當分配大塊數據塊時，囤積性能嚴重下降

我在'C'中寫了一個動態內存密集型的示例程序，並試圖對'glibc'默認分配器和Hoard分配器進行基準測試（就時間而言）。當分配大塊數據塊時，囤積性能嚴重下降

1 #include <stdio.h> 
    2 #include <stdlib.h> 
    3 
    4 #define NUM_OF_BLOCKS (1 * 4096) 
    5 
    6 void *allocated_mem_ptr_arr[NUM_OF_BLOCKS]; 
    7 
    8 int 
    9 main (int argc, char *argv[]) 
10 { 
11  void *myblock = NULL; 
12 
13  int count, iter; 
14 
15  int blk_sz; 
16 
17  if (argc != 2) 
18  { 
19   fprintf (stderr, "Usage:./memory_intensive <Block size (KB)>\n\n"); 
20   exit (-1); 
21  } 
22 
23  blk_sz = atoi (argv[1]); 
24 
25  for (iter = 0; iter < 1024; iter++) 
26  { 
27   /* 
28   * The allocated memory is not accessed (read/write) hence the residual memory 
29   * size remains low since no corresponding physical pages are being allocated 
30   */ 
31   printf ("\nCurrently at iteration %d\n", iter); 
32   fflush (NULL); 
33 
34   for (count = 0; count < NUM_OF_BLOCKS; count++) 
35   { 
36    myblock = (void *) malloc (blk_sz * 1024); 
37    if (!myblock) 
38    { 
39     printf ("malloc() fails\n"); 
40     sleep (30); 
41     return; 
42    } 
43 
44    allocated_mem_ptr_arr[count] = myblock; 
45   } 
46 
47   for (count = 0; count < NUM_OF_BLOCKS; count++) 
48   { 
49    free (allocated_mem_ptr_arr[count]); 
50   } 
51  } 
52 }

由於這個基準活動的結果，我得到了下面的結果（塊大小，所經歷的時間爲默認的分配，所經歷的時間爲囤積居奇）：