An example of a small custom memory allocator that contiguously allocates space for a linkedlist to prevent excessive jumps. Please don't use this code. There's several ways this can be improved.

linkedlist_contingous_alloc.c

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

// 16 byte struct
typedef struct Node {
  int64_t value;
  struct Node* next;
} Node;

// A linked list allocator of 'count' objects.
typedef struct Alloc {
  void* head;
  uint64_t count;
} Alloc;

// Initializes the allocator for count nodes
void init_alloc(Alloc* alloc, uint64_t count) {
  void* head = malloc(sizeof(Node) * count);
  alloc->head = head;
  alloc->count = 0;
}

void insert_value(Alloc* alloc, uint64_t value) {
  Node* pointer_to_insert_at = (Node*) alloc->head + alloc->count;
  pointer_to_insert_at->value = value;
  
  alloc->count++;
}

void print_values(Alloc* alloc) {
  for (int i = 0; i < alloc->count; ++i) {
    Node* n = (Node*) alloc->head + i;
    printf("Node #%d: %lld\n", i, n->value);
  }
}

// cleanup
void destroy_alloc(Alloc* alloc) {
  free(alloc->head);
}

int main() {
  const uint64_t num_nodes_to_alloc = 1000;

  Alloc alloc;
  init_alloc(&alloc, num_nodes_to_alloc);

  for (int i = 0; i < num_nodes_to_alloc; i++) insert_value(&alloc, i);

  print_values(&alloc);

  destroy_alloc(&alloc);
}