[RFC PATCH 6/7] perf tools: Enable indics setting syntax for BPF maps

From: Wang Nan
Date: Sat Oct 17 2015 - 06:49:52 EST


This patch introduce a new syntax to perf event parser:

# perf record -e bpf_file.c/maps.mymap.value[0,3-5,7]=1234/ ...

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.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxxxx>
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: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
---
tools/perf/util/parse-events.c | 4 +-
tools/perf/util/parse-events.l | 11 +++++
tools/perf/util/parse-events.y | 92 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 106 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 42ac1cb..a2af5a8 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -654,7 +654,9 @@ parse_events_config_bpf(struct parse_events_evlist *data,
err, errbuf, sizeof(errbuf));
data->error->help = strdup(
"Hint:\tValid config term:\n"
-" \tmaps.<mapname>.value\n"
+" \tmaps.<mapname>.value<indics>\n"
+"\n"
+" \twhere <indics> is something like [0,3-4]\n"
" \t(add -v to see detail)");
data->error->str = strdup(errbuf);
if (err == -EINVAL)
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index eeea4e1..0d92a4d 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -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 '-'; }
+}
+
<config>{
/*
* Please update parse_events_formats_error_string any time
@@ -194,6 +203,8 @@ stack-size { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_STACKSIZE); }
, { return ','; }
"/" { BEGIN(INITIAL); return '/'; }
{name_minus} { return str(yyscanner, PE_NAME); }
+\[all\] { return PE_ARRAY_ALL; }
+"[" { BEGIN(array); return '['; }
}

<mem>{
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index 255387a..81fe702 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -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
%type <num> PE_VALUE
%type <num> PE_VALUE_SYM_HW
%type <num> PE_VALUE_SYM_SW
@@ -84,6 +85,9 @@ 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
{
@@ -95,6 +99,10 @@ static inc_group_count(struct list_head *list,
char *sys;
char *event;
} tracepoint_name;
+ struct array {
+ size_t nr_indics;
+ u64 *indics;
+ } array;
}
%%

@@ -599,6 +607,90 @@ PE_TERM
ABORT_ON(parse_events_term__num(&term, (int)$1, NULL, 1, &@1, NULL));
$$ = term;
}
+|
+PE_NAME array '=' PE_NAME
+{
+ struct parse_events_term *term;
+ int i;
+
+ ABORT_ON(parse_events_term__str(&term, PARSE_EVENTS__TERM_TYPE_USER,
+ $1, $4, &@1, &@4));
+
+ term->nr_indics = $2.nr_indics;
+ term->indics = $2.indics;
+ $$ = 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->nr_indics = $2.nr_indics;
+ term->indics = $2.indics;
+ $$ = term;
+}
+
+array:
+'[' array_terms ']'
+{
+ $$ = $2;
+}
+|
+PE_ARRAY_ALL
+{
+ $$.nr_indics = 0;
+ $$.indics = NULL;
+}
+
+array_terms:
+array_terms ',' array_term
+{
+ struct array array = $1;
+ struct array new_array = $3;
+ u64 *new_indics;
+
+ new_indics = realloc(array.indics,
+ (array.nr_indics + new_array.nr_indics) * sizeof(u64));
+ ABORT_ON(!new_indics);
+
+ memcpy(&new_indics[array.nr_indics], new_array.indics,
+ sizeof(u64) * new_array.nr_indics);
+
+ array.nr_indics += new_array.nr_indics;
+ array.indics = new_indics;
+ free(new_array.indics);
+ $$ = array;
+}
+|
+array_term
+
+array_term:
+PE_VALUE
+{
+ struct array array;
+ array.nr_indics = 1;
+ array.indics = malloc(sizeof(u64));
+ ABORT_ON(!array.indics);
+ array.indics[0] = $1;
+ $$ = array;
+}
+|
+PE_VALUE '-' PE_VALUE
+{
+ struct array array;
+ int i;
+
+ ABORT_ON($3 < $1);
+ array.nr_indics = $3 - $1 + 1;
+ array.indics = malloc(sizeof(u64) * array.nr_indics);
+ ABORT_ON(!array.indics);
+
+ for (i = 0; i < array.nr_indics; i++)
+ array.indics[i] = $1 + i;
+ $$ = array;
+}

sep_dc: ':' |

--
1.8.3.4

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