[Crash-utility] Incorrect HighMem statistics

[Petr Tesarik]

Hi all,

it seems crash shows incorrect HighMem stats with recent kernels. E.g.:

crash> kmem -i
[...]
TOTAL HIGH  1821682       6.9 GB   93% of TOTAL MEM
 FREE HIGH        0            0    0% of TOTAL HIGH
 TOTAL LOW   132983     519.5 MB    6% of TOTAL MEM
  FREE LOW  1333474       5.1 GB  1002% of TOTAL LOW

BTW note that total low is smaller than free low, which is obviously 
incorrect. I believe that this is somehow related to the Movable zone, because 
the code that counts free low pages checks for pages which belong to 
ZONE_HIGHMEM, which is initialized as:

                vt->ZONE_HIGHMEM = vt->nr_zones - 1;

My system has 4 zones:

ZONE  NAME         SIZE   MEM_MAP  START_PADDR  START_MAPNR
  0   DMA          4080  f4a02200        10000            0
  1   Normal     221694  f4a22000      1000000         4080
  2   HighMem    790002  f50e5fc0     371fe000       225774
  3   Movable         0         0            0            0

And indeed, "help -v" shows:
[...]
    dump_free_pages: dump_free_pages_zones_v2()
[...]
       ZONE_HIGHMEM: 3

I don't know yet how to fix this, but maybe somebody can push me in the right 
direction.

Petr Tesarik
SUSE Linux