• Paul Mundt's avatar
    NOMMU: Make mmap allocation page trimming behaviour configurable. · dd8632a1
    Paul Mundt authored
    NOMMU mmap allocates a piece of memory for an mmap that's rounded up in size to
    the nearest power-of-2 number of pages.  Currently it then discards the excess
    pages back to the page allocator, making that memory available for use by other
    things.  This can, however, cause greater amount of fragmentation.
    To counter this, a sysctl is added in order to fine-tune the trimming
    behaviour.  The default behaviour remains to trim pages aggressively, while
    this can either be disabled completely or set to a higher page-granular
    watermark in order to have finer-grained control.
    vm region vm_top bits taken from an earlier patch by David Howells.
    Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
    Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
    Tested-by: default avatarMike Frysinger <vapier.adi@gmail.com>
nommu-mmap.txt 11.2 KB