Cache Monitoring Technology (CMT) works by measuring how much data in L3 cache is occupied by a given process identified by its Resource Monitoring ID (RMID).
On systems with Sub-Numa Clusters (SNC) enabled, a process can occupy not only the cache that belongs to its own NUMA node but also pieces of other NUMA nodes' caches that lie on the same socket.
A simple correction to make the CMT selftest NUMA-aware is to sum values reported by all nodes on the same socket for a given RMID.
Reported-by: "Shaopeng Tan (Fujitsu)" tan.shaopeng@fujitsu.com Closes: https://lore.kernel.org/all/TYAPR01MB6330B9B17686EF426D2C3F308B25A@TYAPR01MB... Signed-off-by: Maciej Wieczor-Retman maciej.wieczor-retman@intel.com --- tools/testing/selftests/resctrl/cache.c | 17 +++++++++++------ tools/testing/selftests/resctrl/resctrl.h | 4 +++- tools/testing/selftests/resctrl/resctrl_val.c | 9 ++++++--- 3 files changed, 20 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c index 1b339d6bbff1..dab81920033b 100644 --- a/tools/testing/selftests/resctrl/cache.c +++ b/tools/testing/selftests/resctrl/cache.c @@ -161,16 +161,21 @@ int perf_event_measure(int pe_fd, struct perf_event_read *pe_read, * * Return: =0 on success. <0 on failure. */ -int measure_llc_resctrl(const char *filename, int bm_pid) +int measure_llc_resctrl(const char *filename, int bm_pid, const char *ctrlgrp, + const char *mongrp, int res_id) { - unsigned long llc_occu_resc = 0; + unsigned long sum = 0, llc_occu_resc = 0; int ret;
- ret = get_llc_occu_resctrl(&llc_occu_resc); - if (ret < 0) - return ret; + for (int i = 0 ; i < snc_ways() ; i++) { + set_cmt_path(ctrlgrp, mongrp, res_id + i); + ret = get_llc_occu_resctrl(&llc_occu_resc); + if (ret < 0) + return ret; + sum += llc_occu_resc; + }
- return print_results_cache(filename, bm_pid, llc_occu_resc); + return print_results_cache(filename, bm_pid, sum); }
/* diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h index 41811e87f81c..178fb2eab13a 100644 --- a/tools/testing/selftests/resctrl/resctrl.h +++ b/tools/testing/selftests/resctrl/resctrl.h @@ -133,6 +133,7 @@ extern pid_t bm_pid, ppid; extern char llc_occup_path[1024];
int snc_ways(void); +void set_cmt_path(const char *ctrlgrp, const char *mongrp, char sock_num); int get_vendor(void); bool check_resctrlfs_support(void); int filter_dmesg(void); @@ -182,7 +183,8 @@ int perf_open(struct perf_event_attr *pea, pid_t pid, int cpu_no); int perf_event_reset_enable(int pe_fd); int perf_event_measure(int pe_fd, struct perf_event_read *pe_read, const char *filename, int bm_pid); -int measure_llc_resctrl(const char *filename, int bm_pid); +int measure_llc_resctrl(const char *filename, int bm_pid, const char *ctrlgrp, + const char *mongrp, int res_id); void show_cache_info(int no_of_bits, __u64 avg_llc_val, size_t cache_span, bool lines);
/* diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c index 5a49f07a6c85..e75e3923ebe2 100644 --- a/tools/testing/selftests/resctrl/resctrl_val.c +++ b/tools/testing/selftests/resctrl/resctrl_val.c @@ -557,7 +557,7 @@ static int print_results_bw(char *filename, int bm_pid, float bw_imc, return 0; }
-static void set_cmt_path(const char *ctrlgrp, const char *mongrp, char sock_num) +void set_cmt_path(const char *ctrlgrp, const char *mongrp, char sock_num) { if (strlen(ctrlgrp) && strlen(mongrp)) sprintf(llc_occup_path, CON_MON_LCC_OCCUP_PATH, RESCTRL_PATH, @@ -698,8 +698,8 @@ int resctrl_val(const struct resctrl_test *test, { char *resctrl_val = param->resctrl_val; unsigned long bw_resc_start = 0; + int res_id, ret = 0, pipefd[2]; struct sigaction sigact; - int ret = 0, pipefd[2]; char pipe_message = 0; union sigval value;
@@ -828,6 +828,8 @@ int resctrl_val(const struct resctrl_test *test, sleep(1);
/* Test runs until the callback setup() tells the test to stop. */ + get_domain_id("L3", uparams->cpu, &res_id); + res_id *= snc_ways(); while (1) { ret = param->setup(test, uparams, param); if (ret == END_OF_TESTS) { @@ -844,7 +846,8 @@ int resctrl_val(const struct resctrl_test *test, break; } else if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) { sleep(1); - ret = measure_llc_resctrl(param->filename, bm_pid); + ret = measure_llc_resctrl(param->filename, bm_pid, param->ctrlgrp, + param->mongrp, res_id); if (ret) break; }