From bdb8350f1b0b834649c057f00cd77abb5fb92778 Mon Sep 17 00:00:00 2001
From: John Kacur <jkacur@redhat.com>
Date: Fri, 19 Feb 2021 13:18:27 -0500
Subject: [PATCH] Revert "cyclictest: Use affinity_mask for steering thread
 placement"

This reverts commit 8305e65092deeaf900366c6250d4b319f6c274b6.

Reverting to put back the code that allows us to run on machines
without libnuma.

However, there were some ideas in this patch that were not directly
related to that and could be revisited.

Signed-off-by: John Kacur <jkacur@redhat.com>
---
 src/cyclictest/cyclictest.c | 38 ++++++++++++++++++++++++++++++-------
 1 file changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index c3d45f3..e2753db 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -892,6 +892,7 @@ static int interval = DEFAULT_INTERVAL;
 static int distance = -1;
 static struct bitmask *affinity_mask = NULL;
 static int smp = 0;
+static int setaffinity = AFFINITY_UNSPECIFIED;
 
 static int clocksources[] = {
 	CLOCK_MONOTONIC,
@@ -1019,12 +1020,22 @@ static void process_options(int argc, char *argv[], int max_cpus)
 				break;
 			if (optarg) {
 				parse_cpumask(optarg, max_cpus, &affinity_mask);
+				setaffinity = AFFINITY_SPECIFIED;
 			} else if (optind < argc &&
 				   (atoi(argv[optind]) ||
 				    argv[optind][0] == '0' ||
 				    argv[optind][0] == '!')) {
 				parse_cpumask(argv[optind], max_cpus, &affinity_mask);
+				setaffinity = AFFINITY_SPECIFIED;
+			} else {
+				setaffinity = AFFINITY_USEALL;
 			}
+
+			if (setaffinity == AFFINITY_SPECIFIED && !affinity_mask)
+				display_help(1);
+			if (verbose)
+				printf("Using %u cpus.\n",
+					numa_bitmask_weight(affinity_mask));
 			break;
 		case 'A':
 		case OPT_ALIGNED:
@@ -1117,6 +1128,7 @@ static void process_options(int argc, char *argv[], int max_cpus)
 		case OPT_SMP: /* SMP testing */
 			smp = 1;
 			num_threads = -1; /* update after parsing */
+			setaffinity = AFFINITY_USEALL;
 			break;
 		case 't':
 		case OPT_THREADS:
@@ -1185,16 +1197,23 @@ static void process_options(int argc, char *argv[], int max_cpus)
 		use_nanosleep = MODE_CLOCK_NANOSLEEP;
 	}
 
+	/* if smp wasn't requested, test for numa automatically */
+	if (!smp) {
+		if (setaffinity == AFFINITY_UNSPECIFIED)
+			setaffinity = AFFINITY_USEALL;
+	}
+
 	if (option_affinity && smp) {
 		warn("-a ignored due to smp mode\n");
 		if (affinity_mask) {
 			numa_bitmask_free(affinity_mask);
 			affinity_mask = NULL;
 		}
+		setaffinity = AFFINITY_USEALL;
 	}
 
 	if (smi) {
-		if (affinity_mask)
+		if (setaffinity == AFFINITY_UNSPECIFIED)
 			fatal("SMI counter relies on thread affinity\n");
 
 		if (!has_smi_counter())
@@ -1777,7 +1796,7 @@ int main(int argc, char **argv)
 	}
 
 	/* Restrict the main pid to the affinity specified by the user */
-	if (affinity_mask) {
+	if (affinity_mask != NULL) {
 		int res;
 
 		errno = 0;
@@ -1940,13 +1959,18 @@ int main(int argc, char **argv)
 		if (status != 0)
 			fatal("error from pthread_attr_init for thread %d: %s\n", i, strerror(status));
 
-		if (affinity_mask)
+		switch (setaffinity) {
+		case AFFINITY_UNSPECIFIED: cpu = -1; break;
+		case AFFINITY_SPECIFIED:
 			cpu = cpu_for_thread_sp(i, max_cpus, affinity_mask);
-		else
+			if (verbose)
+				printf("Thread %d using cpu %d.\n", i, cpu);
+			break;
+		case AFFINITY_USEALL:
 			cpu = cpu_for_thread_ua(i, max_cpus);
-
-		if (verbose)
-			printf("Thread %d using cpu %d.\n", i, cpu);
+			break;
+		default: cpu = -1;
+		}
 
 		/* find the memory node associated with the cpu i */
 		node = rt_numa_numa_node_of_cpu(cpu);