[PATCH v2 4/6] perf amd ibs: Add Load Latency bits in raw dump
From: Ravi Bangoria
Date: Wed Dec 18 2024 - 07:19:52 EST
IBS OP PMU on Zen5 supports Load Latency filtering. Decode and dump Load
Latency filtering related bits into perf script raw dump.
Also add oneliner example in the perf-amd-ibs man page.
Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxx>
---
tools/perf/Documentation/perf-amd-ibs.txt | 9 +++++++++
tools/perf/util/amd-sample-raw.c | 14 ++++++++++++--
2 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/tools/perf/Documentation/perf-amd-ibs.txt b/tools/perf/Documentation/perf-amd-ibs.txt
index 2fd31d9d7b71..55f80beae037 100644
--- a/tools/perf/Documentation/perf-amd-ibs.txt
+++ b/tools/perf/Documentation/perf-amd-ibs.txt
@@ -85,6 +85,15 @@ System-wide profile, uOps event, sampling period: 100000, L3MissOnly (Zen4 onwar
# perf record -e ibs_op/cnt_ctl=1,l3missonly=1/ -c 100000 -a
+System-wide profile, cycles event, sampling period: 100000, LdLat filtering (Zen5
+onward)
+
+ # perf record -e ibs_op/ldlat=128/ -c 100000 -a
+
+ Supported load latency threshold values are 128 to 2048 (both inclusive).
+ Latency value which is a multiple of 128 incurs a little less profiling
+ overhead compared to other values.
+
Per process(upstream v6.2 onward), uOps event, sampling period: 100000
# perf record -e ibs_op/cnt_ctl=1/ -c 100000 -p 1234
diff --git a/tools/perf/util/amd-sample-raw.c b/tools/perf/util/amd-sample-raw.c
index 9d0ce88e90e4..ac34b18ccc0c 100644
--- a/tools/perf/util/amd-sample-raw.c
+++ b/tools/perf/util/amd-sample-raw.c
@@ -19,6 +19,7 @@
static u32 cpu_family, cpu_model, ibs_fetch_type, ibs_op_type;
static bool zen4_ibs_extensions;
+static bool ldlat_cap;
static void pr_ibs_fetch_ctl(union ibs_fetch_ctl reg)
{
@@ -78,14 +79,20 @@ static void pr_ic_ibs_extd_ctl(union ic_ibs_extd_ctl reg)
static void pr_ibs_op_ctl(union ibs_op_ctl reg)
{
char l3_miss_only[sizeof(" L3MissOnly _")] = "";
+ char ldlat[sizeof(" LdLatThrsh __ LdLatEn _")] = "";
if (zen4_ibs_extensions)
snprintf(l3_miss_only, sizeof(l3_miss_only), " L3MissOnly %d", reg.l3_miss_only);
- printf("ibs_op_ctl:\t%016llx MaxCnt %9d%s En %d Val %d CntCtl %d=%s CurCnt %9d\n",
+ if (ldlat_cap) {
+ snprintf(ldlat, sizeof(ldlat), " LdLatThrsh %2d LdLatEn %d",
+ reg.ldlat_thrsh, reg.ldlat_en);
+ }
+
+ printf("ibs_op_ctl:\t%016llx MaxCnt %9d%s En %d Val %d CntCtl %d=%s CurCnt %9d%s\n",
reg.val, ((reg.opmaxcnt_ext << 16) | reg.opmaxcnt) << 4, l3_miss_only,
reg.op_en, reg.op_val, reg.cnt_ctl,
- reg.cnt_ctl ? "uOps" : "cycles", reg.opcurcnt);
+ reg.cnt_ctl ? "uOps" : "cycles", reg.opcurcnt, ldlat);
}
static void pr_ibs_op_data(union ibs_op_data reg)
@@ -331,6 +338,9 @@ bool evlist__has_amd_ibs(struct evlist *evlist)
if (perf_env__find_pmu_cap(env, "ibs_op", "zen4_ibs_extensions"))
zen4_ibs_extensions = 1;
+ if (perf_env__find_pmu_cap(env, "ibs_op", "ldlat"))
+ ldlat_cap = 1;
+
if (ibs_fetch_type || ibs_op_type) {
if (!cpu_family)
parse_cpuid(env);
--
2.43.0