bw_report is only needed for selecting the correct value from the
values IMC measured. It is a member in the resctrl_val_param struct and
is always set to "reads". The value is then checked in resctrl_val()
using validate_bw_report_request() that besides validating the input,
assumes it can mutate the string which is questionable programming
practice.

Simplify handling bw_report:

- Convert validate_bw_report_request() into get_bw_report_type() that
  inputs and returns const char *. Use NULL to indicate error.

- Validate the report types inside measure_mem_bw(), not in
  resctrl_val().

- As resctrl_val() no longer needs bw_report for anything, it can just
  be passed to measure_mem_bw() by the ->measure() hooks.

Signed-off-by: Ilpo Järvinen <ilpo.jarvi...@linux.intel.com>
---

v2:
- Rebased on top of next to resolve conflict in resctrl.h
---
 tools/testing/selftests/resctrl/mba_test.c    |  3 +--
 tools/testing/selftests/resctrl/mbm_test.c    |  3 +--
 tools/testing/selftests/resctrl/resctrl.h     |  7 +++----
 tools/testing/selftests/resctrl/resctrl_val.c | 19 +++++++++----------
 tools/testing/selftests/resctrl/resctrlfs.c   | 13 ++++++-------
 5 files changed, 20 insertions(+), 25 deletions(-)

diff --git a/tools/testing/selftests/resctrl/mba_test.c 
b/tools/testing/selftests/resctrl/mba_test.c
index 22c1f5e43352..89ad7f2cdd65 100644
--- a/tools/testing/selftests/resctrl/mba_test.c
+++ b/tools/testing/selftests/resctrl/mba_test.c
@@ -75,7 +75,7 @@ static int mba_setup(const struct resctrl_test *test,
 static int mba_measure(const struct user_params *uparams,
                       struct resctrl_val_param *param, pid_t bm_pid)
 {
-       return measure_mem_bw(uparams, param, bm_pid, mbm_total_path);
+       return measure_mem_bw(uparams, param, bm_pid, mbm_total_path, "reads");
 }
 
 static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
@@ -176,7 +176,6 @@ static int mba_run_test(const struct resctrl_test *test, 
const struct user_param
                .ctrlgrp        = "c1",
                .mongrp         = "m1",
                .filename       = RESULT_FILE_NAME,
-               .bw_report      = "reads",
                .init           = set_mba_path,
                .setup          = mba_setup,
                .measure        = mba_measure,
diff --git a/tools/testing/selftests/resctrl/mbm_test.c 
b/tools/testing/selftests/resctrl/mbm_test.c
index ffbfcecf9bd6..c8c9aba81db8 100644
--- a/tools/testing/selftests/resctrl/mbm_test.c
+++ b/tools/testing/selftests/resctrl/mbm_test.c
@@ -129,7 +129,7 @@ static int mbm_setup(const struct resctrl_test *test,
 static int mbm_measure(const struct user_params *uparams,
                       struct resctrl_val_param *param, pid_t bm_pid)
 {
-       return measure_mem_bw(uparams, param, bm_pid, mbm_total_path);
+       return measure_mem_bw(uparams, param, bm_pid, mbm_total_path, "reads");
 }
 
 void mbm_test_cleanup(void)
@@ -144,7 +144,6 @@ static int mbm_run_test(const struct resctrl_test *test, 
const struct user_param
                .ctrlgrp        = "c1",
                .mongrp         = "m1",
                .filename       = RESULT_FILE_NAME,
-               .bw_report      = "reads",
                .init           = set_mbm_path,
                .setup          = mbm_setup,
                .measure        = mbm_measure,
diff --git a/tools/testing/selftests/resctrl/resctrl.h 
b/tools/testing/selftests/resctrl/resctrl.h
index d9c6443a8524..0931c5c09c4f 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -83,7 +83,6 @@ struct resctrl_test {
  * @ctrlgrp:           Name of the control monitor group (con_mon grp)
  * @mongrp:            Name of the monitor group (mon grp)
  * @filename:          Name of file to which the o/p should be written
- * @bw_report:         Bandwidth report type (reads vs writes)
  * @init:              Callback function to initialize test environment
  * @setup:             Callback function to setup per test run environment
  * @measure:           Callback that performs the measurement (a single test)
@@ -93,7 +92,6 @@ struct resctrl_val_param {
        char            ctrlgrp[64];
        char            mongrp[64];
        char            filename[64];
-       char            *bw_report;
        unsigned long   mask;
        int             num_of_runs;
        int             (*init)(const struct resctrl_val_param *param,
@@ -133,7 +131,7 @@ int filter_dmesg(void);
 int get_domain_id(const char *resource, int cpu_no, int *domain_id);
 int mount_resctrlfs(void);
 int umount_resctrlfs(void);
-int validate_bw_report_request(char *bw_report);
+const char *get_bw_report_type(const char *bw_report);
 bool resctrl_resource_exists(const char *resource);
 bool resctrl_mon_feature_exists(const char *resource, const char *feature);
 bool resource_info_file_exists(const char *resource, const char *file);
@@ -153,7 +151,8 @@ int run_fill_buf(size_t buf_size, int memflush, int op, 
bool once);
 int initialize_mem_bw_imc(void);
 int measure_mem_bw(const struct user_params *uparams,
                   struct resctrl_val_param *param,
-                  pid_t bm_pid, const char *mbm_total_path);
+                  pid_t bm_pid, const char *mbm_total_path,
+                  const char *bw_report);
 int resctrl_val(const struct resctrl_test *test,
                const struct user_params *uparams,
                const char * const *benchmark_cmd,
diff --git a/tools/testing/selftests/resctrl/resctrl_val.c 
b/tools/testing/selftests/resctrl/resctrl_val.c
index 1a96298592ed..2f166a5c0c9b 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -320,7 +320,7 @@ static void do_imc_mem_bw_test(void)
  *
  * Return: = 0 on success. < 0 on failure.
  */
-static int get_mem_bw_imc(char *bw_report, float *bw_imc)
+static int get_mem_bw_imc(const char *bw_report, float *bw_imc)
 {
        float reads, writes, of_mul_read, of_mul_write;
        int imc, j;
@@ -517,15 +517,21 @@ static int print_results_bw(char *filename, pid_t bm_pid, 
float bw_imc,
  * @param:             parameters passed to resctrl_val()
  * @bm_pid:            PID that runs the benchmark
  * @mbm_total_path:    Resctrl FS monitoring file to read mem BW from
+ * @bw_report:         Bandwidth report type (reads, writes)
  */
 int measure_mem_bw(const struct user_params *uparams,
                   struct resctrl_val_param *param,
-                  pid_t bm_pid, const char *mbm_total_path)
+                  pid_t bm_pid, const char *mbm_total_path,
+                  const char *bw_report)
 {
        unsigned long bw_resc, bw_resc_start, bw_resc_end;
        float bw_imc;
        int ret;
 
+       bw_report = get_bw_report_type(bw_report);
+       if (!bw_report)
+               return -1;
+
        /*
         * Measure memory bandwidth from resctrl and from
         * another source which is perf imc value or could
@@ -547,7 +553,7 @@ int measure_mem_bw(const struct user_params *uparams,
        if (ret < 0)
                return ret;
 
-       ret = get_mem_bw_imc(param->bw_report, &bw_imc);
+       ret = get_mem_bw_imc(bw_report, &bw_imc);
        if (ret < 0)
                return ret;
 
@@ -642,13 +648,6 @@ int resctrl_val(const struct resctrl_test *test,
                return ret;
        }
 
-       if (!strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR)) ||
-           !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) {
-               ret = validate_bw_report_request(param->bw_report);
-               if (ret)
-                       return ret;
-       }
-
        /*
         * If benchmark wasn't successfully started by child, then child should
         * kill parent, so save parent's pid
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c 
b/tools/testing/selftests/resctrl/resctrlfs.c
index 1cade75176eb..5f113b813253 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -837,22 +837,21 @@ int filter_dmesg(void)
        return 0;
 }
 
-int validate_bw_report_request(char *bw_report)
+const char *get_bw_report_type(const char *bw_report)
 {
        if (strcmp(bw_report, "reads") == 0)
-               return 0;
+               return bw_report;
        if (strcmp(bw_report, "writes") == 0)
-               return 0;
+               return bw_report;
        if (strcmp(bw_report, "nt-writes") == 0) {
-               strcpy(bw_report, "writes");
-               return 0;
+               return "writes";
        }
        if (strcmp(bw_report, "total") == 0)
-               return 0;
+               return bw_report;
 
        fprintf(stderr, "Requested iMC B/W report type unavailable\n");
 
-       return -1;
+       return NULL;
 }
 
 int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
-- 
2.39.2


Reply via email to