title: Max possible shared memory size in 64-bit Linux machine
body: <p>I have 64-bit Linux machine(Intel Xeon L5410 @ 2.33GHz). </p>
  
  <pre><code>**meminfo:**
  MemTotal:     24672736 kB 
  MemFree:        145372 kB 
  Buffers:        181896 kB 
  Cached:       22004648 kB 
  SwapCached:     195072 kB 
  Active:        9761028 kB 
  Inactive:     13964532 kB 
  HighTotal:           0 kB 
  HighFree:            0 kB 
  LowTotal:     24672736 kB 
  LowFree:        145372 kB 
  SwapTotal:    17414452 kB 
  SwapFree:     15618852 kB 
  Dirty:         2125148 kB 
  Writeback:           0 kB 
  AnonPages:     1358396 kB 
  Mapped:        1069632 kB 
  Slab:           699464 kB 
  CommitLimit:  29750820 kB 
  Committed_AS:  9236252 kB 
  PageTables:      38620 kB 
  VmallocTotal: 34359738367 kB 
  VmallocUsed:     17272 kB 
  VmallocChunk: 34359718843 kB 
  HugePages_Total:     0 
  HugePages_Free:      0 
  HugePages_Rsvd:      0 
  Hugepagesize:     2048 kB 
  
  **Also the shm details are:**
  shmall                2097152 
  shmmax                3294967296 
  shmmni                4096 
  </code></pre>
  
  <p>I am trying to create shared memory above 2 GB, shmget is successful but later core dump occurs with the error that cannot access memory.
  While shared memory below 2GB works perfectly fine.
  I am able to find any valid reason for this as my shmmax value is around 3GB</p>