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perf tools: Enable indices setting syntax for BPF map

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This patch introduces a new syntax to perf event parser:

 # perf record -e './test_bpf_map_3.c/map:channel.value[0,1,2,3...5]=101/' usleep 2

By utilizing the basic facilities in bpf-loader.c which allow setting
different slots in a BPF map separately, the newly introduced syntax
allows perf to control specific elements in a BPF map.

Test result:

  # cat ./test_bpf_map_3.c
  /************************ BEGIN **************************/
  #include <uapi/linux/bpf.h>
  #define SEC(NAME) __attribute__((section(NAME), used))
  struct bpf_map_def {
	unsigned int type;
	unsigned int key_size;
	unsigned int value_size;
	unsigned int max_entries;
  };
  static void *(*map_lookup_elem)(struct bpf_map_def *, void *) =
 	(void *)BPF_FUNC_map_lookup_elem;
  static int (*trace_printk)(const char *fmt, int fmt_size, ...) =
 	(void *)BPF_FUNC_trace_printk;
  struct bpf_map_def SEC("maps") channel = {
 	.type = BPF_MAP_TYPE_ARRAY,
 	.key_size = sizeof(int),
 	.value_size = sizeof(unsigned char),
 	.max_entries = 100,
  };
  SEC("func=hrtimer_nanosleep rqtp->tv_nsec")
  int func(void *ctx, int err, long nsec)
  {
 	char fmt[] = "%ld\n";
 	long usec = nsec * 0x10624dd3 >> 38; // nsec / 1000
 	int key = (int)usec;
 	unsigned char *pval = map_lookup_elem(&channel, &key);

 	if (!pval)
 		return 0;
 	trace_printk(fmt, sizeof(fmt), (unsigned char)*pval);
 	return 0;
  }
  char _license[] SEC("license") = "GPL";
  int _version SEC("version") = LINUX_VERSION_CODE;
  /************************* END ***************************/

Normal case:

  # echo "" > /sys/kernel/debug/tracing/trace
  # ./perf record -e './test_bpf_map_3.c/map:channel.value[0,1,2,3...5]=101/' usleep 2
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.012 MB perf.data ]
  # cat /sys/kernel/debug/tracing/trace | grep usleep
            usleep-405   [004] d... 2745423.547822: : 101
  # ./perf record -e './test_bpf_map_3.c/map:channel.value[0...9,20...29]=102,map:channel.value[10...19]=103/' usleep 3
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.012 MB perf.data ]
  # ./perf record -e './test_bpf_map_3.c/map:channel.value[0...9,20...29]=102,map:channel.value[10...19]=103/' usleep 15
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.012 MB perf.data ]
  # cat /sys/kernel/debug/tracing/trace | grep usleep
            usleep-405   [004] d... 2745423.547822: : 101
            usleep-655   [006] d... 2745434.122814: : 102
            usleep-904   [006] d... 2745439.916264: : 103
  # ./perf record -e './test_bpf_map_3.c/map:channel.value[all]=104/' usleep 99
  # cat /sys/kernel/debug/tracing/trace | grep usleep
            usleep-405   [004] d... 2745423.547822: : 101
            usleep-655   [006] d... 2745434.122814: : 102
            usleep-904   [006] d... 2745439.916264: : 103
            usleep-1537  [003] d... 2745538.053737: : 104

Error case:

  # ./perf record -e './test_bpf_map_3.c/map:channel.value[10...1000]=104/' usleep 99
  event syntax error: '..annel.value[10...1000]=104/'
                                   \___ Index too large
  Hint:	Valid config terms:
      	map:[<arraymap>].value<indices>=[value]
      	map:[<eventmap>].event<indices>=[event]

      	where <indices> is something like [0,3...5] or [all]
      	(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

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.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: 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/1456132275-98875-9-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Wang Nan 2016-02-22 09:10:35 +00:00 committed by Arnaldo Carvalho de Melo
parent 2d055bf253
commit e571e029bd
3 changed files with 100 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
tools/perf/util/parse-events.c
View File

@ -704,9 +704,10 @@ parse_events_config_bpf(struct parse_events_evlist *data,
sizeof(errbuf));
data->error->help = strdup(
"Hint:\tValid config terms:\n"
" \tmap:[<arraymap>].value=[value]\n"
" \tmap:[<eventmap>].event=[event]\n"
" \tmap:[<arraymap>].value<indices>=[value]\n"
" \tmap:[<eventmap>].event<indices>=[event]\n"
"\n"
" \twhere <indices> is something like [0,3...5] or [all]\n"
" \t(add -v to see detail)");
data->error->str = strdup(errbuf);
if (err == -BPF_LOADER_ERRNO__OBJCONF_MAP_VALUE)

13
tools/perf/util/parse-events.l
View File

@ -9,8 +9,8 @@
%{
#include <errno.h>
#include "../perf.h"
#include "parse-events-bison.h"
#include "parse-events.h"
#include "parse-events-bison.h"
char *parse_events_get_text(yyscan_t yyscanner);
YYSTYPE *parse_events_get_lval(yyscan_t yyscanner);
@ -111,6 +111,7 @@ do { \
%x mem
%s config
%x event
%x array
group [^,{}/]*[{][^}]*[}][^,{}/]*
event_pmu [^,{}/]+[/][^/]*[/][^,{}/]*
@ -176,6 +177,14 @@ modifier_bp [rwx]{1,3}
}
<array>{
"]" { BEGIN(config); return ']'; }
{num_dec} { return value(yyscanner, 10); }
{num_hex} { return value(yyscanner, 16); }
, { return ','; }
"\.\.\." { return PE_ARRAY_RANGE; }
}
<config>{
/*
* Please update config_term_names when new static term is added.
@ -195,6 +204,8 @@ no-inherit { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_NOINHERIT); }
, { return ','; }
"/" { BEGIN(INITIAL); return '/'; }
{name_minus} { return str(yyscanner, PE_NAME); }
\[all\] { return PE_ARRAY_ALL; }
"[" { BEGIN(array); return '['; }
}
<mem>{

85
tools/perf/util/parse-events.y
View File

@ -48,6 +48,7 @@ static inc_group_count(struct list_head *list,
%token PE_PREFIX_MEM PE_PREFIX_RAW PE_PREFIX_GROUP
%token PE_ERROR
%token PE_PMU_EVENT_PRE PE_PMU_EVENT_SUF PE_KERNEL_PMU_EVENT
%token PE_ARRAY_ALL PE_ARRAY_RANGE
%type <num> PE_VALUE
%type <num> PE_VALUE_SYM_HW
%type <num> PE_VALUE_SYM_SW
@ -83,6 +84,9 @@ static inc_group_count(struct list_head *list,
%type <head> group_def
%type <head> group
%type <head> groups
%type <array> array
%type <array> array_term
%type <array> array_terms
%union
{
@ -94,6 +98,7 @@ static inc_group_count(struct list_head *list,
char *sys;
char *event;
} tracepoint_name;
struct parse_events_array array;
}
%%
@ -572,6 +577,86 @@ PE_TERM
ABORT_ON(parse_events_term__num(&term, (int)$1, NULL, 1, &@1, NULL));
$$ = term;
}
|
PE_NAME array '=' PE_NAME
{
struct parse_events_term *term;
int i;
ABORT_ON(parse_events_term__str(&term, PARSE_EVENTS__TERM_TYPE_USER,
$1, $4, &@1, &@4));
term->array = $2;
$$ = term;
}
|
PE_NAME array '=' PE_VALUE
{
struct parse_events_term *term;
ABORT_ON(parse_events_term__num(&term, PARSE_EVENTS__TERM_TYPE_USER,
$1, $4, &@1, &@4));
term->array = $2;
$$ = term;
}
array:
'[' array_terms ']'
{
$$ = $2;
}
|
PE_ARRAY_ALL
{
$$.nr_ranges = 0;
$$.ranges = NULL;
}
array_terms:
array_terms ',' array_term
{
struct parse_events_array new_array;
new_array.nr_ranges = $1.nr_ranges + $3.nr_ranges;
new_array.ranges = malloc(sizeof(new_array.ranges[0]) *
new_array.nr_ranges);
ABORT_ON(!new_array.ranges);
memcpy(&new_array.ranges[0], $1.ranges,
$1.nr_ranges * sizeof(new_array.ranges[0]));
memcpy(&new_array.ranges[$1.nr_ranges], $3.ranges,
$3.nr_ranges * sizeof(new_array.ranges[0]));
free($1.ranges);
free($3.ranges);
$$ = new_array;
}
|
array_term
array_term:
PE_VALUE
{
struct parse_events_array array;
array.nr_ranges = 1;
array.ranges = malloc(sizeof(array.ranges[0]));
ABORT_ON(!array.ranges);
array.ranges[0].start = $1;
array.ranges[0].length = 1;
$$ = array;
}
|
PE_VALUE PE_ARRAY_RANGE PE_VALUE
{
struct parse_events_array array;
ABORT_ON($3 < $1);
array.nr_ranges = 1;
array.ranges = malloc(sizeof(array.ranges[0]));
ABORT_ON(!array.ranges);
array.ranges[0].start = $1;
array.ranges[0].length = $3 - $1 + 1;
$$ = array;
}
sep_dc: ':' |