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                         log_info("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->o.mem_type == MEM_MALLOC)
  63                 td->orig_buffer = malloc(td->orig_buffer_size);
  64         else if (td->o.mem_type == MEM_SHM || td->o.mem_type == MEM_SHMHUGE) {
  65                 int flags = IPC_CREAT | SHM_R | SHM_W;
  66
  67                 if (td->o.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, "shmget");
  73                         if (geteuid() != 0 && errno == ENOMEM)
  74                                 log_err("fio: you may need to run this job as root\n");
  75
  76                         return 1;
  77                 }
  78
  79                 td->orig_buffer = shmat(td->shm_id, NULL, 0);
  80                 if (td->orig_buffer == (void *) -1) {
  81                         td_verror(td, errno, "shmat");
  82                         td->orig_buffer = NULL;
  83                         return 1;
  84                 }
  85         } else if (td->o.mem_type == MEM_MMAP ||
  86                    td->o.mem_type == MEM_MMAPHUGE) {
  87                 int flags = MAP_PRIVATE;
  88
  89                 td->mmapfd = 0;
  90
  91                 if (td->mmapfile) {
  92                         td->mmapfd = open(td->mmapfile, O_RDWR|O_CREAT, 0644);
  93
  94                         if (td->mmapfd < 0) {
  95                                 td_verror(td, errno, "open mmap file");
  96                                 td->orig_buffer = NULL;
  97                                 return 1;
  98                         }
  99                         if (ftruncate(td->mmapfd, td->orig_buffer_size) < 0) {
 100                                 td_verror(td, errno, "truncate mmap file");
 101                                 td->orig_buffer = NULL;
 102                                 return 1;
 103                         }
 104                 } else
 105                         flags |= OS_MAP_ANON;
 106
 107                 td->orig_buffer = mmap(NULL, td->orig_buffer_size, PROT_READ | PROT_WRITE, flags, td->mmapfd, 0);
 108                 if (td->orig_buffer == MAP_FAILED) {
 109                         td_verror(td, errno, "mmap");
 110                         td->orig_buffer = NULL;
 111                         if (td->mmapfd) {
 112                                 close(td->mmapfd);
 113                                 unlink(td->mmapfile);
 114                         }
 115
 116                         return 1;
 117                 }
 118         }
 119
 120         return 0;
 121 }
 122
 123 void free_io_mem(struct thread_data *td)
 124 {
 125         if (td->o.mem_type == MEM_MALLOC)
 126                 free(td->orig_buffer);
 127         else if (td->o.mem_type == MEM_SHM || td->o.mem_type == MEM_SHMHUGE) {
 128                 struct shmid_ds sbuf;
 129
 130                 shmdt(td->orig_buffer);
 131                 shmctl(td->shm_id, IPC_RMID, &sbuf);
 132         } else if (td->o.mem_type == MEM_MMAP ||
 133                    td->o.mem_type == MEM_MMAPHUGE) {
 134                 munmap(td->orig_buffer, td->orig_buffer_size);
 135                 if (td->mmapfile) {
 136                         close(td->mmapfd);
 137                         unlink(td->mmapfile);
 138                         free(td->mmapfile);
 139                 }
 140         } else
 141                 log_err("Bad memory type %u\n", td->o.mem_type);
 142
 143         td->orig_buffer = NULL;
 144 }