title: unevictable page
body: <p>I getting a kernel crash as below. Here I can observe large memory is present in unevictablle page.
  I wish to know when exactly memory is added to unevictable page list.</p>
  
  <p>Also, from the below message I can understand only 1724kB  is available in the system.
  is it correct?</p>
  
  <pre><code>kswapd0: page allocation failure. order:0, mode:0xd0
  [&lt;c002aed4&gt;] (unwind_backtrace+0x0/0xdc) from [&lt;c006d5b0&gt;] (__alloc_pages_nodemask+0x490/0x4ec)
  [&lt;c006d5b0&gt;] (__alloc_pages_nodemask+0x490/0x4ec) from [&lt;c008416c&gt;] (cache_alloc_refill+0x260/0x4f4)
  [&lt;c008416c&gt;] (cache_alloc_refill+0x260/0x4f4) from [&lt;c0084498&gt;] (__kmalloc+0x98/0xd8)
  [&lt;c0084498&gt;] (__kmalloc+0x98/0xd8) from [&lt;c01f73d8&gt;] (__alloc_skb+0x44/0x124)
  [&lt;c01f73d8&gt;] (__alloc_skb+0x44/0x124) from [&lt;c01f7cac&gt;] (skb_copy+0x2c/0xa0)
  Exception stack(0xc4ecbdf0 to 0xc4ecbe38)
  bde0:                                     00000000 00000064 c0347718 00000000 
  be00: 00000001 00000000 c0347718 c0347718 c4ecbf54 00000000 00000000 000000fd 
  be20: c4ecbf00 c4ecbe38 c00724b4 c00724c4 80000013 ffffffff                   
  [&lt;c0024b18&gt;] (__irq_svc+0x38/0xc0) from [&lt;c00724c4&gt;] (shrink_zone+0x88/0x70c)
  [&lt;c00724c4&gt;] (shrink_zone+0x88/0x70c) from [&lt;c0072ff4&gt;] (kswapd+0x34c/0x4d8)
  [&lt;c0072ff4&gt;] (kswapd+0x34c/0x4d8) from [&lt;c004dcec&gt;] (kthread+0x7c/0x84)
  [&lt;c004dcec&gt;] (kthread+0x7c/0x84) from [&lt;c0025ed0&gt;] (kernel_thread_exit+0x0/0x8)
  Mem-info:
  Normal per-cpu:
  CPU    0: hi:   42, btch:   7 usd:  36
  Active_anon:124 active_file:0 inactive_anon:129
   inactive_file:0 unevictable:8111 dirty:0 writeback:0 unstable:0
   free:431 slab:19526 mapped:408 pagetables:53 bounce:0
  Normal free:1724kB min:1396kB low:1744kB high:2092kB active_anon:496kB inactive_anon:516kB active_file:0kB inactive_file:0kB unevictable:32444kB present:121920kB pages_scanned:0 all_unreclaimable? no
  lowmem_reserve[]: 0 0
  Normal: 103*4kB 34*8kB 3*16kB 3*32kB 2*64kB 0*128kB 1*256kB 1*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 1724kB
  8114 total pagecache pages
  30720 pages of RAM
  547 free pages
  1204 reserved pages
  19526 slab pages
  1662 pages shared
  0 pages swap cached
  </code></pre>