[PATCH v3] perf parse-events: Set exclude_guest=1 for user-space counting

From: Jin Yao
Date: Thu Aug 13 2020 - 21:22:40 EST


Currently if we run 'perf record -e cycles:u', exclude_guest=0.

But it doesn't make sense in most cases that we request for
user-space counting but we also get the guest report.

Of course, we also need to consider perf kvm usage case that
authorized perf users on the host may only want to count guest
user space events. For example,

perf kvm --guest record -e cycles:u

When we have 'exclude_guest=1' for perf kvm usage, we may get
nothing from guest events.

To keep perf semantics consistent and clear, this patch sets
exclude_guest=1 for user-space counting but except for perf
kvm usage.

Before:
perf record -e cycles:u ./div
perf evlist -v
cycles:u: ..., exclude_kernel: 1, exclude_hv: 1, ...

After:
perf record -e cycles:u ./div
perf evlist -v
cycles:u: ..., exclude_kernel: 1, exclude_hv: 1, exclude_guest: 1, ...

Before:
perf kvm --guest record -e cycles:u -vvv

perf_event_attr:
size 120
{ sample_period, sample_freq } 4000
sample_type IP|TID|TIME|ID|CPU|PERIOD
read_format ID
disabled 1
inherit 1
exclude_kernel 1
exclude_hv 1
freq 1
sample_id_all 1

After:
perf kvm --guest record -e cycles:u -vvv

perf_event_attr:
size 120
{ sample_period, sample_freq } 4000
sample_type IP|TID|TIME|ID|CPU|PERIOD
read_format ID
disabled 1
inherit 1
exclude_kernel 1
exclude_hv 1
freq 1
sample_id_all 1

For Before/After, exclude_guest are both 0 for perf kvm usage.

perf test 6
6: Parse event definition strings : Ok

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
v3:
---
For perf kvm, if we have 'exclude_guest=1', we can't get guest
events. So we don't set 'exclude_guest=1' for perf kvm.

v2:
---
Fix the 'perf test 6' failure.

tools/perf/tests/parse-events.c | 4 ++--
tools/perf/util/parse-events.c | 3 +++
2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 7f9f87a470c3..aae0fd9045c1 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -719,7 +719,7 @@ static int test__group2(struct evlist *evlist)
TEST_ASSERT_VAL("wrong exclude_user", !evsel->core.attr.exclude_user);
TEST_ASSERT_VAL("wrong exclude_kernel", !evsel->core.attr.exclude_kernel);
TEST_ASSERT_VAL("wrong exclude_hv", evsel->core.attr.exclude_hv);
- TEST_ASSERT_VAL("wrong exclude guest", !evsel->core.attr.exclude_guest);
+ TEST_ASSERT_VAL("wrong exclude guest", evsel->core.attr.exclude_guest);
TEST_ASSERT_VAL("wrong exclude host", !evsel->core.attr.exclude_host);
TEST_ASSERT_VAL("wrong precise_ip", !evsel->core.attr.precise_ip);
TEST_ASSERT_VAL("wrong leader", evsel__is_group_leader(evsel));
@@ -842,7 +842,7 @@ static int test__group3(struct evlist *evlist __maybe_unused)
TEST_ASSERT_VAL("wrong exclude_user", !evsel->core.attr.exclude_user);
TEST_ASSERT_VAL("wrong exclude_kernel", evsel->core.attr.exclude_kernel);
TEST_ASSERT_VAL("wrong exclude_hv", evsel->core.attr.exclude_hv);
- TEST_ASSERT_VAL("wrong exclude guest", !evsel->core.attr.exclude_guest);
+ TEST_ASSERT_VAL("wrong exclude guest", evsel->core.attr.exclude_guest);
TEST_ASSERT_VAL("wrong exclude host", !evsel->core.attr.exclude_host);
TEST_ASSERT_VAL("wrong precise_ip", !evsel->core.attr.precise_ip);
TEST_ASSERT_VAL("wrong leader", evsel__is_group_leader(evsel));
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 9f7260e69113..ff4c23d2a0f3 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -37,6 +37,7 @@
#include "util/evsel_config.h"
#include "util/event.h"
#include "util/pfm.h"
+#include "perf.h"

#define MAX_NAME_LEN 100

@@ -1794,6 +1795,8 @@ static int get_event_modifier(struct event_modifier *mod, char *str,
if (*str == 'u') {
if (!exclude)
exclude = eu = ek = eh = 1;
+ if (!exclude_GH && !perf_guest)
+ eG = 1;
eu = 0;
} else if (*str == 'k') {
if (!exclude)
--
2.17.1