Reinette reported following compilation issue on Fedora 32, gcc version 10.1.1
/usr/bin/ld: cmt_test.o:<src_dir>/cmt_test.c:19: multiple definition of `cbm_mask'; cat_test.o:<src_dir>/cat_test.c:20: first defined here /usr/bin/ld: resctrlfs.o:<src_dir>/resctrlfs.c:52: multiple definition of `cbm_mask'; cat_test.o:<src_dir>/cat_test.c:20: first defined here
Compiler throws an error because cbm_mask is defined as a global variable in three different .c files, namely resctrlfs.c, cat_test.c and cmt_test.c.
cbm_mask is a global variable that is supposed to hold the capacity bitmask (CBM) value read from resctrl/info directory. This is done by get_cbm_mask() function which then sets the global variable.
To reduce the use of global variables (thereby improving readability and maintainability) change get_cbm_mask() implementation such that it now accepts a reference to a string. Upon success, get_cbm_mask() populates the string with CBM value read from resctrl/info directory and returns 0 and on failure, returns -1.
Please note that this change to get_cbm_mask() fixes the issue reported by Reinette because cbm_mask isn't a global variable anymore.
Fixes: 78941183d1b15 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest") Fixes: 790bf585b0eee ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest") Reported-by: Reinette Chatre reinette.chatre@intel.com Signed-off-by: Fenghua Yu fenghua.yu@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 | 10 +++++----- 4 files changed, 10 insertions(+), 12 deletions(-)
diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c index e518f8f7b4d8..60b31b85b484 100644 --- a/tools/testing/selftests/resctrl/cat_test.c +++ b/tools/testing/selftests/resctrl/cat_test.c @@ -17,8 +17,6 @@ #define MAX_DIFF_PERCENT 4 #define MAX_DIFF 1000000
-char cbm_mask[256]; - /* * Change schemata. Write schemata to specified * con_mon grp, mon_grp in resctrl FS. @@ -120,6 +118,7 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type) { unsigned long l_mask, l_mask_1, long_mask, cache_size; int ret, pipefd[2], sibling_cpu_no, count_of_bits; + char cbm_mask[256]; char pipe_message; pid_t bm_pid;
@@ -130,7 +129,7 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type) return ret;
/* Get default cbm mask for L3/L2 cache */ - ret = get_cbm_mask(cache_type); + ret = get_cbm_mask(cache_type, cbm_mask); if (ret) return ret;
diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c index f0cb441cca9f..0bee3e6480a3 100644 --- a/tools/testing/selftests/resctrl/cmt_test.c +++ b/tools/testing/selftests/resctrl/cmt_test.c @@ -16,8 +16,6 @@ #define MAX_DIFF 2000000 #define MAX_DIFF_PERCENT 15
-char cbm_mask[256]; - static int cmt_setup(int num, ...) { struct resctrl_val_param *p; @@ -112,6 +110,7 @@ int cmt_resctrl_val(int cpu_no, int n, char **benchmark_cmd) { int ret, mum_resctrlfs, count_of_bits; unsigned long long_mask, cache_size; + char cbm_mask[256];
cache_size = 0; mum_resctrlfs = 1; @@ -120,7 +119,7 @@ int cmt_resctrl_val(int cpu_no, int n, char **benchmark_cmd) if (ret) return ret;
- ret = get_cbm_mask("L3"); + ret = get_cbm_mask("L3", cbm_mask); if (ret) return ret;
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h index 65ca24bf3eac..2546435864d0 100644 --- a/tools/testing/selftests/resctrl/resctrl.h +++ b/tools/testing/selftests/resctrl/resctrl.h @@ -96,7 +96,7 @@ 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); +int get_cbm_mask(char *cache_type, char *cbm_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 cat_val(struct resctrl_val_param *param); diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c index 21281fd895b7..a07118e01590 100644 --- a/tools/testing/selftests/resctrl/resctrlfs.c +++ b/tools/testing/selftests/resctrl/resctrlfs.c @@ -49,8 +49,6 @@ static int find_resctrl_mount(char *buffer) return -ENOENT; }
-char cbm_mask[256]; - /* * remount_resctrlfs - Remount resctrl FS at /sys/fs/resctrl * @mum_resctrlfs: Should the resctrl FS be remounted? @@ -208,16 +206,18 @@ int get_cache_size(int cpu_no, char *cache_type, unsigned long *cache_size) /* * get_cbm_mask - Get cbm mask for given cache * @cache_type: Cache level L2/L3 - * - * Mask is stored in cbm_mask which is global variable. + * @cbm_mask: cbm_mask returned as a string * * Return: = 0 on success, < 0 on failure. */ -int get_cbm_mask(char *cache_type) +int get_cbm_mask(char *cache_type, char *cbm_mask) { char cbm_mask_path[1024]; FILE *fp;
+ if (!cbm_mask) + return -1; + sprintf(cbm_mask_path, "%s/%s/cbm_mask", CBM_MASK_PATH, cache_type);
fp = fopen(cbm_mask_path, "r");