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perf tools: Support setting different slots in a BPF map separately
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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: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Cody P Schafer <dev@codyps.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jeremie.galarneau@efficios.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kirill Smelkov <kirr@nexedi.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1456132275-98875-8-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Wang Nan authored and Arnaldo Carvalho de Melo committed Feb 22, 2016
1 parent 7630b3e commit 2d055bf
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Showing 4 changed files with 137 additions and 9 deletions.
128 changes: 119 additions & 9 deletions tools/perf/util/bpf-loader.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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) \
Expand Down Expand Up @@ -747,12 +748,16 @@ enum bpf_map_op_type {

enum bpf_map_key_type {
BPF_MAP_KEY_ALL,
BPF_MAP_KEY_RANGES,
};

struct bpf_map_op {
struct list_head list;
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;
Expand All @@ -768,6 +773,8 @@ bpf_map_op__delete(struct bpf_map_op *op)
{
if (!list_empty(&op->list))
list_del(&op->list);
if (op->key_type == BPF_MAP_KEY_RANGES)
parse_events__clear_array(&op->k.array);
free(op);
}

Expand All @@ -792,10 +799,33 @@ 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)
{
op->key_type = BPF_MAP_KEY_ALL;
if (!term)
return 0;

if (term->array.nr_ranges) {
size_t memsz = term->array.nr_ranges *
sizeof(op->k.array.ranges[0]);

op->k.array.ranges = memdup(term->array.ranges, memsz);
if (!op->k.array.ranges) {
pr_debug("No enough memory to alloc indices for map\n");
return -ENOMEM;
}
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__new(void)
bpf_map_op__new(struct parse_events_term *term)
{
struct bpf_map_op *op;
int err;

op = zalloc(sizeof(*op));
if (!op) {
Expand All @@ -804,7 +834,11 @@ bpf_map_op__new(void)
}
INIT_LIST_HEAD(&op->list);

op->key_type = BPF_MAP_KEY_ALL;
err = bpf_map_op_setkey(op, term);
if (err) {
free(op);
return ERR_PTR(err);
}
return op;
}

Expand Down Expand Up @@ -841,12 +875,12 @@ bpf_map__add_op(struct bpf_map *map, struct bpf_map_op *op)
}

static struct bpf_map_op *
bpf_map__add_newop(struct bpf_map *map)
bpf_map__add_newop(struct bpf_map *map, struct parse_events_term *term)
{
struct bpf_map_op *op;
int err;

op = bpf_map_op__new();
op = bpf_map_op__new(term);
if (IS_ERR(op))
return op;

Expand Down Expand Up @@ -896,7 +930,7 @@ __bpf_map__config_value(struct bpf_map *map,
return -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUESIZE;
}

op = bpf_map__add_newop(map);
op = bpf_map__add_newop(map, term);
if (IS_ERR(op))
return PTR_ERR(op);
op->op_type = BPF_MAP_OP_SET_VALUE;
Expand Down Expand Up @@ -958,7 +992,7 @@ __bpf_map__config_event(struct bpf_map *map,
return -BPF_LOADER_ERRNO__OBJCONF_MAP_TYPE;
}

op = bpf_map__add_newop(map);
op = bpf_map__add_newop(map, term);
if (IS_ERR(op))
return PTR_ERR(op);
op->op_type = BPF_MAP_OP_SET_EVSEL;
Expand Down Expand Up @@ -995,6 +1029,44 @@ struct bpf_obj_config__map_func bpf_obj_config__map_funcs[] = {
{"event", bpf_map__config_event},
};

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,
Expand Down Expand Up @@ -1030,7 +1102,12 @@ bpf__obj_config_map(struct bpf_object *obj,
goto out;
}

*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];
Expand Down Expand Up @@ -1099,6 +1176,33 @@ foreach_key_array_all(map_config_func_t func,
return 0;
}

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,
Expand Down Expand Up @@ -1141,14 +1245,19 @@ bpf_map_config_foreach_key(struct bpf_map *map,
case BPF_MAP_KEY_ALL:
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);
break;
default:
pr_debug("ERROR: keytype for map '%s' invalid\n",
name);
return -BPF_LOADER_ERRNO__INTERNAL;
}
if (err)
return err;
break;
default:
pr_debug("ERROR: type of '%s' incorrect\n", name);
Expand Down Expand Up @@ -1336,6 +1445,7 @@ 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
Expand Down
1 change: 1 addition & 0 deletions tools/perf/util/bpf-loader.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
};

Expand Down
7 changes: 7 additions & 0 deletions tools/perf/util/parse-events.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2211,6 +2211,8 @@ void parse_events_terms__purge(struct list_head *terms)
struct parse_events_term *term, *h;

list_for_each_entry_safe(term, h, terms, list) {
if (term->array.nr_ranges)
free(term->array.ranges);
list_del_init(&term->list);
free(term);
}
Expand All @@ -2224,6 +2226,11 @@ void parse_events_terms__delete(struct list_head *terms)
free(terms);
}

void parse_events__clear_array(struct parse_events_array *a)
{
free(a->ranges);
}

void parse_events_evlist_error(struct parse_events_evlist *data,
int idx, const char *str)
{
Expand Down
10 changes: 10 additions & 0 deletions tools/perf/util/parse-events.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -72,8 +72,17 @@ enum {
__PARSE_EVENTS__TERM_TYPE_NR,
};

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;
Expand Down Expand Up @@ -120,6 +129,7 @@ int parse_events_term__clone(struct parse_events_term **new,
struct parse_events_term *term);
void parse_events_terms__delete(struct list_head *terms);
void parse_events_terms__purge(struct list_head *terms);
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);
Expand Down

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