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authorRavi Bangoria <[email protected]>2022-10-06 21:09:43 +0530
committerArnaldo Carvalho de Melo <[email protected]>2022-10-06 16:30:06 -0300
commitf7b58cbdb3ff36eba8622e67eee66c10dd1c9995 (patch)
tree9292d983a625e5331b122cd257cf801deefe6305
parent4173cc055dc92f199a43775775e54dc7fafd37b6 (diff)
perf mem/c2c: Add load store event mappings for AMD
The 'perf mem' and 'perf c2c' tools are wrappers around 'perf record' with mem load/ store events. IBS tagged load/store sample provides most of the information needed for these tools. Wire in the "ibs_op//" event as mem-ldst event for AMD. There are some limitations though: Only load/store micro-ops provide mem/c2c information. Whereas, IBS does not have a way to choose a particular type of micro-op to tag. This results in many non-LS micro-ops being tagged which appear as N/A in the perf report. IBS, being an uncore pmu from kernel point of view[1], does not support per process monitoring. Thus, perf mem/c2c on AMD are currently supported in per-cpu mode only. Example: $ sudo perf mem record -- -c 10000 ^C[ perf record: Woken up 227 times to write data ] [ perf record: Captured and wrote 58.760 MB perf.data (836978 samples) ] $ sudo perf mem report -F mem,sample,snoop Samples: 836K of event 'ibs_op//', Event count (approx.): 8418762 Memory access Samples Snoop N/A 700620 N/A L1 hit 126675 N/A L2 hit 424 N/A L3 hit 664 HitM L3 hit 10 N/A Local RAM hit 2 N/A Remote RAM (1 hop) hit 8558 N/A Remote Cache (1 hop) hit 3 N/A Remote Cache (1 hop) hit 2 HitM Remote Cache (2 hops) hit 10 HitM Remote Cache (2 hops) hit 6 N/A Uncached hit 4 N/A $ [1]: https://lore.kernel.org/lkml/[email protected] Signed-off-by: Ravi Bangoria <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ali Saidi <[email protected]> Cc: Ananth Narayan <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Dave Hansen <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Joe Mario <[email protected]> Cc: Kan Liang <[email protected]> Cc: Kim Phillips <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Sandipan Das <[email protected]> Cc: Santosh Shukla <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
-rw-r--r--tools/perf/Documentation/perf-c2c.txt14
-rw-r--r--tools/perf/Documentation/perf-mem.txt3
-rw-r--r--tools/perf/arch/x86/util/mem-events.c31
3 files changed, 41 insertions, 7 deletions
diff --git a/tools/perf/Documentation/perf-c2c.txt b/tools/perf/Documentation/perf-c2c.txt
index f1f7ae6b08d1..5c5eb2def83e 100644
--- a/tools/perf/Documentation/perf-c2c.txt
+++ b/tools/perf/Documentation/perf-c2c.txt
@@ -19,9 +19,10 @@ C2C stands for Cache To Cache.
The perf c2c tool provides means for Shared Data C2C/HITM analysis. It allows
you to track down the cacheline contentions.
-On x86, the tool is based on load latency and precise store facility events
+On Intel, the tool is based on load latency and precise store facility events
provided by Intel CPUs. On PowerPC, the tool uses random instruction sampling
-with thresholding feature.
+with thresholding feature. On AMD, the tool uses IBS op pmu (due to hardware
+limitations, perf c2c is not supported on Zen3 cpus).
These events provide:
- memory address of the access
@@ -49,7 +50,8 @@ RECORD OPTIONS
-l::
--ldlat::
- Configure mem-loads latency. (x86 only)
+ Configure mem-loads latency. Supported on Intel and Arm64 processors
+ only. Ignored on other archs.
-k::
--all-kernel::
@@ -135,11 +137,15 @@ Following perf record options are configured by default:
-W,-d,--phys-data,--sample-cpu
Unless specified otherwise with '-e' option, following events are monitored by
-default on x86:
+default on Intel:
cpu/mem-loads,ldlat=30/P
cpu/mem-stores/P
+following on AMD:
+
+ ibs_op//
+
and following on PowerPC:
cpu/mem-loads/
diff --git a/tools/perf/Documentation/perf-mem.txt b/tools/perf/Documentation/perf-mem.txt
index 66177511c5c4..005c95580b1e 100644
--- a/tools/perf/Documentation/perf-mem.txt
+++ b/tools/perf/Documentation/perf-mem.txt
@@ -85,7 +85,8 @@ RECORD OPTIONS
Be more verbose (show counter open errors, etc)
--ldlat <n>::
- Specify desired latency for loads event. (x86 only)
+ Specify desired latency for loads event. Supported on Intel and Arm64
+ processors only. Ignored on other archs.
In addition, for report all perf report options are valid, and for record
all perf record options.
diff --git a/tools/perf/arch/x86/util/mem-events.c b/tools/perf/arch/x86/util/mem-events.c
index 5214370ca4e4..f683ac702247 100644
--- a/tools/perf/arch/x86/util/mem-events.c
+++ b/tools/perf/arch/x86/util/mem-events.c
@@ -1,7 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
#include "util/pmu.h"
+#include "util/env.h"
#include "map_symbol.h"
#include "mem-events.h"
+#include "linux/string.h"
static char mem_loads_name[100];
static bool mem_loads_name__init;
@@ -12,18 +14,43 @@ static char mem_stores_name[100];
#define E(t, n, s) { .tag = t, .name = n, .sysfs_name = s }
-static struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX] = {
+static struct perf_mem_event perf_mem_events_intel[PERF_MEM_EVENTS__MAX] = {
E("ldlat-loads", "%s/mem-loads,ldlat=%u/P", "%s/events/mem-loads"),
E("ldlat-stores", "%s/mem-stores/P", "%s/events/mem-stores"),
E(NULL, NULL, NULL),
};
+static struct perf_mem_event perf_mem_events_amd[PERF_MEM_EVENTS__MAX] = {
+ E(NULL, NULL, NULL),
+ E(NULL, NULL, NULL),
+ E("mem-ldst", "ibs_op//", "ibs_op"),
+};
+
+static int perf_mem_is_amd_cpu(void)
+{
+ struct perf_env env = { .total_mem = 0, };
+
+ perf_env__cpuid(&env);
+ if (env.cpuid && strstarts(env.cpuid, "AuthenticAMD"))
+ return 1;
+ return -1;
+}
+
struct perf_mem_event *perf_mem_events__ptr(int i)
{
+ /* 0: Uninitialized, 1: Yes, -1: No */
+ static int is_amd;
+
if (i >= PERF_MEM_EVENTS__MAX)
return NULL;
- return &perf_mem_events[i];
+ if (!is_amd)
+ is_amd = perf_mem_is_amd_cpu();
+
+ if (is_amd == 1)
+ return &perf_mem_events_amd[i];
+
+ return &perf_mem_events_intel[i];
}
bool is_mem_loads_aux_event(struct evsel *leader)