2010-03-15 18:17:37     Question about kernel's memory map

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2010-03-15 18:17:37     Question about kernel's memory map

Ross Squires (UNITED STATES)

Message: 87219   


During the boot process, the kernel outputs the following map on the BF548 EZKIT:


Memory map:

  fixedcode = 0x00000400-0x00000490

  text      = 0x00001000-0x001a6bb0

  rodata    = 0x001a6bb0-0x002355bc

  bss       = 0x00236000-0x0024da90

  data      = 0x0024da90-0x0026c000

    stack   = 0x0026a000-0x0026c000

  init      = 0x0026c000-0x00298000

  available = 0x00298000-0x03dff000

  DMA Zone  = 0x03e00000-0x04000000


Am I correct in thinking that the "available" memory is what correlates to the "total" memory reported by the free command?


              total         used         free       shared      buffers

  Mem:        60432         6940        53492            0          140


If so, then by my math  the memory addresses 0x00298000 to 0x03dff000 should make 60828kb of total memory, instead of 60432kb. Are my estimates correct? What am I missing?




2010-03-15 19:09:39     Re: Question about kernel's memory map

Mike Frysinger (UNITED STATES)

Message: 87221   


the memory map is the raw setup from the arch to the common code  what the common code (memory allocator) decides to do with things has no absolute bearings on the memory map.


for example, the available region includes reserved pages which are not included in the total field.