• David Gibson's avatar
    [PATCH] Dynamic hugepage addresses for ppc64 · c594adad
    David Gibson authored
    Paulus, I think this is now a reasonable candidate for the post-2.6.13
    queue.
    
    Relax address restrictions for hugepages on ppc64
    
    Presently, 64-bit applications on ppc64 may only use hugepages in the
    address region from 1-1.5T.  Furthermore, if hugepages are enabled in
    the kernel config, they may only use hugepages and never normal pages
    in this area.  This patch relaxes this restriction, allowing any
    address to be used with hugepages, but with a 1TB granularity.  That
    is if you map a hugepage anywhere in the region 1TB-2TB, that entire
    area will be reserved exclusively for hugepages for the remainder of
    the process's lifetime.  This works analagously to hugepages in 32-bit
    applications, where hugepages can be mapped anywhere, but with 256MB
    (mmu segment) granularity.
    
    This patch applies on top of the four level pagetable patch
    (http://patchwork.ozlabs.org/linuxppc64/patch?id=1936).
    Signed-off-by: default avatarDavid Gibson <dwg@au1.ibm.com>
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    c594adad
hugetlbpage.c 18 KB