title: how to determine the available physical memory in linux
body: <p>I'm trying to figure if my software running on <code>linux suffers from memory leak</code>. I've tried to measure the available physical memory as found in <code>/proc/meminfo</code> (see below) but could understand which field(s) represents the available memory and what is the relation between <code>MemFree, Cached, Buffers, Active, Inactive</code>.</p>
  
  <pre><code>cat /proc/meminfo
  MemTotal:       124128 kB
  MemFree:         62872 kB
  Buffers:             0 kB
  Cached:          15624 kB
  SwapCached:          0 kB
  Active:          38724 kB
  Inactive:        11148 kB
  SwapTotal:           0 kB
  SwapFree:            0 kB
  Dirty:               0 kB
  Writeback:           0 kB
  AnonPages:       34272 kB
  Mapped:          14640 kB
  Slab:             5564 kB
  SReclaimable:      424 kB
  SUnreclaim:       5140 kB
  PageTables:        504 kB
  NFS_Unstable:        0 kB
  Bounce:              0 kB
  WritebackTmp:        0 kB
  CommitLimit:     62064 kB
  Committed_AS:    57936 kB
  VmallocTotal:   655360 kB
  VmallocUsed:      1016 kB
  VmallocChunk:   654328 kB 
  </code></pre>