RE: [PATCH v2 15/24] selftests/resctrl: Refactor get_cbm_mask()

On Wed, 31 May 2023, Shaopeng Tan (Fujitsu) wrote:

Hi Ilpo,

...

Callers of get_cbm_mask() are required to pass a string into which the CBM bit mask is read into. Neither CAT nor CMT tests need the mask as string but just convert it into an unsigned long value.

The bit mask reader can only read .../cbm_mask files.

Generalize the bit mask reading function into get_bit_mask() such that it can be used to handle other files besides the .../cbm_mask and handle the unsigned long conversion within within get_bit_mask() using fscanf(). Alter get_cbm_mask() to construct the filename for get_bit_mask().

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/cat_test.c | 5 +-- tools/testing/selftests/resctrl/cmt_test.c | 5 +-- tools/testing/selftests/resctrl/resctrl.h | 2 +- tools/testing/selftests/resctrl/resctrlfs.c | 50 +++++++++++++++------ 4 files changed, 40 insertions(+), 22 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c index a998e6397518..9bf5d05d9e74 100644 --- a/tools/testing/selftests/resctrl/cat_test.c +++ b/tools/testing/selftests/resctrl/cat_test.c @@ -18,7 +18,6 @@ #define MAX_DIFF 1000000

static int count_of_bits; -static char cbm_mask[256]; static unsigned long long_mask; static unsigned long cache_size;

@@ -101,12 +100,10 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type) cache_size = 0;

/* Get default cbm mask for L3/L2 cache */

• ret = get_cbm_mask(cache_type, cbm_mask);

• ret = get_cbm_mask(cache_type, &long_mask); if (ret) return ret;

• long_mask = strtoul(cbm_mask, NULL, 16);
• /* Get L3/L2 cache size */ ret = get_cache_size(cpu_no, cache_type, &cache_size); if (ret)

diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c index 2d434c03cbba..ae54bbabbd91 100644 --- a/tools/testing/selftests/resctrl/cmt_test.c +++ b/tools/testing/selftests/resctrl/cmt_test.c @@ -17,7 +17,6 @@ #define MAX_DIFF_PERCENT 15

static int count_of_bits; -static char cbm_mask[256]; static unsigned long long_mask; static unsigned long cache_size;

@@ -82,12 +81,10 @@ int cmt_resctrl_val(int cpu_no, int n, char **benchmark_cmd) if (!validate_resctrl_feature_request(CMT_STR)) return -1;

• ret = get_cbm_mask("L3", cbm_mask);

• ret = get_cbm_mask("L3", &long_mask); if (ret) return ret;

• long_mask = strtoul(cbm_mask, NULL, 16);
• ret = get_cache_size(cpu_no, "L3", &cache_size); if (ret) return ret;

diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h index ba36eb5fdf0d..bcc95faa5b4e 100644 --- a/tools/testing/selftests/resctrl/resctrl.h +++ b/tools/testing/selftests/resctrl/resctrl.h @@ -106,7 +106,7 @@ void tests_cleanup(void); void mbm_test_cleanup(void); int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd); void mba_test_cleanup(void); -int get_cbm_mask(char *cache_type, char *cbm_mask); +int get_cbm_mask(char *cache_type, unsigned long *mask); int get_cache_size(int cpu_no, char *cache_type, unsigned long *cache_size); void ctrlc_handler(int signum, siginfo_t *info, void *ptr); int signal_handler_register(void); diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c index 7fef9068d7fd..f01ecfa64063 100644 --- a/tools/testing/selftests/resctrl/resctrlfs.c +++ b/tools/testing/selftests/resctrl/resctrlfs.c @@ -186,30 +186,29 @@ int get_cache_size(int cpu_no, char *cache_type, unsigned long *cache_size) #define CORE_SIBLINGS_PATH "/sys/bus/cpu/devices/cpu"

/*

• • get_cbm_mask - Get cbm mask for given cache
• • @cache_type: Cache level L2/L3
• • @cbm_mask: cbm_mask returned as a string

• • get_bit_mask - Get bit mask from given file
• • @filename: File containing the mask
• • @mask: The bit mask returned as unsigned long
  • Return: = 0 on success, < 0 on failure.
  */

-int get_cbm_mask(char *cache_type, char *cbm_mask) +static int get_bit_mask(char *filename, unsigned long *mask) {

• char cbm_mask_path[1024]; FILE *fp;

• if (!cbm_mask)

• if (!filename || !mask) return -1;

• sprintf(cbm_mask_path, "%s/%s/cbm_mask", INFO_PATH,

cache_type);

• fp = fopen(cbm_mask_path, "r");

• fp = fopen(filename, "r"); if (!fp) {

• perror("Failed to open cache level");
  

• fprintf(stderr, "Failed to open bit mask file '%s': %s\n",
  

• 	filename, strerror(errno));
  

  return -1; }

• if (fscanf(fp, "%s", cbm_mask) <= 0) {

• perror("Could not get max cbm_mask");
  

• if (fscanf(fp, "%lx", mask) <= 0) {

• fprintf(stderr, "Could not read bit mask file '%s': %s\n",
  

• 	filename, strerror(errno));
  

  fclose(fp);

  return -1;

@@ -219,6 +218,31 @@ int get_cbm_mask(char *cache_type, char *cbm_mask) return 0; }

+/*

• • get_cbm_bits - Get number of bits in cbm mask

Is it get_cbm_mask?

Sure, thanks for noticing this. While correcting it, I also improved the description to match what the function now does.