memory.c

   1 /*
   2  * Memory helpers
   3  */
   4 #include <unistd.h>
   5 #include <sys/shm.h>
   6 #include <sys/mman.h>
   7
   8 #include "fio.h"
   9 #include "os.h"
  10
  11 static void *pinned_mem;
  12
  13 void fio_unpin_memory(void)
  14 {
  15         if (pinned_mem) {
  16                 if (munlock(pinned_mem, mlock_size) < 0)
  17                         perror("munlock");
  18                 munmap(pinned_mem, mlock_size);
  19                 pinned_mem = NULL;
  20         }
  21 }
  22
  23 int fio_pin_memory(void)
  24 {
  25         unsigned long long phys_mem;
  26
  27         if (!mlock_size)
  28                 return 0;
  29
  30         /*
  31          * Don't allow mlock of more than real_mem-128MB
  32          */
  33         phys_mem = os_phys_mem();
  34         if (phys_mem) {
  35                 if ((mlock_size + 128 * 1024 * 1024) > phys_mem) {
  36                         mlock_size = phys_mem - 128 * 1024 * 1024;
  37                         fprintf(f_out, "fio: limiting mlocked memory to %lluMiB\n", mlock_size >> 20);
  38                 }
  39         }
  40
  41         pinned_mem = mmap(NULL, mlock_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | OS_MAP_ANON, 0, 0);
  42         if (pinned_mem == MAP_FAILED) {
  43                 perror("malloc locked mem");
  44                 pinned_mem = NULL;
  45                 return 1;
  46         }
  47         if (mlock(pinned_mem, mlock_size) < 0) {
  48                 perror("mlock");
  49                 munmap(pinned_mem, mlock_size);
  50                 pinned_mem = NULL;
  51                 return 1;
  52         }
  53
  54         return 0;
  55 }
  56
  57 /*
  58  * Setup the buffer area we need for io.
  59  */
  60 int allocate_io_mem(struct thread_data *td)
  61 {
  62         if (td->mem_type == MEM_MALLOC)
  63                 td->orig_buffer = malloc(td->orig_buffer_size);
  64         else if (td->mem_type == MEM_SHM || td->mem_type == MEM_SHMHUGE) {
  65                 int flags = IPC_CREAT | SHM_R | SHM_W;
  66
  67                 if (td->mem_type == MEM_SHMHUGE)
  68                         flags |= SHM_HUGETLB;
  69
  70                 td->shm_id = shmget(IPC_PRIVATE, td->orig_buffer_size, flags);
  71                 if (td->shm_id < 0) {
  72                         td_verror(td, errno);
  73                         perror("shmget");
  74                         return 1;
  75                 }
  76
  77                 td->orig_buffer = shmat(td->shm_id, NULL, 0);
  78                 if (td->orig_buffer == (void *) -1) {
  79                         td_verror(td, errno);
  80                         perror("shmat");
  81                         td->orig_buffer = NULL;
  82                         return 1;
  83                 }
  84         } else if (td->mem_type == MEM_MMAP || td->mem_type == MEM_MMAPHUGE) {
  85                 int flags = MAP_PRIVATE;
  86
  87                 td->mmapfd = 0;
  88
  89                 if (td->mmapfile) {
  90                         td->mmapfd = open(td->mmapfile, O_RDWR|O_CREAT, 0644);
  91
  92                         if (td->mmapfd < 0) {
  93                                 td_verror(td, errno);
  94                                 perror("open mmap file");
  95                                 td->orig_buffer = NULL;
  96                                 return 1;
  97                         }
  98                 } else
  99                         flags |= OS_MAP_ANON;
 100
 101                 td->orig_buffer = mmap(NULL, td->orig_buffer_size, PROT_READ | PROT_WRITE, flags, td->mmapfd, 0);
 102                 if (td->orig_buffer == MAP_FAILED) {
 103                         td_verror(td, errno);
 104                         perror("mmap");
 105                         td->orig_buffer = NULL;
 106                         if (td->mmapfd) {
 107                                 close(td->mmapfd);
 108                                 unlink(td->mmapfile);
 109                         }
 110
 111                         return 1;
 112                 }
 113         }
 114
 115         return 0;
 116 }
 117
 118 void free_io_mem(struct thread_data *td)
 119 {
 120         if (td->mem_type == MEM_MALLOC)
 121                 free(td->orig_buffer);
 122         else if (td->mem_type == MEM_SHM || td->mem_type == MEM_SHMHUGE) {
 123                 struct shmid_ds sbuf;
 124
 125                 shmdt(td->orig_buffer);
 126                 shmctl(td->shm_id, IPC_RMID, &sbuf);
 127         } else if (td->mem_type == MEM_MMAP || td->mem_type == MEM_MMAPHUGE) {
 128                 munmap(td->orig_buffer, td->orig_buffer_size);
 129                 if (td->mmapfile) {
 130                         close(td->mmapfd);
 131                         unlink(td->mmapfile);
 132                         free(td->mmapfile);
 133                 }
 134         } else
 135                 log_err("Bad memory type %u\n", td->mem_type);
 136
 137         td->orig_buffer = NULL;
 138 }