On the Intel Sapphire Rapids server, an auxiliary event has to be
enabled simultaneously with the load latency event to retrieve complete
Memory Info.
Add X86 specific perf_mem_events__name() to handle the auxiliary event.
- Users are only interested in the samples of the mem-loads event.
Sample read the auxiliary event.
- The auxiliary event must be in front of the load latency event in a
group. Assume the second event to sample if the auxiliary event is the
leader.
- Add a weak is_mem_loads_aux_event() to check the auxiliary event for
X86. For other ARCHs, it always return false.
Parse the unique event name, mem-loads-aux, for the auxiliary event.
Committer notes:
According to
61b985e3e775a3a7 ("perf/x86/intel: Add perf core PMU
support for Sapphire Rapids"), ENODATA is only returned by
sys_perf_event_open() when used with these auxiliary events, with this
in evsel__open_strerror():
case ENODATA:
return scnprintf(msg, size, "Cannot collect data source with the load latency event alone. "
"Please add an auxiliary event in front of the load latency event.");
This is Ok at this point in time, but fragile long term, I pointed this
out in the e-mail thread, requesting a follow up patch to check if
ENODATA is really for this specific case.
Fixed up sizeof(MEM_LOADS_AUX_NAME) bug pointed out by Namhyung.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210205152648.GC920417@kernel.org
Link: http://lore.kernel.org/lkml/1612296553-21962-3-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf-y += machine.o
perf-y += event.o
perf-y += evlist.o
+perf-y += mem-events.o
perf-$(CONFIG_DWARF) += dwarf-regs.o
perf-$(CONFIG_BPF_PROLOGUE) += dwarf-regs.o
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+#include "util/pmu.h"
+#include "map_symbol.h"
+#include "mem-events.h"
+
+static char mem_loads_name[100];
+static bool mem_loads_name__init;
+
+#define MEM_LOADS_AUX 0x8203
+#define MEM_LOADS_AUX_NAME "{cpu/mem-loads-aux/,cpu/mem-loads,ldlat=%u/pp}:S"
+
+bool is_mem_loads_aux_event(struct evsel *leader)
+{
+ if (!pmu_have_event("cpu", "mem-loads-aux"))
+ return false;
+
+ return leader->core.attr.config == MEM_LOADS_AUX;
+}
+
+char *perf_mem_events__name(int i)
+{
+ struct perf_mem_event *e = perf_mem_events__ptr(i);
+
+ if (!e)
+ return NULL;
+
+ if (i == PERF_MEM_EVENTS__LOAD) {
+ if (mem_loads_name__init)
+ return mem_loads_name;
+
+ mem_loads_name__init = true;
+
+ if (pmu_have_event("cpu", "mem-loads-aux")) {
+ scnprintf(mem_loads_name, sizeof(mem_loads_name),
+ MEM_LOADS_AUX_NAME, perf_mem_events__loads_ldlat);
+ } else {
+ scnprintf(mem_loads_name, sizeof(mem_loads_name),
+ e->name, perf_mem_events__loads_ldlat);
+ }
+ return mem_loads_name;
+ }
+
+ return (char *)e->name;
+}
if (perf_missing_features.aux_output)
return scnprintf(msg, size, "The 'aux_output' feature is not supported, update the kernel.");
break;
+ case ENODATA:
+ return scnprintf(msg, size, "Cannot collect data source with the load latency event alone. "
+ "Please add an auxiliary event in front of the load latency event.");
default:
break;
}
return (char *)e->name;
}
+__weak bool is_mem_loads_aux_event(struct evsel *leader __maybe_unused)
+{
+ return false;
+}
+
int perf_mem_events__parse(const char *str)
{
char *tok, *saveptr = NULL;
#include <linux/refcount.h>
#include <linux/perf_event.h>
#include "stat.h"
+#include "evsel.h"
struct perf_mem_event {
bool record;
char *perf_mem_events__name(int i);
struct perf_mem_event *perf_mem_events__ptr(int i);
+bool is_mem_loads_aux_event(struct evsel *leader);
void perf_mem_events__list(void);
cycles-ct |
cycles-t |
mem-loads |
+mem-loads-aux |
mem-stores |
topdown-[a-z-]+ |
tx-capacity-[a-z-]+ |
#include "record.h"
#include "../perf-sys.h"
#include "topdown.h"
+#include "map_symbol.h"
+#include "mem-events.h"
/*
* evsel__config_leader_sampling() uses special rules for leader sampling.
{
struct evsel *leader = evsel->leader;
- if (evsel__is_aux_event(leader) || arch_topdown_sample_read(leader)) {
+ if (evsel__is_aux_event(leader) || arch_topdown_sample_read(leader) ||
+ is_mem_loads_aux_event(leader)) {
evlist__for_each_entry(evlist, evsel) {
if (evsel->leader == leader && evsel != evsel->leader)
return evsel;