Allocates memory and trigger pgscan activity

memflood.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>

void allocate_memory(size_t gb)
{
	size_t bytes = gb * 1024 * 1024 * 1024ULL;
	size_t pgsize = sysconf(_SC_PAGESIZE);
	unsigned char *ptr = malloc(bytes);

	if (!ptr) {
		puts("Memory allocation failed");
		exit(1);
	}

	// Continuously write the memory to trigger pgscan activity
	while (1) {
		static int once = 0;

		for (size_t i = 0; i < bytes; i += pgsize)
			ptr[i] = 0xff;

		if (!once) {
			printf("Allocated %zu GB. Press Ctrl+C to exit.\n", gb);
			once = 1;
		}

		sleep(1);
	}
}

int main(int argc, char *argv[])
{
	if (argc != 2) {
		printf("Usage: %s <gb>\n", argv[0]);
		return 1;
	}

	int gb = atoi(argv[1]);
	if (gb <= 0) {
		puts("Please provide a positive integer for GB.");
		return 1;
	}

	allocate_memory(gb);
	return 0;
}