[PATCH v2 08/26] selftests/resctrl: Split measure_cache_vals()

Ilpo Järvinen
2023-11-20T11:14:59Z

measure_cache_vals() does a different thing depending on the test case
that called it:
- For CAT, it measures LLC misses through perf.
- For CMT, it measures LLC occupancy through resctrl.

Split these two functionalities into own functions the CAT and CMT
tests can call directly. Replace passing the struct resctrl_val_param
parameter with the filename because it's more generic and all those
functions need out of resctrl_val.

Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
tools/testing/selftests/resctrl/cache.c | 66 ++++++++++++-------
tools/testing/selftests/resctrl/resctrl.h | 2 +-
tools/testing/selftests/resctrl/resctrl_val.c | 2 +-
3 files changed, 43 insertions(+), 27 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c
index 8aa6d67db978..129d1c293518 100644
--- a/tools/testing/selftests/resctrl/cache.c
+++ b/tools/testing/selftests/resctrl/cache.c
@@ -147,7 +147,7 @@ static int get_llc_occu_resctrl(unsigned long *llc_occupancy)
*
* Return: 0 on success. non-zero on failure.
*/
-static int print_results_cache(char *filename, int bm_pid,
+static int print_results_cache(const char *filename, int bm_pid,
unsigned long llc_value)
{
FILE *fp;
@@ -169,35 +169,51 @@ static int print_results_cache(char *filename, int bm_pid,
return 0;
}

-int measure_cache_vals(struct resctrl_val_param *param, int bm_pid)
+/*
+ * perf_event_measure - Measure perf events
+ * @filename: Filename for writing the results
+ * @bm_pid: PID that runs the benchmark
+ *
+ * Measures perf events (e.g., cache misses) and writes the results into
+ * @filename. @bm_pid is written to the results file along with the measured
+ * value.
+ *
+ * Return: =0 on success. <0 on failure.
+ */
+static int perf_event_measure(const char *filename, int bm_pid)
{
- unsigned long llc_perf_miss = 0, llc_occu_resc = 0, llc_value = 0;
+ unsigned long llc_perf_miss = 0;
int ret;

- /*
- * Measure cache miss from perf.
- */
- if (!strncmp(param->resctrl_val, CAT_STR, sizeof(CAT_STR))) {
- ret = get_llc_perf(&llc_perf_miss);
- if (ret < 0)
- return ret;
- llc_value = llc_perf_miss;
- }
+ ret = get_llc_perf(&llc_perf_miss);
+ if (ret < 0)
+ return ret;

- /*
- * Measure llc occupancy from resctrl.
- */
- if (!strncmp(param->resctrl_val, CMT_STR, sizeof(CMT_STR))) {
- ret = get_llc_occu_resctrl(&llc_occu_resc);
- if (ret < 0)
- return ret;
- llc_value = llc_occu_resc;
- }
- ret = print_results_cache(param->filename, bm_pid, llc_value);
- if (ret)
+ ret = print_results_cache(filename, bm_pid, llc_perf_miss);
+ return ret;
+}
+
+/*
+ * measure_llc_resctrl - Measure resctrl llc value from resctrl
+ * @filename: Filename for writing the results
+ * @bm_pid: PID that runs the benchmark
+ *
+ * Measures llc occupancy from resctrl and writes the results into @filename.
+ * @bm_pid is written to the results file along with the measured value.
+ *
+ * Return: =0 on success. <0 on failure.
+ */
+int measure_llc_resctrl(const char *filename, int bm_pid)
+{
+ unsigned long llc_occu_resc = 0;
+ int ret;
+
+ ret = get_llc_occu_resctrl(&llc_occu_resc);
+ if (ret < 0)
return ret;

- return 0;
+ ret = print_results_cache(filename, bm_pid, llc_occu_resc);
+ return ret;
}

/*
@@ -252,7 +268,7 @@ int cat_val(struct resctrl_val_param *param, size_t span)
}

sleep(1);
- ret = measure_cache_vals(param, bm_pid);
+ ret = perf_event_measure(param->filename, bm_pid);
if (ret)
goto pe_close;
}
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index a911b08fa595..d35e3ba4dfa2 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -114,7 +114,7 @@ int cmt_resctrl_val(int cpu_no, int n, const char * const *benchmark_cmd);
unsigned int count_bits(unsigned long n);
void cmt_test_cleanup(void);
int get_core_sibling(int cpu_no);
-int measure_cache_vals(struct resctrl_val_param *param, int bm_pid);
+int measure_llc_resctrl(const char *filename, int bm_pid);
int show_cache_info(unsigned long sum_llc_val, int no_of_bits,
size_t cache_span, unsigned long max_diff,
unsigned long max_diff_percent, unsigned long num_of_runs,
diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 88789678917b..a07ba336db48 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -830,7 +830,7 @@ int resctrl_val(const char * const *benchmark_cmd, struct resctrl_val_param *par
break;
} else if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) {
sleep(1);
- ret = measure_cache_vals(param, bm_pid);
+ ret = measure_llc_resctrl(param->filename, bm_pid);
if (ret)
break;
}
--
2.30.2