From: Kan Liang <[email protected]> With the hardware TopDown metrics feature, sample-read feature should be supported for a topdown group, e.g., sample a non-topdown event and read a topdown metric group. But the current perf record code errors out.
For a topdown metric group, the slots event must be the leader of the group, but the leader slots event doesn't support sampling. To support sample-read the topdown metric group, use the 2nd event of the group as the "leader" for the purposes of sampling. Only the platform with Topdown metic feature supports sample-read the topdown group. Add arch_topdown_sample_read() to indicate whether the topdown group supports sample-read. Signed-off-by: Kan Liang <[email protected]> --- tools/perf/arch/x86/util/topdown.c | 35 ++++++++++++++++++++++++++++++ tools/perf/util/record.c | 3 ++- tools/perf/util/topdown.c | 5 +++++ tools/perf/util/topdown.h | 2 ++ 4 files changed, 44 insertions(+), 1 deletion(-) diff --git a/tools/perf/arch/x86/util/topdown.c b/tools/perf/arch/x86/util/topdown.c index 597e963fb3e7..fcf1f9c17a44 100644 --- a/tools/perf/arch/x86/util/topdown.c +++ b/tools/perf/arch/x86/util/topdown.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include <stdio.h> #include "api/fs/fs.h" +#include "util/pmu.h" #include "util/topdown.h" /* @@ -26,3 +27,37 @@ void arch_topdown_group_warn(void) "nmi_watchdog enabled with topdown. May give wrong results.\n" "Disable with echo 0 > /proc/sys/kernel/nmi_watchdog\n"); } + +#define TOPDOWN_SLOTS 0x0400 + +static bool is_topdown_slots_event(struct evsel *counter) +{ + if (!counter->pmu_name) + return false; + + if (strcmp(counter->pmu_name, "cpu")) + return false; + + if (counter->core.attr.config == TOPDOWN_SLOTS) + return true; + + return false; +} + +/* + * Check whether a topdown group supports sample-read. + * + * Only Topdown metic supports sample-read. The slots + * event must be the leader of the topdown group. + */ + +bool arch_topdown_sample_read(struct evsel *leader) +{ + if (!pmu_have_event("cpu", "slots")) + return false; + + if (is_topdown_slots_event(leader)) + return true; + + return false; +} diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c index a4cc11592f6b..a857a13b0544 100644 --- a/tools/perf/util/record.c +++ b/tools/perf/util/record.c @@ -13,6 +13,7 @@ #include "util/perf_api_probe.h" #include "record.h" #include "../perf-sys.h" +#include "topdown.h" /* * evsel__config_leader_sampling() uses special rules for leader sampling. @@ -23,7 +24,7 @@ static struct evsel *evsel__read_sampler(struct evsel *evsel, struct evlist *evl { struct evsel *leader = evsel->leader; - if (evsel__is_aux_event(leader)) { + if (evsel__is_aux_event(leader) || arch_topdown_sample_read(leader)) { evlist__for_each_entry(evlist, evsel) { if (evsel->leader == leader && evsel != evsel->leader) return evsel; diff --git a/tools/perf/util/topdown.c b/tools/perf/util/topdown.c index a085b3c77c27..1081b20f9891 100644 --- a/tools/perf/util/topdown.c +++ b/tools/perf/util/topdown.c @@ -51,3 +51,8 @@ __weak bool arch_topdown_check_group(bool *warn) __weak void arch_topdown_group_warn(void) { } + +__weak bool arch_topdown_sample_read(struct evsel *leader __maybe_unused) +{ + return false; +} diff --git a/tools/perf/util/topdown.h b/tools/perf/util/topdown.h index e3d70e95f4f1..2f0d0b887639 100644 --- a/tools/perf/util/topdown.h +++ b/tools/perf/util/topdown.h @@ -1,9 +1,11 @@ /* SPDX-License-Identifier: GPL-2.0 */ #ifndef TOPDOWN_H #define TOPDOWN_H 1 +#include "evsel.h" bool arch_topdown_check_group(bool *warn); void arch_topdown_group_warn(void); +bool arch_topdown_sample_read(struct evsel *leader); int topdown_filter_events(const char **attr, char **str, bool use_group); -- 2.17.1
