Move other tools to tools/

tools/memtool.c

@@ -0,0 +1,214 @@
+/* Copyright (c) 2024 Barcelona Supercomputing Center (BSC)
+ * SPDX-License-Identifier: MIT
+ * Author: Rodrigo Arias Mallo <rodrigo.arias@bsc.es> */
+
+/* This is just a small tool to exercise the memory which attempts to
+ * stress the virtual memory, in a crude attempt to reproduce the hangs
+ * that we were observing while booting NixOS. */
+
+/* Changelog:
+ *   v0.0.1 (2024-07-10): Start version with "chain" and "fill" tests.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+
+#define MAX_SIZE (1024L * 1024L)
+
+struct block {
+	struct block *next;
+	size_t size;
+	uint32_t data[];
+};
+
+struct chain {
+	struct block *front;
+	struct block *tail;
+	long maxsize;
+	long nbytes;
+	long nblocks;
+};
+
+static int
+allocate(struct chain *chain)
+{
+	/* Constraint the number of elements based on the maxsize */
+	long maxn = chain->maxsize / sizeof(uint32_t);
+	long n = (long) rand() % maxn;
+
+	size_t size = sizeof(struct block) + n * sizeof(uint32_t);
+
+	printf("allocating...\n");
+
+	struct block *b = malloc(size);
+
+	/* No mem */
+	if (b == NULL)
+		return -1;
+
+	b->size = size;
+	b->next = NULL;
+
+	/* Populate the block with some data */
+	printf("filling...\n");
+	for (long i = 0; i < n; i++)
+		b->data[i] = rand();
+
+	/* Add it to the chain */
+	if (chain->tail)
+		chain->tail->next = b;
+
+	chain->tail = b;
+
+	/* And to the front if it is the first */
+	if (!chain->front)
+		chain->front = b;
+
+	chain->nblocks++;
+	chain->nbytes += size;
+
+	return 0;
+}
+
+static int
+deallocate(struct chain *chain)
+{
+	/* May run out of blocks */
+	if (!chain->front)
+		return -1;
+
+	struct block *b = chain->front;
+
+	chain->front = b->next;
+
+	/* Last block */
+	if (chain->tail == b)
+		chain->tail = NULL;
+
+	chain->nblocks--;
+	chain->nbytes -= b->size;
+
+	printf("deallocating...\n");
+	free(b);
+
+	return 0;
+}
+
+static void
+do_chain(int argc, char *argv[])
+{
+	struct chain chain = {0};
+
+	/* Default 1 MiB */
+	chain.maxsize = 1024L * 1024L;
+
+	if (argc > 0)
+		chain.maxsize = atol(argv[0]);
+
+	printf("mode chain: maxsize=%ldK\n", chain.maxsize / 1024);
+
+	srand(123);
+
+	for (long iter = 0; ; iter++) {
+		int p = rand() % 100;
+		int is_alloc = (p > 10);
+		int ret = 0;
+		char c;
+		if (is_alloc) {
+			if (allocate(&chain) == 0)
+				c = 'A';
+			else
+				c = '-';
+		} else {
+			if (deallocate(&chain) == 0)
+				c = 'D';
+			else
+				c = '-';
+		}
+
+		printf("iter=%ld nblocks=%ld allocated=%ldK (%c)\n",
+				iter, chain.nblocks, chain.nbytes / 1024,
+				c);
+	}
+}
+
+static void
+do_fill(int argc, char *argv[])
+{
+	/* Default: 256 MiB */
+	long nbytes = 256L * 1024L * 1024L;
+
+	if (argc > 0)
+		nbytes = atol(argv[0]);
+
+	long n = nbytes / sizeof(int);
+
+	printf("mode fill: nbytes=%ldM, n=%ld\n",
+			nbytes / (1024L * 1024L), n);
+
+	int *buf = malloc(nbytes);
+
+	if (!buf) {
+		perror("malloc failed");
+		exit(1);
+	}
+
+	for (long i = 0; i < n; i++) {
+		buf[i] = i;
+		if ((i % (1024L * 1024L)) == 0)
+			printf("written=%ldK, addr=%p OK\n",
+					i * sizeof(int) / 1024L,
+					&buf[i]);
+	}
+
+	free(buf);
+
+	printf("fill test OK\n");
+}
+
+static void
+usage(void)
+{
+	printf(
+"Usage: memtool <command> [<options>...]\n"
+"\n"
+"Available commands:\n"
+"  chain [<maxsize>]\n"
+"        Creates a chain of blocks of random size, each up to maxsize\n"
+"        or 1MiB if not given. Blocks are freed with 10% probability\n"
+"        starting from the oldest.\n"
+"\n"
+"  fill [<size>]\n"
+"        Allocates a vector of the given size (or 256 MiB if not given)\n"
+"        and initializes it with a increasing value per element.\n"
+"\n");
+
+	exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+	printf("memtool v0.0.1 - Rodrigo Arias Mallo <rodrigo.arias@bsc.es>\n");
+
+	if (argc < 2)
+		usage();
+
+	/* Skip program name */
+	argc--; argv++;
+
+	const char *mode = argv[0];
+
+	/* Skip mode */
+	argc--; argv++;
+
+	if (strcmp(mode, "chain") == 0)
+		do_chain(argc, argv);
+	else if (strcmp(mode, "fill") == 0)
+		do_fill(argc, argv);
+	else
+		usage();
+
+	return 0;
+}