lkml.org 
[lkml]   [2010]   [Apr]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: why choose 896MB to the start point of ZONE_HIGHMEM
    On 04/06/2010 12:20 PM, Frank Hu wrote:
    >>
    >> The ELF ABI specifies that user space has 3 GB available to it. That
    >> leaves 1 GB for the kernel. The kernel, by default, uses 128 MB for I/O
    >> mapping, vmalloc, and kmap support, which leaves 896 MB for LOWMEM.
    >>
    >> All of these boundaries are configurable; with PAE enabled the user
    >> space boundary has to be on a 1 GB boundary.
    >>
    >
    > the VM split is also configurable when building the kernel (for 32-bit
    > processors).

    I did say "all these boundaries are configurable". Rather explicitly.

    -hpa


    \
     
     \ /
      Last update: 2010-04-06 21:57    [W:0.020 / U:93.656 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site