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perf tools: Don't set attr.exclude_guest by default
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The exclude_guest in the event attribute is to limit profiling in the
host environment.  But I'm not sure why we want to set it by default
cause we don't care about it in most cases and I feel like it just
makes new PMU implementation complicated.

Of course it's useful for perf kvm command so I added the
exclude_GH_default variable to preserve the old behavior for perf kvm
and other commands like perf record and stat won't set the exclude bit.
This is helpful for AMD IBS case since having exclude_guest bit will
clear new feature bit due to the missing feature check logic.

  $ sysctl kernel.perf_event_paranoid
  kernel.perf_event_paranoid = 0

  $ perf record -W -e ibs_op// -vv true 2>&1 | grep switching
  switching off PERF_FORMAT_LOST support
  switching off weight struct support
  switching off bpf_event
  switching off ksymbol
  switching off cloexec flag
  switching off mmap2
  switching off exclude_guest, exclude_host

Intestingly, I found it sets the exclude_bit if "u" modifier is used.
I don't know why but it's neither intuitive nor consistent.  Let's
remove the bit there too.

Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: Atish Patra <atishp@atishpatra.org>
Cc: Mingwei Zhang <mizhang@google.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20241016062359.264929-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Namhyung Kim committed Oct 22, 2024
1 parent bb6e7cb commit 35c8d21
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Showing 6 changed files with 23 additions and 13 deletions.
1 change: 1 addition & 0 deletions tools/perf/builtin-kvm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2147,6 +2147,7 @@ int cmd_kvm(int argc, const char **argv)
"buildid-list", "stat", NULL };
const char *kvm_usage[] = { NULL, NULL };

exclude_GH_default = true;
perf_host = 0;
perf_guest = 1;

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18 changes: 9 additions & 9 deletions tools/perf/tests/parse-events.c
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Original file line number Diff line number Diff line change
Expand Up @@ -932,7 +932,7 @@ 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));
Expand All @@ -947,7 +947,7 @@ 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);
if (evsel__has_leader(evsel, leader))
Expand Down Expand Up @@ -1072,7 +1072,7 @@ 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));
Expand Down Expand Up @@ -1222,7 +1222,7 @@ static int test__group5(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));
Expand Down Expand Up @@ -1437,7 +1437,7 @@ static int test__leader_sample1(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 group name", !evsel->group_name);
Expand All @@ -1453,7 +1453,7 @@ static int test__leader_sample1(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__has_leader(evsel, leader));
Expand All @@ -1468,7 +1468,7 @@ static int test__leader_sample1(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 group name", !evsel->group_name);
Expand Down Expand Up @@ -1497,7 +1497,7 @@ static int test__leader_sample2(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 group name", !evsel->group_name);
Expand All @@ -1513,7 +1513,7 @@ static int test__leader_sample2(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 group name", !evsel->group_name);
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2 changes: 1 addition & 1 deletion tools/perf/tests/shell/attr/test-record-dummy-C0
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Original file line number Diff line number Diff line change
Expand Up @@ -37,7 +37,7 @@ precise_ip=0
mmap_data=0
sample_id_all=1
exclude_host=0
exclude_guest=1
exclude_guest=0
exclude_callchain_kernel=0
exclude_callchain_user=0
mmap2=1
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2 changes: 1 addition & 1 deletion tools/perf/util/parse-events.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1740,7 +1740,7 @@ static int parse_events__modifier_list(struct parse_events_state *parse_state,
if (mod.user) {
if (!exclude)
exclude = eu = ek = eh = 1;
if (!exclude_GH && !perf_guest)
if (!exclude_GH && !perf_guest && exclude_GH_default)
eG = 1;
eu = 0;
}
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10 changes: 8 additions & 2 deletions tools/perf/util/util.c
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Original file line number Diff line number Diff line change
Expand Up @@ -78,17 +78,23 @@ bool sysctl__nmi_watchdog_enabled(void)

bool test_attr__enabled;

bool exclude_GH_default;

bool perf_host = true;
bool perf_guest = false;

void event_attr_init(struct perf_event_attr *attr)
{
/* to capture ABI version */
attr->size = sizeof(*attr);

if (!exclude_GH_default)
return;

if (!perf_host)
attr->exclude_host = 1;
if (!perf_guest)
attr->exclude_guest = 1;
/* to capture ABI version */
attr->size = sizeof(*attr);
}

int mkdir_p(char *path, mode_t mode)
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3 changes: 3 additions & 0 deletions tools/perf/util/util.h
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,9 @@ extern const char perf_more_info_string[];

extern const char *input_name;

/* This will control if perf_{host,guest} will set attr.exclude_{host,guest}. */
extern bool exclude_GH_default;

extern bool perf_host;
extern bool perf_guest;

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