
+int parse_events__merge_arrays(struct parse_events_array *dest,
+ struct parse_events_array *another)
+{
+ struct parse_events_array new;
+
+ if (!dest || !another)
+ return -EINVAL;
+
+ new.nr_ranges = dest->nr_ranges + another->nr_ranges;
+ new.ranges = malloc(sizeof(new.ranges[0]) * new.nr_ranges);
+ if (!new.ranges)
+ return -ENOMEM;
+
+ memcpy(&new.ranges[0], dest->ranges,
+ sizeof(new.ranges[0]) * dest->nr_ranges);
+ memcpy(&new.ranges[dest->nr_ranges], another->ranges,
+ sizeof(new.ranges[0]) * another->nr_ranges);
+ free(dest->ranges);
+ free(another->ranges);
+ *dest = new;
+ return 0;
+}
+
+void parse_events__clear_array(struct parse_events_array *a)
+{
+ free(a->ranges);
}

void parse_events_evlist_error(struct parse_events_evlist *data,
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 20ad3c2..c34615f 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -71,8 +71,17 @@ enum {
PARSE_EVENTS__TERM_TYPE_INHERIT
};

+struct parse_events_array {
+ size_t nr_ranges;
+ struct {
+ unsigned int start;
+ size_t length;
+ } *ranges;
+};
+
struct parse_events_term {
char *config;
+ struct parse_events_array array;
union {
char *str;
u64 num;
@@ -117,6 +126,9 @@ int parse_events_term__sym_hw(struct parse_events_term **term,
int parse_events_term__clone(struct parse_events_term **new,
struct parse_events_term *term);
void parse_events__free_terms(struct list_head *terms);
+int parse_events__merge_arrays(struct parse_events_array *dest,
+ struct parse_events_array *another);
+void parse_events__clear_array(struct parse_events_array *a);
int parse_events__modifier_event(struct list_head *list, char *str, bool add);
int parse_events__modifier_group(struct list_head *list, char *event_mod);
int parse_events_name(struct list_head *list, char *name);
--
1.8.3.4