[PATCH v3 00/21] Miscellaneous fixes for resctrl selftests

[PATCH v3 00/21] Miscellaneous fixes for resctrl selftests

[Fenghua Yu]

This patch set has several miscellaneous fixes to resctrl selftest tool
that are easily visible to user. V1 had fixes to CAT test and CMT test
but they were dropped in V2 because having them here made the patchset
humongous. So, changes to CAT test and CMT test will be posted in another
patchset.

Change Log:
v3:
Address various comments (commit messages, return value on test failure,
print failure info on test failure etc) from Reinette and Tony.
[v2: https://lore.kernel.org/linux-kselftest/cover.1589835155.git.sai.praneeth.prakhya@intel.com/]

v2:
1. Dropped changes to CAT test and CMT test as they will be posted in a later
   series.
2. Added several other fixes
[v1: https://lore.kernel.org/linux-kselftest/cover.1583657204.git.sai.praneeth.prakhya@intel.com/]

Fenghua Yu (18):
  selftests/resctrl: Rename CQM test as CMT test
  selftests/resctrl: Declare global variables as extern
  selftests/resctrl: Return if resctrl file system is not supported
  selftests/resctrl: Check for resctrl mount point only if resctrl FS is
    supported
  selftests/resctrl: Use resctrl/info for feature detection
  selftests/resctrl: Fix missing options "-n" and "-p"
  selftests/resctrl: Fix MBA/MBM results reporting format
  selftests/resctrl: Abort running tests if not root user
  selftests/resctrl: Enable gcc checks to detect buffer overflows
  selftests/resctrl: Don't hard code value of "no_of_bits" variable
  selftests/resctrl: Modularize resctrl test suite main() function
  selftests/resctrl: Skip the test if requested resctrl feature is not
    supported
  selftests/resctrl: Umount resctrl FS only if mounted
  selftests/resctrl: Unmount resctrl FS after running all tests
  selftests/resctrl: Fix incorrect parsing of iMC counters
  selftests/resctrl: Fix checking for < 0 for unsigned values
  selftests/resctrl: Fix unnecessary usage of global variables
  selftests/resctrl: Don't use global variable for capacity bitmask
    (CBM)

Reinette Chatre (3):
  selftests/resctrl: Fix typo
  selftests/resctrl: Fix typo in help text
  selftests/resctrl: Ensure sibling CPU is not same as original CPU

 tools/testing/selftests/resctrl/Makefile      |   2 +-
 tools/testing/selftests/resctrl/README        |   4 +-
 tools/testing/selftests/resctrl/cache.c       |   4 +-
 tools/testing/selftests/resctrl/cat_test.c    |  20 +--
 .../resctrl/{cqm_test.c => cmt_test.c}        |  34 ++--
 tools/testing/selftests/resctrl/mba_test.c    |  23 ++-
 tools/testing/selftests/resctrl/mbm_test.c    |  16 +-
 tools/testing/selftests/resctrl/resctrl.h     |  20 ++-
 .../testing/selftests/resctrl/resctrl_tests.c | 156 ++++++++++++------
 tools/testing/selftests/resctrl/resctrl_val.c |  75 ++++++---
 tools/testing/selftests/resctrl/resctrlfs.c   |  79 ++++++---
 11 files changed, 272 insertions(+), 161 deletions(-)
 rename tools/testing/selftests/resctrl/{cqm_test.c => cmt_test.c} (85%)

-- 
2.29.0

[PATCH v3 01/21] selftests/resctrl: Rename CQM test as CMT test

[Fenghua Yu]

CMT (Cache Monitoring Technology) [1] is a H/W feature that reports cache
occupancy of a process. resctrl selftest suite has a unit test to test CMT
for LLC but the test is named as CQM (Cache Quality Monitoring).
Furthermore, the unit test source file is named as cqm_test.c and several
functions, variables, comments, preprocessors and statements widely use
"cqm" as either suffix or prefix. This rampant misusage of CQM for CMT
might confuse someone who is newly looking at resctrl selftests because
this feature is named CMT in the Intel Software Developer's Manual.

Hence, rename all the occurrences (unit test source file name, functions,
variables, comments and preprocessors) of cqm with cmt.

[1] Please see Intel SDM, Volume 3, chapter 17 and section 18 for more
    information on CMT.

Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/README        |  4 +--
 tools/testing/selftests/resctrl/cache.c       |  4 +--
 .../resctrl/{cqm_test.c => cmt_test.c}        | 20 +++++++-------
 tools/testing/selftests/resctrl/resctrl.h     |  4 +--
 .../testing/selftests/resctrl/resctrl_tests.c | 26 +++++++++----------
 tools/testing/selftests/resctrl/resctrl_val.c | 12 ++++-----
 tools/testing/selftests/resctrl/resctrlfs.c   | 10 +++----
 7 files changed, 40 insertions(+), 40 deletions(-)
 rename tools/testing/selftests/resctrl/{cqm_test.c => cmt_test.c} (89%)

diff --git a/tools/testing/selftests/resctrl/README b/tools/testing/selftests/resctrl/README
index 6e5a0ffa18e8..4b36b25b6ac0 100644
--- a/tools/testing/selftests/resctrl/README
+++ b/tools/testing/selftests/resctrl/README
@@ -46,8 +46,8 @@ ARGUMENTS
 Parameter '-h' shows usage information.
 
 usage: resctrl_tests [-h] [-b "benchmark_cmd [options]"] [-t test list] [-n no_of_bits]
-        -b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CQM default benchmark is builtin fill_buf
-        -t test list: run tests specified in the test list, e.g. -t mbm, mba, cqm, cat
+        -b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CMT default benchmark is builtin fill_buf
+        -t test list: run tests specified in the test list, e.g. -t mbm, mba, cmt, cat
         -n no_of_bits: run cache tests using specified no of bits in cache bit mask
         -p cpu_no: specify CPU number to run the test. 1 is default
         -h: help
diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c
index 38dbf4962e33..4d73edd81293 100644
--- a/tools/testing/selftests/resctrl/cache.c
+++ b/tools/testing/selftests/resctrl/cache.c
@@ -111,7 +111,7 @@ static int get_llc_perf(unsigned long *llc_perf_miss)
 
 /*
  * Get LLC Occupancy as reported by RESCTRL FS
- * For CQM,
+ * For CMT,
  * 1. If con_mon grp and mon grp given, then read from mon grp in
  * con_mon grp
  * 2. If only con_mon grp given, then read from con_mon grp
@@ -192,7 +192,7 @@ int measure_cache_vals(struct resctrl_val_param *param, int bm_pid)
 	/*
 	 * Measure llc occupancy from resctrl.
 	 */
-	if (!strcmp(param->resctrl_val, "cqm")) {
+	if (!strcmp(param->resctrl_val, "cmt")) {
 		ret = get_llc_occu_resctrl(&llc_occu_resc);
 		if (ret < 0)
 			return ret;
diff --git a/tools/testing/selftests/resctrl/cqm_test.c b/tools/testing/selftests/resctrl/cmt_test.c
similarity index 89%
rename from tools/testing/selftests/resctrl/cqm_test.c
rename to tools/testing/selftests/resctrl/cmt_test.c
index c8756152bd61..13b01e010238 100644
--- a/tools/testing/selftests/resctrl/cqm_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Cache Monitoring Technology (CQM) test
+ * Cache Monitoring Technology (CMT) test
  *
  * Copyright (C) 2018 Intel Corporation
  *
@@ -11,7 +11,7 @@
 #include "resctrl.h"
 #include <unistd.h>
 
-#define RESULT_FILE_NAME	"result_cqm"
+#define RESULT_FILE_NAME	"result_cmt"
 #define NUM_OF_RUNS		5
 #define MAX_DIFF		2000000
 #define MAX_DIFF_PERCENT	15
@@ -21,7 +21,7 @@ char cbm_mask[256];
 unsigned long long_mask;
 unsigned long cache_size;
 
-static int cqm_setup(int num, ...)
+static int cmt_setup(int num, ...)
 {
 	struct resctrl_val_param *p;
 	va_list param;
@@ -58,7 +58,7 @@ static void show_cache_info(unsigned long sum_llc_occu_resc, int no_of_bits,
 	else
 		res = false;
 
-	printf("%sok CQM: diff within %d, %d\%%\n", res ? "" : "not",
+	printf("%sok CMT: diff within %d, %d\%%\n", res ? "" : "not",
 	       MAX_DIFF, (int)MAX_DIFF_PERCENT);
 
 	printf("# diff: %ld\n", avg_diff);
@@ -106,12 +106,12 @@ static int check_results(struct resctrl_val_param *param, int no_of_bits)
 	return 0;
 }
 
-void cqm_test_cleanup(void)
+void cmt_test_cleanup(void)
 {
 	remove(RESULT_FILE_NAME);
 }
 
-int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
+int cmt_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
 {
 	int ret, mum_resctrlfs;
 
@@ -122,7 +122,7 @@ int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
 	if (ret)
 		return ret;
 
-	if (!validate_resctrl_feature_request("cqm"))
+	if (!validate_resctrl_feature_request("cmt"))
 		return -1;
 
 	ret = get_cbm_mask("L3");
@@ -145,7 +145,7 @@ int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
 	}
 
 	struct resctrl_val_param param = {
-		.resctrl_val	= "cqm",
+		.resctrl_val	= "cmt",
 		.ctrlgrp	= "c1",
 		.mongrp		= "m1",
 		.cpu_no		= cpu_no,
@@ -154,7 +154,7 @@ int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
 		.mask		= ~(long_mask << n) & long_mask,
 		.span		= cache_size * n / count_of_bits,
 		.num_of_runs	= 0,
-		.setup		= cqm_setup,
+		.setup		= cmt_setup,
 	};
 
 	if (strcmp(benchmark_cmd[0], "fill_buf") == 0)
@@ -170,7 +170,7 @@ int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
 	if (ret)
 		return ret;
 
-	cqm_test_cleanup();
+	cmt_test_cleanup();
 
 	return 0;
 }
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index 39bf59c6b9c5..68522b19b235 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -98,9 +98,9 @@ void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
 int cat_val(struct resctrl_val_param *param);
 void cat_test_cleanup(void);
 int cat_perf_miss_val(int cpu_no, int no_of_bits, char *cache_type);
-int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd);
+int cmt_resctrl_val(int cpu_no, int n, char **benchmark_cmd);
 unsigned int count_bits(unsigned long n);
-void cqm_test_cleanup(void);
+void cmt_test_cleanup(void);
 int get_core_sibling(int cpu_no);
 int measure_cache_vals(struct resctrl_val_param *param, int bm_pid);
 
diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index 425cc85ac883..35a91cab1b88 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -37,10 +37,10 @@ void detect_amd(void)
 static void cmd_help(void)
 {
 	printf("usage: resctrl_tests [-h] [-b \"benchmark_cmd [options]\"] [-t test list] [-n no_of_bits]\n");
-	printf("\t-b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CQM");
+	printf("\t-b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CMT");
 	printf("\t default benchmark is builtin fill_buf\n");
 	printf("\t-t test list: run tests specified in the test list, ");
-	printf("e.g. -t mbm, mba, cqm, cat\n");
+	printf("e.g. -t mbm, mba, cmt, cat\n");
 	printf("\t-n no_of_bits: run cache tests using specified no of bits in cache bit mask\n");
 	printf("\t-p cpu_no: specify CPU number to run the test. 1 is default\n");
 	printf("\t-h: help\n");
@@ -50,13 +50,13 @@ void tests_cleanup(void)
 {
 	mbm_test_cleanup();
 	mba_test_cleanup();
-	cqm_test_cleanup();
+	cmt_test_cleanup();
 	cat_test_cleanup();
 }
 
 int main(int argc, char **argv)
 {
-	bool has_ben = false, mbm_test = true, mba_test = true, cqm_test = true;
+	bool has_ben = false, mbm_test = true, mba_test = true, cmt_test = true;
 	int res, c, cpu_no = 1, span = 250, argc_new = argc, i, no_of_bits = 5;
 	char *benchmark_cmd[BENCHMARK_ARGS], bw_report[64], bm_type[64];
 	char benchmark_cmd_area[BENCHMARK_ARGS][BENCHMARK_ARG_SIZE];
@@ -82,15 +82,15 @@ int main(int argc, char **argv)
 
 			mbm_test = false;
 			mba_test = false;
-			cqm_test = false;
+			cmt_test = false;
 			cat_test = false;
 			while (token) {
 				if (!strcmp(token, "mbm")) {
 					mbm_test = true;
 				} else if (!strcmp(token, "mba")) {
 					mba_test = true;
-				} else if (!strcmp(token, "cqm")) {
-					cqm_test = true;
+				} else if (!strcmp(token, "cmt")) {
+					cmt_test = true;
 				} else if (!strcmp(token, "cat")) {
 					cat_test = true;
 				} else {
@@ -178,13 +178,13 @@ int main(int argc, char **argv)
 		tests_run++;
 	}
 
-	if (cqm_test) {
-		printf("# Starting CQM test ...\n");
+	if (cmt_test) {
+		printf("# Starting CMT test ...\n");
 		if (!has_ben)
-			sprintf(benchmark_cmd[5], "%s", "cqm");
-		res = cqm_resctrl_val(cpu_no, no_of_bits, benchmark_cmd);
-		printf("%sok CQM: test\n", res ? "not " : "");
-		cqm_test_cleanup();
+			sprintf(benchmark_cmd[5], "%s", "cmt");
+		res = cmt_resctrl_val(cpu_no, no_of_bits, benchmark_cmd);
+		printf("%sok CMT: test\n", res ? "not " : "");
+		cmt_test_cleanup();
 		tests_run++;
 	}
 
diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 520fea3606d1..270cd95e0026 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -492,7 +492,7 @@ static int print_results_bw(char *filename,  int bm_pid, float bw_imc,
 	return 0;
 }
 
-static void set_cqm_path(const char *ctrlgrp, const char *mongrp, char sock_num)
+static 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,
@@ -512,7 +512,7 @@ static void set_cqm_path(const char *ctrlgrp, const char *mongrp, char sock_num)
  * @ctrlgrp:			Name of the control monitor group (con_mon grp)
  * @mongrp:			Name of the monitor group (mon grp)
  * @cpu_no:			CPU number that the benchmark PID is binded to
- * @resctrl_val:		Resctrl feature (Eg: cat, cqm.. etc)
+ * @resctrl_val:		Resctrl feature (Eg: cat, cmt.. etc)
  */
 static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp,
 					int cpu_no, char *resctrl_val)
@@ -524,8 +524,8 @@ static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp,
 		return;
 	}
 
-	if (strcmp(resctrl_val, "cqm") == 0)
-		set_cqm_path(ctrlgrp, mongrp, resource_id);
+	if (strcmp(resctrl_val, "cmt") == 0)
+		set_cmt_path(ctrlgrp, mongrp, resource_id);
 }
 
 static int
@@ -682,7 +682,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
 
 		initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp,
 					  param->cpu_no, resctrl_val);
-	} else if (strcmp(resctrl_val, "cqm") == 0)
+	} else if (strcmp(resctrl_val, "cmt") == 0)
 		initialize_llc_occu_resctrl(param->ctrlgrp, param->mongrp,
 					    param->cpu_no, resctrl_val);
 
@@ -721,7 +721,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
 			ret = measure_vals(param, &bw_resc_start);
 			if (ret)
 				break;
-		} else if (strcmp(resctrl_val, "cqm") == 0) {
+		} else if (strcmp(resctrl_val, "cmt") == 0) {
 			ret = param->setup(1, param);
 			if (ret) {
 				ret = 0;
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 19c0ec4045a4..727e667e2cc9 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -334,7 +334,7 @@ void run_benchmark(int signum, siginfo_t *info, void *ucontext)
 		operation = atoi(benchmark_cmd[4]);
 		sprintf(resctrl_val, "%s", benchmark_cmd[5]);
 
-		if (strcmp(resctrl_val, "cqm") != 0)
+		if (strcmp(resctrl_val, "cmt") != 0)
 			buffer_span = span * MB;
 		else
 			buffer_span = span;
@@ -458,8 +458,8 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
 	if (ret)
 		goto out;
 
-	/* Create mon grp and write pid into it for "mbm" and "cqm" test */
-	if ((strcmp(resctrl_val, "cqm") == 0) ||
+	/* Create mon grp and write pid into it for "mbm" and "cmt" test */
+	if ((strcmp(resctrl_val, "cmt") == 0) ||
 	    (strcmp(resctrl_val, "mbm") == 0)) {
 		if (strlen(mongrp)) {
 			sprintf(monitorgroup_p, "%s/mon_groups", controlgroup);
@@ -507,7 +507,7 @@ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
 
 	if ((strcmp(resctrl_val, "mba") != 0) &&
 	    (strcmp(resctrl_val, "cat") != 0) &&
-	    (strcmp(resctrl_val, "cqm") != 0))
+	    (strcmp(resctrl_val, "cmt") != 0))
 		return -ENOENT;
 
 	if (!schemata) {
@@ -528,7 +528,7 @@ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
 	else
 		sprintf(controlgroup, "%s/schemata", RESCTRL_PATH);
 
-	if (!strcmp(resctrl_val, "cat") || !strcmp(resctrl_val, "cqm"))
+	if (!strcmp(resctrl_val, "cat") || !strcmp(resctrl_val, "cmt"))
 		sprintf(schema, "%s%d%c%s", "L3:", resource_id, '=', schemata);
 	if (strcmp(resctrl_val, "mba") == 0)
 		sprintf(schema, "%s%d%c%s", "MB:", resource_id, '=', schemata);
-- 
2.29.0

Re: [PATCH v3 01/21] selftests/resctrl: Rename CQM test as CMT test

[Shuah Khan]

On 10/20/20 5:51 PM, Fenghua Yu wrote:
> CMT (Cache Monitoring Technology) [1] is a H/W feature that reports cache
> occupancy of a process. resctrl selftest suite has a unit test to test CMT
> for LLC but the test is named as CQM (Cache Quality Monitoring).
> Furthermore, the unit test source file is named as cqm_test.c and several
> functions, variables, comments, preprocessors and statements widely use
> "cqm" as either suffix or prefix. This rampant misusage of CQM for CMT
> might confuse someone who is newly looking at resctrl selftests because
> this feature is named CMT in the Intel Software Developer's Manual.
> 
> Hence, rename all the occurrences (unit test source file name, functions,
> variables, comments and preprocessors) of cqm with cmt.
> 
> [1] Please see Intel SDM, Volume 3, chapter 17 and section 18 for more
>      information on CMT.

Link please?

> 
> Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")

Why is this a fix though? Quote the commit in the commit log and
please remove Fixes tag. No need to confuse tools that look for
Fixes tag to select patches for stables.

> Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
> ---
>   tools/testing/selftests/resctrl/README        |  4 +--
>   tools/testing/selftests/resctrl/cache.c       |  4 +--
>   .../resctrl/{cqm_test.c => cmt_test.c}        | 20 +++++++-------
>   tools/testing/selftests/resctrl/resctrl.h     |  4 +--
>   .../testing/selftests/resctrl/resctrl_tests.c | 26 +++++++++----------
>   tools/testing/selftests/resctrl/resctrl_val.c | 12 ++++-----
>   tools/testing/selftests/resctrl/resctrlfs.c   | 10 +++----
>   7 files changed, 40 insertions(+), 40 deletions(-)
>   rename tools/testing/selftests/resctrl/{cqm_test.c => cmt_test.c} (89%)
> 
> diff --git a/tools/testing/selftests/resctrl/README b/tools/testing/selftests/resctrl/README
> index 6e5a0ffa18e8..4b36b25b6ac0 100644
> --- a/tools/testing/selftests/resctrl/README
> +++ b/tools/testing/selftests/resctrl/README
> @@ -46,8 +46,8 @@ ARGUMENTS
>   Parameter '-h' shows usage information.
>   
>   usage: resctrl_tests [-h] [-b "benchmark_cmd [options]"] [-t test list] [-n no_of_bits]
> -        -b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CQM default benchmark is builtin fill_buf
> -        -t test list: run tests specified in the test list, e.g. -t mbm, mba, cqm, cat
> +        -b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CMT default benchmark is builtin fill_buf
> +        -t test list: run tests specified in the test list, e.g. -t mbm, mba, cmt, cat
>           -n no_of_bits: run cache tests using specified no of bits in cache bit mask
>           -p cpu_no: specify CPU number to run the test. 1 is default
>           -h: help
> diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c
> index 38dbf4962e33..4d73edd81293 100644
> --- a/tools/testing/selftests/resctrl/cache.c
> +++ b/tools/testing/selftests/resctrl/cache.c
> @@ -111,7 +111,7 @@ static int get_llc_perf(unsigned long *llc_perf_miss)
>   
>   /*
>    * Get LLC Occupancy as reported by RESCTRL FS
> - * For CQM,
> + * For CMT,
>    * 1. If con_mon grp and mon grp given, then read from mon grp in
>    * con_mon grp
>    * 2. If only con_mon grp given, then read from con_mon grp
> @@ -192,7 +192,7 @@ int measure_cache_vals(struct resctrl_val_param *param, int bm_pid)
>   	/*
>   	 * Measure llc occupancy from resctrl.
>   	 */
> -	if (!strcmp(param->resctrl_val, "cqm")) {
> +	if (!strcmp(param->resctrl_val, "cmt")) {
>   		ret = get_llc_occu_resctrl(&llc_occu_resc);
>   		if (ret < 0)
>   			return ret;
> diff --git a/tools/testing/selftests/resctrl/cqm_test.c b/tools/testing/selftests/resctrl/cmt_test.c
> similarity index 89%
> rename from tools/testing/selftests/resctrl/cqm_test.c
> rename to tools/testing/selftests/resctrl/cmt_test.c
> index c8756152bd61..13b01e010238 100644
> --- a/tools/testing/selftests/resctrl/cqm_test.c
> +++ b/tools/testing/selftests/resctrl/cmt_test.c
> @@ -1,6 +1,6 @@
>   // SPDX-License-Identifier: GPL-2.0
>   /*
> - * Cache Monitoring Technology (CQM) test
> + * Cache Monitoring Technology (CMT) test
>    *
>    * Copyright (C) 2018 Intel Corporation
>    *
> @@ -11,7 +11,7 @@
>   #include "resctrl.h"
>   #include <unistd.h>
>   
> -#define RESULT_FILE_NAME	"result_cqm"
> +#define RESULT_FILE_NAME	"result_cmt"
>   #define NUM_OF_RUNS		5
>   #define MAX_DIFF		2000000
>   #define MAX_DIFF_PERCENT	15
> @@ -21,7 +21,7 @@ char cbm_mask[256];
>   unsigned long long_mask;
>   unsigned long cache_size;
>   
> -static int cqm_setup(int num, ...)
> +static int cmt_setup(int num, ...)
>   {
>   	struct resctrl_val_param *p;
>   	va_list param;
> @@ -58,7 +58,7 @@ static void show_cache_info(unsigned long sum_llc_occu_resc, int no_of_bits,
>   	else
>   		res = false;
>   
> -	printf("%sok CQM: diff within %d, %d\%%\n", res ? "" : "not",
> +	printf("%sok CMT: diff within %d, %d\%%\n", res ? "" : "not",
>   	       MAX_DIFF, (int)MAX_DIFF_PERCENT);
>   
>   	printf("# diff: %ld\n", avg_diff);
> @@ -106,12 +106,12 @@ static int check_results(struct resctrl_val_param *param, int no_of_bits)
>   	return 0;
>   }
>   
> -void cqm_test_cleanup(void)
> +void cmt_test_cleanup(void)
>   {
>   	remove(RESULT_FILE_NAME);
>   }
>   
> -int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
> +int cmt_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
>   {
>   	int ret, mum_resctrlfs;
>   
> @@ -122,7 +122,7 @@ int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
>   	if (ret)
>   		return ret;
>   
> -	if (!validate_resctrl_feature_request("cqm"))
> +	if (!validate_resctrl_feature_request("cmt"))
>   		return -1;
>   
>   	ret = get_cbm_mask("L3");
> @@ -145,7 +145,7 @@ int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
>   	}
>   
>   	struct resctrl_val_param param = {
> -		.resctrl_val	= "cqm",
> +		.resctrl_val	= "cmt",
>   		.ctrlgrp	= "c1",
>   		.mongrp		= "m1",
>   		.cpu_no		= cpu_no,
> @@ -154,7 +154,7 @@ int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
>   		.mask		= ~(long_mask << n) & long_mask,
>   		.span		= cache_size * n / count_of_bits,
>   		.num_of_runs	= 0,
> -		.setup		= cqm_setup,
> +		.setup		= cmt_setup,
>   	};
>   
>   	if (strcmp(benchmark_cmd[0], "fill_buf") == 0)
> @@ -170,7 +170,7 @@ int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
>   	if (ret)
>   		return ret;
>   
> -	cqm_test_cleanup();
> +	cmt_test_cleanup();
>   
>   	return 0;
>   }
> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
> index 39bf59c6b9c5..68522b19b235 100644
> --- a/tools/testing/selftests/resctrl/resctrl.h
> +++ b/tools/testing/selftests/resctrl/resctrl.h
> @@ -98,9 +98,9 @@ void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
>   int cat_val(struct resctrl_val_param *param);
>   void cat_test_cleanup(void);
>   int cat_perf_miss_val(int cpu_no, int no_of_bits, char *cache_type);
> -int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd);
> +int cmt_resctrl_val(int cpu_no, int n, char **benchmark_cmd);
>   unsigned int count_bits(unsigned long n);
> -void cqm_test_cleanup(void);
> +void cmt_test_cleanup(void);
>   int get_core_sibling(int cpu_no);
>   int measure_cache_vals(struct resctrl_val_param *param, int bm_pid);
>   
> diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
> index 425cc85ac883..35a91cab1b88 100644
> --- a/tools/testing/selftests/resctrl/resctrl_tests.c
> +++ b/tools/testing/selftests/resctrl/resctrl_tests.c
> @@ -37,10 +37,10 @@ void detect_amd(void)
>   static void cmd_help(void)
>   {
>   	printf("usage: resctrl_tests [-h] [-b \"benchmark_cmd [options]\"] [-t test list] [-n no_of_bits]\n");
> -	printf("\t-b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CQM");
> +	printf("\t-b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CMT");
>   	printf("\t default benchmark is builtin fill_buf\n");
>   	printf("\t-t test list: run tests specified in the test list, ");
> -	printf("e.g. -t mbm, mba, cqm, cat\n");
> +	printf("e.g. -t mbm, mba, cmt, cat\n");
>   	printf("\t-n no_of_bits: run cache tests using specified no of bits in cache bit mask\n");
>   	printf("\t-p cpu_no: specify CPU number to run the test. 1 is default\n");
>   	printf("\t-h: help\n");
> @@ -50,13 +50,13 @@ void tests_cleanup(void)
>   {
>   	mbm_test_cleanup();
>   	mba_test_cleanup();
> -	cqm_test_cleanup();
> +	cmt_test_cleanup();
>   	cat_test_cleanup();
>   }
>   
>   int main(int argc, char **argv)
>   {
> -	bool has_ben = false, mbm_test = true, mba_test = true, cqm_test = true;
> +	bool has_ben = false, mbm_test = true, mba_test = true, cmt_test = true;
>   	int res, c, cpu_no = 1, span = 250, argc_new = argc, i, no_of_bits = 5;
>   	char *benchmark_cmd[BENCHMARK_ARGS], bw_report[64], bm_type[64];
>   	char benchmark_cmd_area[BENCHMARK_ARGS][BENCHMARK_ARG_SIZE];
> @@ -82,15 +82,15 @@ int main(int argc, char **argv)
>   
>   			mbm_test = false;
>   			mba_test = false;
> -			cqm_test = false;
> +			cmt_test = false;
>   			cat_test = false;
>   			while (token) {
>   				if (!strcmp(token, "mbm")) {
>   					mbm_test = true;
>   				} else if (!strcmp(token, "mba")) {
>   					mba_test = true;
> -				} else if (!strcmp(token, "cqm")) {
> -					cqm_test = true;
> +				} else if (!strcmp(token, "cmt")) {
> +					cmt_test = true;
>   				} else if (!strcmp(token, "cat")) {
>   					cat_test = true;

Why not use strncmp() here. Also, this code can be cleaned up.
This is error prone. It appears there is a link to these tokens
and offset in the benchmark_cmd[].

>   				} else {
> @@ -178,13 +178,13 @@ int main(int argc, char **argv)
>   		tests_run++;
>   	}
>   
> -	if (cqm_test) {
> -		printf("# Starting CQM test ...\n");
> +	if (cmt_test) {
> +		printf("# Starting CMT test ...\n");
>   		if (!has_ben)
> -			sprintf(benchmark_cmd[5], "%s", "cqm");
> -		res = cqm_resctrl_val(cpu_no, no_of_bits, benchmark_cmd);
> -		printf("%sok CQM: test\n", res ? "not " : "");
> -		cqm_test_cleanup();
> +			sprintf(benchmark_cmd[5], "%s", "cmt");

Like here. Why not add defines that make it easier to read.

> +		res = cmt_resctrl_val(cpu_no, no_of_bits, benchmark_cmd);
> +		printf("%sok CMT: test\n", res ? "not " : "");
> +		cmt_test_cleanup();
>   		tests_run++;
>   	}
>   
> diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
> index 520fea3606d1..270cd95e0026 100644
> --- a/tools/testing/selftests/resctrl/resctrl_val.c
> +++ b/tools/testing/selftests/resctrl/resctrl_val.c
> @@ -492,7 +492,7 @@ static int print_results_bw(char *filename,  int bm_pid, float bw_imc,
>   	return 0;
>   }
>   
> -static void set_cqm_path(const char *ctrlgrp, const char *mongrp, char sock_num)
> +static 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,
> @@ -512,7 +512,7 @@ static void set_cqm_path(const char *ctrlgrp, const char *mongrp, char sock_num)
>    * @ctrlgrp:			Name of the control monitor group (con_mon grp)
>    * @mongrp:			Name of the monitor group (mon grp)
>    * @cpu_no:			CPU number that the benchmark PID is binded to
> - * @resctrl_val:		Resctrl feature (Eg: cat, cqm.. etc)
> + * @resctrl_val:		Resctrl feature (Eg: cat, cmt.. etc)
>    */
>   static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp,
>   					int cpu_no, char *resctrl_val)
> @@ -524,8 +524,8 @@ static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp,
>   		return;
>   	}
>   
> -	if (strcmp(resctrl_val, "cqm") == 0)
> -		set_cqm_path(ctrlgrp, mongrp, resource_id);
> +	if (strcmp(resctrl_val, "cmt") == 0)
> +		set_cmt_path(ctrlgrp, mongrp, resource_id);

Why aren't these strncmp()s. Also these command strings are hard coded
over a over again. Why not add defines for these.

>   }
>   
>   static int
> @@ -682,7 +682,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
>   
>   		initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp,
>   					  param->cpu_no, resctrl_val);
> -	} else if (strcmp(resctrl_val, "cqm") == 0)
> +	} else if (strcmp(resctrl_val, "cmt") == 0)
>   		initialize_llc_occu_resctrl(param->ctrlgrp, param->mongrp,
>   					    param->cpu_no, resctrl_val);
>   
> @@ -721,7 +721,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
>   			ret = measure_vals(param, &bw_resc_start);
>   			if (ret)
>   				break;
> -		} else if (strcmp(resctrl_val, "cqm") == 0) {
> +		} else if (strcmp(resctrl_val, "cmt") == 0) {
>   			ret = param->setup(1, param);
>   			if (ret) {
>   				ret = 0;
> diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
> index 19c0ec4045a4..727e667e2cc9 100644
> --- a/tools/testing/selftests/resctrl/resctrlfs.c
> +++ b/tools/testing/selftests/resctrl/resctrlfs.c
> @@ -334,7 +334,7 @@ void run_benchmark(int signum, siginfo_t *info, void *ucontext)
>   		operation = atoi(benchmark_cmd[4]);
>   		sprintf(resctrl_val, "%s", benchmark_cmd[5]);
>   
> -		if (strcmp(resctrl_val, "cqm") != 0)
> +		if (strcmp(resctrl_val, "cmt") != 0)
>   			buffer_span = span * MB;
>   		else
>   			buffer_span = span;
> @@ -458,8 +458,8 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
>   	if (ret)
>   		goto out;
>   
> -	/* Create mon grp and write pid into it for "mbm" and "cqm" test */
> -	if ((strcmp(resctrl_val, "cqm") == 0) ||
> +	/* Create mon grp and write pid into it for "mbm" and "cmt" test */
> +	if ((strcmp(resctrl_val, "cmt") == 0) ||
>   	    (strcmp(resctrl_val, "mbm") == 0)) {
>   		if (strlen(mongrp)) {
>   			sprintf(monitorgroup_p, "%s/mon_groups", controlgroup);
> @@ -507,7 +507,7 @@ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
>   
>   	if ((strcmp(resctrl_val, "mba") != 0) &&
>   	    (strcmp(resctrl_val, "cat") != 0) &&
> -	    (strcmp(resctrl_val, "cqm") != 0))
> +	    (strcmp(resctrl_val, "cmt") != 0))
>   		return -ENOENT;
>   
>   	if (!schemata) {
> @@ -528,7 +528,7 @@ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
>   	else
>   		sprintf(controlgroup, "%s/schemata", RESCTRL_PATH);
>   
> -	if (!strcmp(resctrl_val, "cat") || !strcmp(resctrl_val, "cqm"))
> +	if (!strcmp(resctrl_val, "cat") || !strcmp(resctrl_val, "cmt"))
>   		sprintf(schema, "%s%d%c%s", "L3:", resource_id, '=', schemata);
>   	if (strcmp(resctrl_val, "mba") == 0)
>   		sprintf(schema, "%s%d%c%s", "MB:", resource_id, '=', schemata);
> 

Let's clean this test up.
thanks,
-- Shuah

[PATCH v3 02/21] selftests/resctrl: Fix typo

[Fenghua Yu]

From: Reinette Chatre <reinette.chatre@intel.com>

The format "%sok" is used to print results of a test. If the test passes,
the empty string is printed and if the test fails "not " is printed. This
results in output of "ok" when test passes and "not ok"
when test fails.

Fix one instance where "not" (without a space) is printed on test
failure resulting in output of "notok" on test failure.

Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/cmt_test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index 13b01e010238..6ffb56c6a1e2 100644
--- a/tools/testing/selftests/resctrl/cmt_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -58,7 +58,7 @@ static void show_cache_info(unsigned long sum_llc_occu_resc, int no_of_bits,
 	else
 		res = false;
 
-	printf("%sok CMT: diff within %d, %d\%%\n", res ? "" : "not",
+	printf("%sok CMT: diff within %d, %d\%%\n", res ? "" : "not ",
 	       MAX_DIFF, (int)MAX_DIFF_PERCENT);
 
 	printf("# diff: %ld\n", avg_diff);
-- 
2.29.0

Re: [PATCH v3 02/21] selftests/resctrl: Fix typo

[Shuah Khan]

On 10/20/20 5:51 PM, Fenghua Yu wrote:
> From: Reinette Chatre <reinette.chatre@intel.com>
> 
> The format "%sok" is used to print results of a test. If the test passes,
> the empty string is printed and if the test fails "not " is printed. This
> results in output of "ok" when test passes and "not ok"
> when test fails.
> 
> Fix one instance where "not" (without a space) is printed on test
> failure resulting in output of "notok" on test failure.
> 

The commit summary is misleading. It isn't typo. You are adding
a space to make the message correct?

> Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
> ---
>   tools/testing/selftests/resctrl/cmt_test.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
> index 13b01e010238..6ffb56c6a1e2 100644
> --- a/tools/testing/selftests/resctrl/cmt_test.c
> +++ b/tools/testing/selftests/resctrl/cmt_test.c
> @@ -58,7 +58,7 @@ static void show_cache_info(unsigned long sum_llc_occu_resc, int no_of_bits,
>   	else
>   		res = false;
>   
> -	printf("%sok CMT: diff within %d, %d\%%\n", res ? "" : "not",
> +	printf("%sok CMT: diff within %d, %d\%%\n", res ? "" : "not ",
>   	       MAX_DIFF, (int)MAX_DIFF_PERCENT);
>   
>   	printf("# diff: %ld\n", avg_diff);
> 

thanks,
-- Shuah

[PATCH v3 03/21] selftests/resctrl: Fix typo in help text

[Fenghua Yu]

From: Reinette Chatre <reinette.chatre@intel.com>

Add a missing newline to the help text printed and fixup the next line
to line it up to previous line for improved readability.

Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrl_tests.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index 35a91cab1b88..b2a560c0c5dc 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -37,8 +37,8 @@ void detect_amd(void)
 static void cmd_help(void)
 {
 	printf("usage: resctrl_tests [-h] [-b \"benchmark_cmd [options]\"] [-t test list] [-n no_of_bits]\n");
-	printf("\t-b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CMT");
-	printf("\t default benchmark is builtin fill_buf\n");
+	printf("\t-b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CMT\n");
+	printf("\t   default benchmark is builtin fill_buf\n");
 	printf("\t-t test list: run tests specified in the test list, ");
 	printf("e.g. -t mbm, mba, cmt, cat\n");
 	printf("\t-n no_of_bits: run cache tests using specified no of bits in cache bit mask\n");
-- 
2.29.0

Re: [PATCH v3 03/21] selftests/resctrl: Fix typo in help text

[Shuah Khan]

On 10/20/20 5:51 PM, Fenghua Yu wrote:
> From: Reinette Chatre <reinette.chatre@intel.com>
> 
> Add a missing newline to the help text printed and fixup the next line
> to line it up to previous line for improved readability.
> 
> Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
> ---
>   tools/testing/selftests/resctrl/resctrl_tests.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
> index 35a91cab1b88..b2a560c0c5dc 100644
> --- a/tools/testing/selftests/resctrl/resctrl_tests.c
> +++ b/tools/testing/selftests/resctrl/resctrl_tests.c
> @@ -37,8 +37,8 @@ void detect_amd(void)
>   static void cmd_help(void)
>   {
>   	printf("usage: resctrl_tests [-h] [-b \"benchmark_cmd [options]\"] [-t test list] [-n no_of_bits]\n");
> -	printf("\t-b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CMT");
> -	printf("\t default benchmark is builtin fill_buf\n");
> +	printf("\t-b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CMT\n");
> +	printf("\t   default benchmark is builtin fill_buf\n");
>   	printf("\t-t test list: run tests specified in the test list, ");
>   	printf("e.g. -t mbm, mba, cmt, cat\n");
>   	printf("\t-n no_of_bits: run cache tests using specified no of bits in cache bit mask\n");
> 

The commit summary is misleading. It isn't typo. You are adding
a space to make the message correct?

thanks,
-- Shuah

[PATCH v3 04/21] selftests/resctrl: Declare global variables as extern

[Fenghua Yu]

resctrl test suite uses global variables (E.g: bm_pid, ppid, llc_occup_path
and is_amd) that are used across .c files. These global variables are
defined in resctrl.h file and the header file is included in .c files where
needed. Sparse tool isn't very happy about defining global variables in .h
file and hence complains as below

resctrl.h:65:7: warning: symbol 'bm_pid' was not declared.
		Should it be static?
resctrl.h:65:15: warning: symbol 'ppid' was not declared.
		 Should it be static?
resctrl.h:66:5: warning: symbol 'tests_run' was not declared.
		Should it be static?
resctrl.h:68:6: warning: symbol 'llc_occup_path' was not declared.
		Should it be static?
resctrl.h:69:6: warning: symbol 'is_amd' was not declared.
		Should it be static?

Sparse tool thinks that since the variables are defined and not declared,
it assumes that the scope of these variables is limited to a .c file and
hence suggests making them static variables. But these variables are used
across .c files and hence cannot be static variables.

Fix these warnings by declaring the variables (i.e. use extern keyword)
rather than defining them in resctrl.h file.

Please note that sparse tool still complains about other issues and they
will be fixed in later patches.

Fixes: 591a6e8588fc ("selftests/resctrl: Add basic resctrl file
system operations and data")
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrl.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index 68522b19b235..814d0dd517a4 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -62,11 +62,11 @@ struct resctrl_val_param {
 	int		(*setup)(int num, ...);
 };
 
-pid_t bm_pid, ppid;
-int tests_run;
+extern pid_t bm_pid, ppid;
+extern int tests_run;
 
-char llc_occup_path[1024];
-bool is_amd;
+extern char llc_occup_path[1024];
+extern bool is_amd;
 
 bool check_resctrlfs_support(void);
 int filter_dmesg(void);
-- 
2.29.0

[PATCH v3 05/21] selftests/resctrl: Return if resctrl file system is not supported

[Fenghua Yu]

check_resctrlfs_support() checks if the platform supports resctrl file
system or not by looking for resctrl in /proc/filesystems and returns a
boolean value. The main function of resctrl test suite calls
check_resctrlfs_support() but forgets to check for it's return value. This
means that resctrl test suite will attempt to run resctrl tests (like CMT,
CAT, MBM and MBA) even if the platform doesn't support resctrl file system.

Fix this by checking for the return value of check_resctrlfs_support() in
the main function. If resctrl file system isn't supported on the platform
then exit the test suite gracefully without attempting to run any of
resctrl unit tests.

Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrl_tests.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index b2a560c0c5dc..d24de546d4ef 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -155,7 +155,11 @@ int main(int argc, char **argv)
 	sprintf(bw_report, "reads");
 	sprintf(bm_type, "fill_buf");
 
-	check_resctrlfs_support();
+	if (!check_resctrlfs_support()) {
+		printf("Bail out! resctrl FS does not exist\n");
+		goto out;
+	}
+
 	filter_dmesg();
 
 	if (!is_amd && mbm_test) {
@@ -196,6 +200,7 @@ int main(int argc, char **argv)
 		cat_test_cleanup();
 	}
 
+out:
 	printf("1..%d\n", tests_run);
 
 	return 0;
-- 
2.29.0

Re: [PATCH v3 05/21] selftests/resctrl: Return if resctrl file system is not supported

[Shuah Khan]

On 10/20/20 5:51 PM, Fenghua Yu wrote:
> check_resctrlfs_support() checks if the platform supports resctrl file
> system or not by looking for resctrl in /proc/filesystems and returns a
> boolean value. The main function of resctrl test suite calls
> check_resctrlfs_support() but forgets to check for it's return value. This
> means that resctrl test suite will attempt to run resctrl tests (like CMT,
> CAT, MBM and MBA) even if the platform doesn't support resctrl file system.
> 
> Fix this by checking for the return value of check_resctrlfs_support() in
> the main function. If resctrl file system isn't supported on the platform
> then exit the test suite gracefully without attempting to run any of
> resctrl unit tests.
> 
> Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
> ---
>   tools/testing/selftests/resctrl/resctrl_tests.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
> index b2a560c0c5dc..d24de546d4ef 100644
> --- a/tools/testing/selftests/resctrl/resctrl_tests.c
> +++ b/tools/testing/selftests/resctrl/resctrl_tests.c
> @@ -155,7 +155,11 @@ int main(int argc, char **argv)
>   	sprintf(bw_report, "reads");
>   	sprintf(bm_type, "fill_buf");
>   
> -	check_resctrlfs_support();
> +	if (!check_resctrlfs_support()) {
> +		printf("Bail out! resctrl FS does not exist\n");
> +		goto out;
> +	}
> +

Adding config file makes sense to specify dependencies.

>   	filter_dmesg();
>   
>   	if (!is_amd && mbm_test) {
> @@ -196,6 +200,7 @@ int main(int argc, char **argv)
>   		cat_test_cleanup();
>   	}
>   
> +out:
>   	printf("1..%d\n", tests_run);
>   
>   	return 0;
> 

thanks,
-- Shuah

[PATCH v3 06/21] selftests/resctrl: Check for resctrl mount point only if resctrl FS is supported

[Fenghua Yu]

check_resctrlfs_support() does the following
1. Checks if the platform supports resctrl file system or not by looking
   for resctrl in /proc/filesystems
2. Calls opendir() on default resctrl file system path
   (i.e. /sys/fs/resctrl)
3. Checks if resctrl file system is mounted or not by looking at
   /proc/mounts

Steps 2 and 3 will fail if the platform does not support resctrl file
system. So, there is no need to check for them if step 1 fails.

Fix this by returning immediately if the platform does not support
resctrl file system.

Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrlfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 727e667e2cc9..e43ddebd1aa4 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -581,6 +581,9 @@ bool check_resctrlfs_support(void)
 	printf("%sok kernel supports resctrl filesystem\n", ret ? "" : "not ");
 	tests_run++;
 
+	if (!ret)
+		return ret;
+
 	dp = opendir(RESCTRL_PATH);
 	printf("%sok resctrl mountpoint \"%s\" exists\n",
 	       dp ? "" : "not ", RESCTRL_PATH);
-- 
2.29.0

[PATCH v3 07/21] selftests/resctrl: Use resctrl/info for feature detection

[Fenghua Yu]

Resctrl test suite before running any unit test (like cmt, cat, mbm and
mba) should first check if the feature is enabled (by kernel and not just
supported by H/W) on the platform or not.
validate_resctrl_feature_request() is supposed to do that. This function
intends to grep for relevant flags in /proc/cpuinfo but there are several
issues here

1. validate_resctrl_feature_request() calls fgrep() to get flags from
   /proc/cpuinfo. But, fgrep() can only return a string with maximum of 255
   characters and hence the complete cpu flags are never returned.
2. The substring search logic is also busted. If strstr() finds requested
   resctrl feature in the cpu flags, it returns pointer to the first
   occurrence. But, the logic negates the return value of strstr() and
   hence validate_resctrl_feature_request() returns false if the feature is
   present in the cpu flags and returns true if the feature is not present.
3. validate_resctrl_feature_request() checks if a resctrl feature is
   reported in /proc/cpuinfo flags or not. Having a cpu flag means that the
   H/W supports the feature, but it doesn't mean that the kernel enabled
   it. A user could selectively enable only a subset of resctrl features
   using kernel command line arguments. Hence, /proc/cpuinfo isn't a
   reliable source to check if a feature is enabled or not.

The 3rd issue being the major one and fixing it requires changing the way
validate_resctrl_feature_request() works. Since, /proc/cpuinfo isn't the
right place to check if a resctrl feature is enabled or not, a more
appropriate place is /sys/fs/resctrl/info directory. Change
validate_resctrl_feature_request() such that,

1. For cat, check if /sys/fs/resctrl/info/L3 directory is present or not
2. For mba, check if /sys/fs/resctrl/info/MB directory is present or not
3. For cmt, check if /sys/fs/resctrl/info/L3_MON directory is present and
   check if /sys/fs/resctrl/info/L3_MON/mon_features has llc_occupancy
4. For mbm, check if /sys/fs/resctrl/info/L3_MON directory is present and
   check if /sys/fs/resctrl/info/L3_MON/mon_features has
   mbm_<total/local>_bytes

Please note that only L3_CAT, L3_CMT, MBA and MBM are supported. CDP and L2
variants can be added later.

Fixes: 591a6e8588fc ("selftests/resctrl: Add basic resctrl file system operations and data")
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrl.h   |  6 ++-
 tools/testing/selftests/resctrl/resctrlfs.c | 51 ++++++++++++++++-----
 2 files changed, 45 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index 814d0dd517a4..65ca24bf3eac 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -28,6 +28,10 @@
 #define RESCTRL_PATH		"/sys/fs/resctrl"
 #define PHYS_ID_PATH		"/sys/devices/system/cpu/cpu"
 #define CBM_MASK_PATH		"/sys/fs/resctrl/info"
+#define L3_PATH			"/sys/fs/resctrl/info/L3"
+#define MB_PATH			"/sys/fs/resctrl/info/MB"
+#define L3_MON_PATH		"/sys/fs/resctrl/info/L3_MON"
+#define L3_MON_FEATURES_PATH	"/sys/fs/resctrl/info/L3_MON/mon_features"
 
 #define PARENT_EXIT(err_msg)			\
 	do {					\
@@ -74,7 +78,7 @@ int remount_resctrlfs(bool mum_resctrlfs);
 int get_resource_id(int cpu_no, int *resource_id);
 int umount_resctrlfs(void);
 int validate_bw_report_request(char *bw_report);
-bool validate_resctrl_feature_request(char *resctrl_val);
+bool validate_resctrl_feature_request(const char *resctrl_val);
 char *fgrep(FILE *inf, const char *str);
 int taskset_benchmark(pid_t bm_pid, int cpu_no);
 void run_benchmark(int signum, siginfo_t *info, void *ucontext);
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index e43ddebd1aa4..67d775d03271 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -618,26 +618,55 @@ char *fgrep(FILE *inf, const char *str)
  * validate_resctrl_feature_request - Check if requested feature is valid.
  * @resctrl_val:	Requested feature
  *
- * Return: 0 on success, non-zero on failure
+ * Return: True if the feature is supported, else false
  */
-bool validate_resctrl_feature_request(char *resctrl_val)
+bool validate_resctrl_feature_request(const char *resctrl_val)
 {
-	FILE *inf = fopen("/proc/cpuinfo", "r");
+	struct stat statbuf;
 	bool found = false;
 	char *res;
+	FILE *inf;
 
-	if (!inf)
+	if (!resctrl_val)
 		return false;
 
-	res = fgrep(inf, "flags");
-
-	if (res) {
-		char *s = strchr(res, ':');
+	if (remount_resctrlfs(false))
+		return false;
 
-		found = s && !strstr(s, resctrl_val);
-		free(res);
+	if (!strcmp(resctrl_val, "cat")) {
+		if (!stat(L3_PATH, &statbuf))
+			return true;
+	} else if (!strcmp(resctrl_val, "mba")) {
+		if (!stat(MB_PATH, &statbuf))
+			return true;
+	} else if (!strcmp(resctrl_val, "mbm") || !strcmp(resctrl_val, "cmt")) {
+		if (!stat(L3_MON_PATH, &statbuf)) {
+			inf = fopen(L3_MON_FEATURES_PATH, "r");
+			if (!inf)
+				return false;
+
+			if (!strcmp(resctrl_val, "cmt")) {
+				res = fgrep(inf, "llc_occupancy");
+				if (res) {
+					found = true;
+					free(res);
+				}
+			}
+
+			if (!strcmp(resctrl_val, "mbm")) {
+				res = fgrep(inf, "mbm_total_bytes");
+				if (res) {
+					free(res);
+					res = fgrep(inf, "mbm_local_bytes");
+					if (res) {
+						found = true;
+						free(res);
+					}
+				}
+			}
+			fclose(inf);
+		}
 	}
-	fclose(inf);
 
 	return found;
 }
-- 
2.29.0

[PATCH v3 08/21] selftests/resctrl: Ensure sibling CPU is not same as original CPU

[Fenghua Yu]

From: Reinette Chatre <reinette.chatre@intel.com>

The resctrl tests can accept a CPU on which the tests are run and use
default of CPU #1 if it is not provided. In the CAT test a "sibling CPU"
is determined that is from the same package where another thread will be
run.

The current algorithm with which a "sibling CPU" is determined does not
take the provided/default CPU into account and when that CPU is the
first CPU in a package then the "sibling CPU" will be selected to be the
same CPU since it starts by picking the first CPU from core_siblings_list.

Fix the "sibling CPU" selection by taking the provided/default CPU into
account and ensuring a sibling that is a different CPU is selected.

Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrlfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 67d775d03271..05956319d9ce 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -268,7 +268,7 @@ int get_core_sibling(int cpu_no)
 	while (token) {
 		sibling_cpu_no = atoi(token);
 		/* Skipping core 0 as we don't want to run test on core 0 */
-		if (sibling_cpu_no != 0)
+		if (sibling_cpu_no != 0 && sibling_cpu_no != cpu_no)
 			break;
 		token = strtok(NULL, "-,");
 	}
-- 
2.29.0

[PATCH v3 09/21] selftests/resctrl: Fix missing options "-n" and "-p"

[Fenghua Yu]

resctrl test suite accepts command line arguments (like -b, -t, -n and -p)
as documented in the help. But passing -n and -p throws an invalid option
error. This happens because -n and -p are missing in the list of
characters that getopt() recognizes as valid arguments. Hence, they are
treated as invalid options.

Fix this by adding them to the list of characters that getopt() recognizes
as valid arguments. Please note that the main() function already has the
logic to deal with the values passed as part of these arguments and hence
no changes are needed there.

Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrl_tests.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index d24de546d4ef..cab69ed8c67d 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -73,7 +73,7 @@ int main(int argc, char **argv)
 		}
 	}
 
-	while ((c = getopt(argc_new, argv, "ht:b:")) != -1) {
+	while ((c = getopt(argc_new, argv, "ht:b:n:p:")) != -1) {
 		char *token;
 
 		switch (c) {
-- 
2.29.0

[PATCH v3 10/21] selftests/resctrl: Fix MBA/MBM results reporting format

[Fenghua Yu]

MBM unit test starts fill_buf (default built-in benchmark) in a new con_mon
group (c1, m1) and records resctrl reported mbm values and iMC (Integrated
Memory Controller) values every second. It does this for five seconds
(randomly chosen value) in total. It then calculates average of resctrl_mbm
values and imc_mbm values and if the difference is greater than 300 MB/sec
(randomly chosen value), the test treats it as a failure. MBA unit test is
similar to MBM but after every run it changes schemata.

Checking for a difference of 300 MB/sec doesn't look very meaningful when
the mbm values are changing over a wide range. For example, below are the
values running MBA test on SKL with different allocations

1. With 10% as schemata both iMC and resctrl mbm_values are around 2000
   MB/sec
2. With 100% as schemata both iMC and resctrl mbm_values are around 10000
   MB/sec

A 300 MB/sec difference between resctrl_mbm and imc_mbm values is
acceptable at 100% schemata but it isn't acceptable at 10% schemata because
that's a huge difference.

So, fix this by checking for percentage difference instead of absolute
difference i.e. check if the difference between resctrl_mbm value and
imc_mbm value is within 5% (randomly chosen value) of imc_mbm value. If the
difference is greater than 5% of imc_mbm value, treat it is a failure.

Fixes: 01fee6b4d1f9 ("selftests/resctrl: Add MBA test")
Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/mba_test.c | 20 +++++++++++---------
 tools/testing/selftests/resctrl/mbm_test.c | 13 +++++++------
 2 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c
index 7bf8eaa6204b..ba0234d4829e 100644
--- a/tools/testing/selftests/resctrl/mba_test.c
+++ b/tools/testing/selftests/resctrl/mba_test.c
@@ -12,7 +12,7 @@
 
 #define RESULT_FILE_NAME	"result_mba"
 #define NUM_OF_RUNS		5
-#define MAX_DIFF		300
+#define MAX_DIFF_PERCENT	5
 #define ALLOCATION_MAX		100
 #define ALLOCATION_MIN		10
 #define ALLOCATION_STEP		10
@@ -62,7 +62,8 @@ static void show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
 	     allocation++) {
 		unsigned long avg_bw_imc, avg_bw_resc;
 		unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
-		unsigned long avg_diff;
+		int avg_diff_per;
+		float avg_diff;
 
 		/*
 		 * The first run is discarded due to inaccurate value from
@@ -76,17 +77,18 @@ static void show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
 
 		avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
 		avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
-		avg_diff = labs((long)(avg_bw_resc - avg_bw_imc));
+		avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
+		avg_diff_per = (int)(avg_diff * 100);
 
-		printf("%sok MBA schemata percentage %u smaller than %d %%\n",
-		       avg_diff > MAX_DIFF ? "not " : "",
-		       ALLOCATION_MAX - ALLOCATION_STEP * allocation,
-		       MAX_DIFF);
+		printf("%sok MBA: diff within %d%% for schemata %u\n",
+		       avg_diff_per > MAX_DIFF_PERCENT ? "not " : "",
+		       MAX_DIFF_PERCENT,
+		       ALLOCATION_MAX - ALLOCATION_STEP * allocation);
 		tests_run++;
-		printf("# avg_diff: %lu\n", avg_diff);
+		printf("# avg_diff_per: %d%%\n", avg_diff_per);
 		printf("# avg_bw_imc: %lu\n", avg_bw_imc);
 		printf("# avg_bw_resc: %lu\n", avg_bw_resc);
-		if (avg_diff > MAX_DIFF)
+		if (avg_diff_per > MAX_DIFF_PERCENT)
 			failed = true;
 	}
 
diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c
index 4700f7453f81..ca610c3ebc8c 100644
--- a/tools/testing/selftests/resctrl/mbm_test.c
+++ b/tools/testing/selftests/resctrl/mbm_test.c
@@ -11,7 +11,7 @@
 #include "resctrl.h"
 
 #define RESULT_FILE_NAME	"result_mbm"
-#define MAX_DIFF		300
+#define MAX_DIFF_PERCENT	5
 #define NUM_OF_RUNS		5
 
 static void
@@ -19,8 +19,8 @@ show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, int span)
 {
 	unsigned long avg_bw_imc = 0, avg_bw_resc = 0;
 	unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
-	long avg_diff = 0;
-	int runs;
+	int runs, avg_diff_per;
+	float avg_diff = 0;
 
 	/*
 	 * Discard the first value which is inaccurate due to monitoring setup
@@ -33,12 +33,13 @@ show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, int span)
 
 	avg_bw_imc = sum_bw_imc / 4;
 	avg_bw_resc = sum_bw_resc / 4;
-	avg_diff = avg_bw_resc - avg_bw_imc;
+	avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
+	avg_diff_per = (int)(avg_diff * 100);
 
 	printf("%sok MBM: diff within %d%%\n",
-	       labs(avg_diff) > MAX_DIFF ? "not " : "", MAX_DIFF);
+	       avg_diff_per > MAX_DIFF_PERCENT ? "not " : "", MAX_DIFF_PERCENT);
 	tests_run++;
-	printf("# avg_diff: %lu\n", labs(avg_diff));
+	printf("# avg_diff_per: %d%%\n", avg_diff_per);
 	printf("# Span (MB): %d\n", span);
 	printf("# avg_bw_imc: %lu\n", avg_bw_imc);
 	printf("# avg_bw_resc: %lu\n", avg_bw_resc);
-- 
2.29.0

[PATCH v3 11/21] selftests/resctrl: Abort running tests if not root user

[Fenghua Yu]

Running any resctrl unit test involves writing to resctrl file system and
only a root user has permission to write to resctrl FS. Resctrl test suite
before running any test checks for the privilege of the user and if it's
not a root user, the test suite prints a warning and continues attempting
to run tests.

Attempting to run any test without root privileges will fail as below

TAP version 13
ok kernel supports resctrl filesystem
.................
not ok mounting resctrl to "/sys/fs/resctrl"
not ok MBA: schemata change

Hence, don't attempt to run any test if the user is not a root user and
change the warning message to a bail out message to comply with TAP 13
standards.

Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrl_tests.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index cab69ed8c67d..f4867a81eee6 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -125,8 +125,10 @@ int main(int argc, char **argv)
 	 * 1. We write to resctrl FS
 	 * 2. We execute perf commands
 	 */
-	if (geteuid() != 0)
-		printf("# WARNING: not running as root, tests may fail.\n");
+	if (geteuid() != 0) {
+		printf("Bail out! not running as root, abort testing\n");
+		goto out;
+	}
 
 	/* Detect AMD vendor */
 	detect_amd();
-- 
2.29.0

[PATCH v3 12/21] selftests/resctrl: Enable gcc checks to detect buffer overflows

[Fenghua Yu]

David reported a buffer overflow error in the check_results() function of
the cmt unit test and he suggested enabling _FORTIFY_SOURCE gcc compiler
option to automatically detect any such errors.

Feature Test Macros man page describes_FORTIFY_SOURCE as below

"Defining this macro causes some lightweight checks to be performed to
detect some buffer overflow errors when employing various string and memory
manipulation functions (for example, memcpy, memset, stpcpy, strcpy,
strncpy, strcat, strncat, sprintf, snprintf, vsprintf, vsnprintf, gets, and
wide character variants thereof). For some functions, argument consistency
is checked; for example, a check is made that open has been supplied with a
mode argument when the specified flags include O_CREAT. Not all problems
are detected, just some common cases.

If _FORTIFY_SOURCE is set to 1, with compiler optimization level 1 (gcc
-O1) and above, checks that shouldn't change the behavior of conforming
programs are performed.

With _FORTIFY_SOURCE set to 2, some more checking is added, but some
conforming programs might fail.

Some of the checks can be performed at compile time (via macros logic
implemented in header files), and result in compiler warnings; other checks
take place at run time, and result in a run-time error if the check fails.

Use of this macro requires compiler support, available with gcc since
version 4.0."

Fix the buffer overflow error in the check_results() function of the cmt
unit test and enable _FORTIFY_SOURCE gcc check to catch any future buffer
overflow errors.

Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
Reported-by: David Binderman <dcb314@hotmail.com>
Suggested-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/Makefile   | 2 +-
 tools/testing/selftests/resctrl/cmt_test.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/resctrl/Makefile b/tools/testing/selftests/resctrl/Makefile
index d585cc1948cc..6bcee2ec91a9 100644
--- a/tools/testing/selftests/resctrl/Makefile
+++ b/tools/testing/selftests/resctrl/Makefile
@@ -1,5 +1,5 @@
 CC = $(CROSS_COMPILE)gcc
-CFLAGS = -g -Wall
+CFLAGS = -g -Wall -O2 -D_FORTIFY_SOURCE=2
 SRCS=$(wildcard *.c)
 OBJS=$(SRCS:.c=.o)
 
diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index 6ffb56c6a1e2..282ba7fcf17c 100644
--- a/tools/testing/selftests/resctrl/cmt_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -86,7 +86,7 @@ static int check_results(struct resctrl_val_param *param, int no_of_bits)
 		return errno;
 	}
 
-	while (fgets(temp, 1024, fp)) {
+	while (fgets(temp, sizeof(temp), fp)) {
 		char *token = strtok(temp, ":\t");
 		int fields = 0;
 
-- 
2.29.0

[PATCH v3 13/21] selftests/resctrl: Don't hard code value of "no_of_bits" variable

[Fenghua Yu]

Cache related tests (like CAT and CMT) depend on a variable called
no_of_bits to run. no_of_bits defines the number of contiguous bits
that should be set in the CBM mask and a user can pass a value for
no_of_bits using -n command line argument. If a user hasn't passed any
value, it defaults to 5 (randomly chosen value).

Hard coding no_of_bits to 5 will make the cache tests fail to run on
systems that support maximum cbm mask that is less than or equal to 5 bits.
Hence, don't hard code no_of_bits value.

If a user passes a value for "no_of_bits" using -n option, use it.
Otherwise, no_of_bits is equal to half of the maximum number of bits in
the cbm mask.

Please note that CMT test is still hard coded to 5 bits. It will change in
subsequent patches that change CMT test.

Fixes: 790bf585b0ee ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest")
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/cat_test.c      | 5 ++++-
 tools/testing/selftests/resctrl/resctrl_tests.c | 8 ++++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index 5da43767b973..1bce84e23783 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -151,7 +151,10 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
 	/* Get max number of bits from default-cabm mask */
 	count_of_bits = count_bits(long_mask);
 
-	if (n < 1 || n > count_of_bits - 1) {
+	if (!n)
+		n = count_of_bits / 2;
+
+	if (n > count_of_bits - 1) {
 		printf("Invalid input value for no_of_bits n!\n");
 		printf("Please Enter value in range 1 to %d\n",
 		       count_of_bits - 1);
diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index f4867a81eee6..5c217d0228f4 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -57,7 +57,7 @@ void tests_cleanup(void)
 int main(int argc, char **argv)
 {
 	bool has_ben = false, mbm_test = true, mba_test = true, cmt_test = true;
-	int res, c, cpu_no = 1, span = 250, argc_new = argc, i, no_of_bits = 5;
+	int res, c, cpu_no = 1, span = 250, argc_new = argc, i, no_of_bits = 0;
 	char *benchmark_cmd[BENCHMARK_ARGS], bw_report[64], bm_type[64];
 	char benchmark_cmd_area[BENCHMARK_ARGS][BENCHMARK_ARG_SIZE];
 	int ben_ind, ben_count;
@@ -106,6 +106,10 @@ int main(int argc, char **argv)
 			break;
 		case 'n':
 			no_of_bits = atoi(optarg);
+			if (no_of_bits <= 0) {
+				printf("Bail out! invalid argument for no_of_bits\n");
+				return -1;
+			}
 			break;
 		case 'h':
 			cmd_help();
@@ -188,7 +192,7 @@ int main(int argc, char **argv)
 		printf("# Starting CMT test ...\n");
 		if (!has_ben)
 			sprintf(benchmark_cmd[5], "%s", "cmt");
-		res = cmt_resctrl_val(cpu_no, no_of_bits, benchmark_cmd);
+		res = cmt_resctrl_val(cpu_no, 5, benchmark_cmd);
 		printf("%sok CMT: test\n", res ? "not " : "");
 		cmt_test_cleanup();
 		tests_run++;
-- 
2.29.0

[PATCH v3 14/21] selftests/resctrl: Modularize resctrl test suite main() function

[Fenghua Yu]

Resctrl test suite main() function does the following things
1. Parses command line arguments passed by user
2. Some setup checks
3. Logic that calls into each unit test
4. Print result and clean up after running each unit test

Introduce wrapper functions for steps 3 and 4 to modularize the main()
function. Adding these wrapper functions makes it easier to add any logic
to each individual test.

Please note that this is a preparatory patch for the next one and no
functional changes are intended.

Fixes: 01fee6b4d1f9 ("selftests/resctrl: Add MBA test")
Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Fixes: 78941183d1b15 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
Fixes: 790bf585b0eee ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 .../testing/selftests/resctrl/resctrl_tests.c | 96 ++++++++++++-------
 1 file changed, 61 insertions(+), 35 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index 5c217d0228f4..be7cd57efca8 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -54,10 +54,62 @@ void tests_cleanup(void)
 	cat_test_cleanup();
 }
 
+static void run_mbm_test(bool has_ben, char **benchmark_cmd, int span,
+			 int cpu_no, char *bw_report)
+{
+	int res;
+
+	printf("# Starting MBM BW change ...\n");
+	if (!has_ben)
+		sprintf(benchmark_cmd[5], "%s", "mba");
+	res = mbm_bw_change(span, cpu_no, bw_report, benchmark_cmd);
+	printf("%sok MBM: bw change\n", res ? "not " : "");
+	mbm_test_cleanup();
+	tests_run++;
+}
+
+static void run_mba_test(bool has_ben, char **benchmark_cmd, int span,
+			 int cpu_no, char *bw_report)
+{
+	int res;
+
+	printf("# Starting MBA Schemata change ...\n");
+	if (!has_ben)
+		sprintf(benchmark_cmd[1], "%d", span);
+	res = mba_schemata_change(cpu_no, bw_report, benchmark_cmd);
+	printf("%sok MBA: schemata change\n", res ? "not " : "");
+	mba_test_cleanup();
+	tests_run++;
+}
+
+static void run_cmt_test(bool has_ben, char **benchmark_cmd, int cpu_no)
+{
+	int res;
+
+	printf("# Starting CMT test ...\n");
+	if (!has_ben)
+		sprintf(benchmark_cmd[5], "%s", "cmt");
+	res = cmt_resctrl_val(cpu_no, 5, benchmark_cmd);
+	printf("%sok CMT: test\n", res ? "not " : "");
+	cmt_test_cleanup();
+	tests_run++;
+}
+
+static void run_cat_test(int cpu_no, int no_of_bits)
+{
+	int res;
+
+	printf("# Starting CAT test ...\n");
+	res = cat_perf_miss_val(cpu_no, no_of_bits, "L3");
+	printf("%sok CAT: test\n", res ? "not " : "");
+	tests_run++;
+	cat_test_cleanup();
+}
+
 int main(int argc, char **argv)
 {
 	bool has_ben = false, mbm_test = true, mba_test = true, cmt_test = true;
-	int res, c, cpu_no = 1, span = 250, argc_new = argc, i, no_of_bits = 0;
+	int c, cpu_no = 1, span = 250, argc_new = argc, i, no_of_bits = 0;
 	char *benchmark_cmd[BENCHMARK_ARGS], bw_report[64], bm_type[64];
 	char benchmark_cmd_area[BENCHMARK_ARGS][BENCHMARK_ARG_SIZE];
 	int ben_ind, ben_count;
@@ -168,43 +220,17 @@ int main(int argc, char **argv)
 
 	filter_dmesg();
 
-	if (!is_amd && mbm_test) {
-		printf("# Starting MBM BW change ...\n");
-		if (!has_ben)
-			sprintf(benchmark_cmd[5], "%s", "mba");
-		res = mbm_bw_change(span, cpu_no, bw_report, benchmark_cmd);
-		printf("%sok MBM: bw change\n", res ? "not " : "");
-		mbm_test_cleanup();
-		tests_run++;
-	}
+	if (!is_amd && mbm_test)
+		run_mbm_test(has_ben, benchmark_cmd, span, cpu_no, bw_report);
 
-	if (!is_amd && mba_test) {
-		printf("# Starting MBA Schemata change ...\n");
-		if (!has_ben)
-			sprintf(benchmark_cmd[1], "%d", span);
-		res = mba_schemata_change(cpu_no, bw_report, benchmark_cmd);
-		printf("%sok MBA: schemata change\n", res ? "not " : "");
-		mba_test_cleanup();
-		tests_run++;
-	}
+	if (!is_amd && mba_test)
+		run_mba_test(has_ben, benchmark_cmd, span, cpu_no, bw_report);
 
-	if (cmt_test) {
-		printf("# Starting CMT test ...\n");
-		if (!has_ben)
-			sprintf(benchmark_cmd[5], "%s", "cmt");
-		res = cmt_resctrl_val(cpu_no, 5, benchmark_cmd);
-		printf("%sok CMT: test\n", res ? "not " : "");
-		cmt_test_cleanup();
-		tests_run++;
-	}
+	if (cmt_test)
+		run_cmt_test(has_ben, benchmark_cmd, cpu_no);
 
-	if (cat_test) {
-		printf("# Starting CAT test ...\n");
-		res = cat_perf_miss_val(cpu_no, no_of_bits, "L3");
-		printf("%sok CAT: test\n", res ? "not " : "");
-		tests_run++;
-		cat_test_cleanup();
-	}
+	if (cat_test)
+		run_cat_test(cpu_no, no_of_bits);
 
 out:
 	printf("1..%d\n", tests_run);
-- 
2.29.0

[PATCH v3 15/21] selftests/resctrl: Skip the test if requested resctrl feature is not supported

[Fenghua Yu]

There could be two reasons why a resctrl feature might not be enabled on
the platform
1. H/W might not support the feature
2. Even if the H/W supports it, the user might have disabled the feature
   through kernel command line arguments

Hence, any resctrl unit test (like cmt, cat, mbm and mba) before starting
the test will first check if the feature is enabled on the platform or not.
If the feature isn't enabled, then the test returns with an error status.
For example, if MBA isn't supported on a platform and if the user tries to
run MBA, the output will look like this

ok mounting resctrl to "/sys/fs/resctrl"
not ok MBA: schemata change

But, not supporting a feature isn't a test failure. So, instead of treating
it as an error, use the SKIP directive of the TAP protocol. With the
change, the output will look as below

ok MBA # SKIP Hardware does not support MBA or MBA is disabled

Fixes: 01fee6b4d1f9 ("selftests/resctrl: Add MBA test")
Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Fixes: 78941183d1b15 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
Fixes: 790bf585b0eee ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/cat_test.c    |  3 ---
 tools/testing/selftests/resctrl/cmt_test.c    |  3 ---
 tools/testing/selftests/resctrl/mba_test.c    |  3 ---
 tools/testing/selftests/resctrl/mbm_test.c    |  3 ---
 .../testing/selftests/resctrl/resctrl_tests.c | 24 +++++++++++++++++++
 5 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index 1bce84e23783..a18a37ce626c 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -132,9 +132,6 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
 	if (ret)
 		return ret;
 
-	if (!validate_resctrl_feature_request("cat"))
-		return -1;
-
 	/* Get default cbm mask for L3/L2 cache */
 	ret = get_cbm_mask(cache_type);
 	if (ret)
diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index 282ba7fcf17c..119ae65abec7 100644
--- a/tools/testing/selftests/resctrl/cmt_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -122,9 +122,6 @@ int cmt_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
 	if (ret)
 		return ret;
 
-	if (!validate_resctrl_feature_request("cmt"))
-		return -1;
-
 	ret = get_cbm_mask("L3");
 	if (ret)
 		return ret;
diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c
index ba0234d4829e..6f09d46a5424 100644
--- a/tools/testing/selftests/resctrl/mba_test.c
+++ b/tools/testing/selftests/resctrl/mba_test.c
@@ -156,9 +156,6 @@ int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd)
 
 	remove(RESULT_FILE_NAME);
 
-	if (!validate_resctrl_feature_request("mba"))
-		return -1;
-
 	ret = resctrl_val(benchmark_cmd, &param);
 	if (ret)
 		return ret;
diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c
index ca610c3ebc8c..cb3113cb3b10 100644
--- a/tools/testing/selftests/resctrl/mbm_test.c
+++ b/tools/testing/selftests/resctrl/mbm_test.c
@@ -129,9 +129,6 @@ int mbm_bw_change(int span, int cpu_no, char *bw_report, char **benchmark_cmd)
 
 	remove(RESULT_FILE_NAME);
 
-	if (!validate_resctrl_feature_request("mbm"))
-		return -1;
-
 	ret = resctrl_val(benchmark_cmd, &param);
 	if (ret)
 		return ret;
diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index be7cd57efca8..a22dc96c0b43 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -60,6 +60,12 @@ static void run_mbm_test(bool has_ben, char **benchmark_cmd, int span,
 	int res;
 
 	printf("# Starting MBM BW change ...\n");
+
+	if (!validate_resctrl_feature_request("mbm")) {
+		printf("ok MBM # SKIP Hardware does not support MBM or MBM is disabled\n");
+		return;
+	}
+
 	if (!has_ben)
 		sprintf(benchmark_cmd[5], "%s", "mba");
 	res = mbm_bw_change(span, cpu_no, bw_report, benchmark_cmd);
@@ -74,6 +80,12 @@ static void run_mba_test(bool has_ben, char **benchmark_cmd, int span,
 	int res;
 
 	printf("# Starting MBA Schemata change ...\n");
+
+	if (!validate_resctrl_feature_request("mba")) {
+		printf("ok MBA # SKIP Hardware does not support MBA or MBA is disabled\n");
+		return;
+	}
+
 	if (!has_ben)
 		sprintf(benchmark_cmd[1], "%d", span);
 	res = mba_schemata_change(cpu_no, bw_report, benchmark_cmd);
@@ -87,6 +99,12 @@ static void run_cmt_test(bool has_ben, char **benchmark_cmd, int cpu_no)
 	int res;
 
 	printf("# Starting CMT test ...\n");
+
+	if (!validate_resctrl_feature_request("cmt")) {
+		printf("ok CMT # SKIP Hardware does not support CMT or CMT is disabled\n");
+		return;
+	}
+
 	if (!has_ben)
 		sprintf(benchmark_cmd[5], "%s", "cmt");
 	res = cmt_resctrl_val(cpu_no, 5, benchmark_cmd);
@@ -100,6 +118,12 @@ static void run_cat_test(int cpu_no, int no_of_bits)
 	int res;
 
 	printf("# Starting CAT test ...\n");
+
+	if (!validate_resctrl_feature_request("cat")) {
+		printf("ok CAT # SKIP Hardware does not support CAT or CAT is disabled\n");
+		return;
+	}
+
 	res = cat_perf_miss_val(cpu_no, no_of_bits, "L3");
 	printf("%sok CAT: test\n", res ? "not " : "");
 	tests_run++;
-- 
2.29.0

[PATCH v3 16/21] selftests/resctrl: Umount resctrl FS only if mounted

[Fenghua Yu]

umount_resctrlfs() directly attempts to unmount resctrl file system without
checking if resctrl FS is already mounted or not. It returns 0 on success
and on failure it prints an error message and returns an error status.
Calling umount_resctrlfs() when resctrl FS isn't mounted will return an
error status.

There could be situations where-in the caller might not know if resctrl
FS is already mounted or not and the caller might still want to unmount
resctrl FS if it's already mounted (For example during teardown).

To support above use cases, change umount_resctrlfs() such that it now
first checks if resctrl FS is already mounted or not and unmounts resctrl
FS only if it's already mounted.

Fixes: 591a6e8588fc ("selftests/resctrl: Add basic resctrl file system operations and data")
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrlfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 05956319d9ce..21281fd895b7 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -92,6 +92,9 @@ int remount_resctrlfs(bool mum_resctrlfs)
 
 int umount_resctrlfs(void)
 {
+	if (find_resctrl_mount(NULL))
+		return 0;
+
 	if (umount(RESCTRL_PATH)) {
 		perror("# Unable to umount resctrl");
 
-- 
2.29.0

[PATCH v3 17/21] selftests/resctrl: Unmount resctrl FS after running all tests

[Fenghua Yu]

Resctrl test suite is expected to unmount the resctrl file system upon
exit. But there are few scenarios where resctrl test suite might forget to
unmount resctrl FS upon exit. For example, running only mba test on a
Broadwell (BDW) machine (MBA isn't supported on BDW CPU).

This happens because validate_resctrl_feature_request() would mount resctrl
FS to check if mba is enabled on the platform or not and finds that the H/W
doesn't support mba and hence will return false to run_mba_test(). This in
turn makes the main() function return without unmounting resctrl FS.

Fix this by calling umount_resctrlfs() before returning from main()
function, so that the resctrl FS will always be unmounted upon exit.

Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrl_tests.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index a22dc96c0b43..fb66da65b373 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -257,6 +257,7 @@ int main(int argc, char **argv)
 		run_cat_test(cpu_no, no_of_bits);
 
 out:
+	umount_resctrlfs();
 	printf("1..%d\n", tests_run);
 
 	return 0;
-- 
2.29.0

[PATCH v3 18/21] selftests/resctrl: Fix incorrect parsing of iMC counters

[Fenghua Yu]

iMC (Integrated Memory Controller) counters are usually at
"/sys/bus/event_source/devices/" and are named as "uncore_imc_<n>".
num_of_imcs() function tries to count number of such iMC counters so that
it could appropriately initialize required number of perf_attr structures
that could be used to read these iMC counters.

num_of_imcs() function assumes that all the directories under this path
that start with "uncore_imc" are iMC counters. But, on some systems there
could be directories named as "uncore_imc_free_running" which aren't iMC
counters. Trying to read from such directories will result in "not found
file" errors and MBM/MBA tests will fail.

Hence, fix the logic in num_of_imcs() such that it looks at the first
character after "uncore_imc_" to check if it's a numerical digit or not. If
it's a digit then the directory represents an iMC counter, else, skip the
directory.

Fixes: 7f4d257e3a2a ("selftests/resctrl: Add callback to start a benchmark")
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrl_val.c | 22 +++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 270cd95e0026..88f9b641d753 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -221,8 +221,8 @@ static int read_from_imc_dir(char *imc_dir, int count)
  */
 static int num_of_imcs(void)
 {
+	char imc_dir[512], *temp;
 	unsigned int count = 0;
-	char imc_dir[512];
 	struct dirent *ep;
 	int ret;
 	DIR *dp;
@@ -230,7 +230,25 @@ static int num_of_imcs(void)
 	dp = opendir(DYN_PMU_PATH);
 	if (dp) {
 		while ((ep = readdir(dp))) {
-			if (strstr(ep->d_name, UNCORE_IMC)) {
+			temp = strstr(ep->d_name, UNCORE_IMC);
+			if (!temp)
+				continue;
+
+			/*
+			 * imc counters are named as "uncore_imc_<n>", hence
+			 * increment the pointer to point to <n>. Note that
+			 * sizeof(UNCORE_IMC) would count for null character as
+			 * well and hence the last underscore character in
+			 * uncore_imc'_' need not be counted.
+			 */
+			temp = temp + sizeof(UNCORE_IMC);
+
+			/*
+			 * Some directories under "DYN_PMU_PATH" could have
+			 * names like "uncore_imc_free_running", hence, check if
+			 * first character is a numerical digit or not.
+			 */
+			if (temp[0] >= '0' && temp[0] <= '9') {
 				sprintf(imc_dir, "%s/%s/", DYN_PMU_PATH,
 					ep->d_name);
 				ret = read_from_imc_dir(imc_dir, count);
-- 
2.29.0

[PATCH v3 19/21] selftests/resctrl: Fix checking for < 0 for unsigned values

[Fenghua Yu]

Dan reported following static checker warnings

tools/testing/selftests/resctrl/resctrl_val.c:545 measure_vals()
warn: 'bw_imc' unsigned <= 0

tools/testing/selftests/resctrl/resctrl_val.c:549 measure_vals()
warn: 'bw_resc_end' unsigned <= 0

These warnings are reported because
1. measure_vals() declares 'bw_imc' and 'bw_resc_end' as unsigned long
   variables
2. Return value of get_mem_bw_imc() and get_mem_bw_resctrl() are assigned
   to 'bw_imc' and 'bw_resc_end' respectively
3. The returned values are checked for <= 0 to see if the calls failed

Checking for < 0 for an unsigned value doesn't make any sense.

Fix this issue by changing the implementation of get_mem_bw_imc() and
get_mem_bw_resctrl() such that they now accept reference to a variable
and set the variable appropriately upon success and return 0, else return
< 0 on error.

Fixes: 7f4d257e3a2a ("selftests/resctrl: Add callback to start a benchmark")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 tools/testing/selftests/resctrl/resctrl_val.c | 41 +++++++++++--------
 1 file changed, 23 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 88f9b641d753..f723d8534cf2 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -300,9 +300,9 @@ static int initialize_mem_bw_imc(void)
  * Memory B/W utilized by a process on a socket can be calculated using
  * iMC counters. Perf events are used to read these counters.
  *
- * Return: >= 0 on success. < 0 on failure.
+ * Return: = 0 on success. < 0 on failure.
  */
-static float get_mem_bw_imc(int cpu_no, char *bw_report)
+static int get_mem_bw_imc(int cpu_no, char *bw_report, float *bw_imc)
 {
 	float reads, writes, of_mul_read, of_mul_write;
 	int imc, j, ret;
@@ -373,13 +373,18 @@ static float get_mem_bw_imc(int cpu_no, char *bw_report)
 		close(imc_counters_config[imc][WRITE].fd);
 	}
 
-	if (strcmp(bw_report, "reads") == 0)
-		return reads;
+	if (strcmp(bw_report, "reads") == 0) {
+		*bw_imc = reads;
+		return 0;
+	}
 
-	if (strcmp(bw_report, "writes") == 0)
-		return writes;
+	if (strcmp(bw_report, "writes") == 0) {
+		*bw_imc = writes;
+		return 0;
+	}
 
-	return (reads + writes);
+	*bw_imc = reads + writes;
+	return 0;
 }
 
 void set_mbm_path(const char *ctrlgrp, const char *mongrp, int resource_id)
@@ -438,9 +443,8 @@ static void initialize_mem_bw_resctrl(const char *ctrlgrp, const char *mongrp,
  * 1. If con_mon grp is given, then read from it
  * 2. If con_mon grp is not given, then read from root con_mon grp
  */
-static unsigned long get_mem_bw_resctrl(void)
+static int get_mem_bw_resctrl(unsigned long *mbm_total)
 {
-	unsigned long mbm_total = 0;
 	FILE *fp;
 
 	fp = fopen(mbm_total_path, "r");
@@ -449,7 +453,7 @@ static unsigned long get_mem_bw_resctrl(void)
 
 		return -1;
 	}
-	if (fscanf(fp, "%lu", &mbm_total) <= 0) {
+	if (fscanf(fp, "%lu", mbm_total) <= 0) {
 		perror("Could not get mbm local bytes");
 		fclose(fp);
 
@@ -457,7 +461,7 @@ static unsigned long get_mem_bw_resctrl(void)
 	}
 	fclose(fp);
 
-	return mbm_total;
+	return 0;
 }
 
 pid_t bm_pid, ppid;
@@ -549,7 +553,8 @@ static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp,
 static int
 measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start)
 {
-	unsigned long bw_imc, bw_resc, bw_resc_end;
+	unsigned long bw_resc, bw_resc_end;
+	float bw_imc;
 	int ret;
 
 	/*
@@ -559,13 +564,13 @@ measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start)
 	 * Compare the two values to validate resctrl value.
 	 * It takes 1sec to measure the data.
 	 */
-	bw_imc = get_mem_bw_imc(param->cpu_no, param->bw_report);
-	if (bw_imc <= 0)
-		return bw_imc;
+	ret = get_mem_bw_imc(param->cpu_no, param->bw_report, &bw_imc);
+	if (ret < 0)
+		return ret;
 
-	bw_resc_end = get_mem_bw_resctrl();
-	if (bw_resc_end <= 0)
-		return bw_resc_end;
+	ret = get_mem_bw_resctrl(&bw_resc_end);
+	if (ret < 0)
+		return ret;
 
 	bw_resc = (bw_resc_end - *bw_resc_start) / MB;
 	ret = print_results_bw(param->filename, bm_pid, bw_imc, bw_resc);
-- 
2.29.0

[PATCH v3 20/21] selftests/resctrl: Fix unnecessary usage of global variables

[Fenghua Yu]

Reinette reported following compilation issue on Fedora 32, gcc version
10.1.1

/usr/bin/ld: cmt_test.o:<src_dir>/cmt_test.c:22: multiple definition of
`cache_size'; cat_test.o:<src_dir>/cat_test.c:23: first defined here

The same issue is reported for long_mask and count_of_bits variables as
well. Compiler isn't happy because these variables are defined globally in
two .c files namely cmt_test.c and cat_test.c and the compiler during
compilation finds that the variable is already defined (multiple definition
error).

Taking a closer look at the usage of these variables reveals that these
variables are used only locally to cmt_resctrl_val() (defined in
cmt_test.c) and cat_perf_miss_val() (defined in cat_test.c) functions.
These variables are not shared between the two functions. So, there is no
need for these variables to be global. Hence, fix this issue by making
them local variables to the functions where they are used.

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 | 7 ++-----
 tools/testing/selftests/resctrl/cmt_test.c | 6 ++----
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index a18a37ce626c..e518f8f7b4d8 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -17,10 +17,7 @@
 #define MAX_DIFF_PERCENT	4
 #define MAX_DIFF		1000000
 
-int count_of_bits;
 char cbm_mask[256];
-unsigned long long_mask;
-unsigned long cache_size;
 
 /*
  * Change schemata. Write schemata to specified
@@ -121,8 +118,8 @@ void cat_test_cleanup(void)
 
 int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
 {
-	unsigned long l_mask, l_mask_1;
-	int ret, pipefd[2], sibling_cpu_no;
+	unsigned long l_mask, l_mask_1, long_mask, cache_size;
+	int ret, pipefd[2], sibling_cpu_no, count_of_bits;
 	char pipe_message;
 	pid_t bm_pid;
 
diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index 119ae65abec7..f0cb441cca9f 100644
--- a/tools/testing/selftests/resctrl/cmt_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -16,10 +16,7 @@
 #define MAX_DIFF		2000000
 #define MAX_DIFF_PERCENT	15
 
-int count_of_bits;
 char cbm_mask[256];
-unsigned long long_mask;
-unsigned long cache_size;
 
 static int cmt_setup(int num, ...)
 {
@@ -113,7 +110,8 @@ void cmt_test_cleanup(void)
 
 int cmt_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
 {
-	int ret, mum_resctrlfs;
+	int ret, mum_resctrlfs, count_of_bits;
+	unsigned long long_mask, cache_size;
 
 	cache_size = 0;
 	mum_resctrlfs = 1;
-- 
2.29.0

[PATCH v3 21/21] selftests/resctrl: Don't use global variable for capacity bitmask (CBM)

[Fenghua Yu]

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");
-- 
2.29.0

Re: [PATCH v3 00/21] Miscellaneous fixes for resctrl selftests

[Shuah Khan]

On 10/20/20 5:51 PM, Fenghua Yu wrote:
> This patch set has several miscellaneous fixes to resctrl selftest tool
> that are easily visible to user. V1 had fixes to CAT test and CMT test
> but they were dropped in V2 because having them here made the patchset
> humongous. So, changes to CAT test and CMT test will be posted in another
> patchset.
> 

This is still a very long patch series. Several of the patches can be
combined and can be rearranged. 21 patches don't seem to any specific
order.

> Change Log:
> v3:
> Address various comments (commit messages, return value on test failure,
> print failure info on test failure etc) from Reinette and Tony.
> [v2: https://lore.kernel.org/linux-kselftest/cover.1589835155.git.sai.praneeth.prakhya@intel.com/]
> 
> v2:
> 1. Dropped changes to CAT test and CMT test as they will be posted in a later
>     series.
> 2. Added several other fixes
> [v1: https://lore.kernel.org/linux-kselftest/cover.1583657204.git.sai.praneeth.prakhya@intel.com/]
> 
> Fenghua Yu (18):
>    selftests/resctrl: Rename CQM test as CMT test
>    selftests/resctrl: Declare global variables as extern
>    selftests/resctrl: Return if resctrl file system is not supported
>    selftests/resctrl: Check for resctrl mount point only if resctrl FS is
>      supported
>    selftests/resctrl: Use resctrl/info for feature detection
>    selftests/resctrl: Fix missing options "-n" and "-p"
>    selftests/resctrl: Fix MBA/MBM results reporting format
>    selftests/resctrl: Abort running tests if not root user
>    selftests/resctrl: Enable gcc checks to detect buffer overflows
>    selftests/resctrl: Don't hard code value of "no_of_bits" variable

>    selftests/resctrl: Modularize resctrl test suite main() function

Yes. This is a needed change. I didn't make it to this patch yet.

>    selftests/resctrl: Skip the test if requested resctrl feature is not
>      supported

Commented on this patch already. Look into using config file like other
tests.

>    selftests/resctrl: Umount resctrl FS only if mounted
>    selftests/resctrl: Unmount resctrl FS after running all tests
>    selftests/resctrl: Fix incorrect parsing of iMC counters
>    selftests/resctrl: Fix checking for < 0 for unsigned values
>    selftests/resctrl: Fix unnecessary usage of global variables
>    selftests/resctrl: Don't use global variable for capacity bitmask
>      (CBM)
> 
> Reinette Chatre (3):
>    selftests/resctrl: Fix typo
>    selftests/resctrl: Fix typo in help text

Why not combine the above two patches. The commit summary doesn't
make sense.

>    selftests/resctrl: Ensure sibling CPU is not same as original CPU
> 
>   tools/testing/selftests/resctrl/Makefile      |   2 +-
>   tools/testing/selftests/resctrl/README        |   4 +-
>   tools/testing/selftests/resctrl/cache.c       |   4 +-
>   tools/testing/selftests/resctrl/cat_test.c    |  20 +--
>   .../resctrl/{cqm_test.c => cmt_test.c}        |  34 ++--
>   tools/testing/selftests/resctrl/mba_test.c    |  23 ++-
>   tools/testing/selftests/resctrl/mbm_test.c    |  16 +-
>   tools/testing/selftests/resctrl/resctrl.h     |  20 ++-
>   .../testing/selftests/resctrl/resctrl_tests.c | 156 ++++++++++++------
>   tools/testing/selftests/resctrl/resctrl_val.c |  75 ++++++---
>   tools/testing/selftests/resctrl/resctrlfs.c   |  79 ++++++---
>   11 files changed, 272 insertions(+), 161 deletions(-)
>   rename tools/testing/selftests/resctrl/{cqm_test.c => cmt_test.c} (85%)
> 

I will review rest of the patches. Try to combine a few patches and
collapse fixes. I would like to see all the fixes first and then
renaming from CQM to CMT.

thanks,
-- Shuah