lkml.org 
[lkml]   [2005]   [May]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] Factor in buddy allocator alignment requirements in node memory alignment


    --On Monday, May 16, 2005 12:43:17 -0700 christoph <christoph@scalex86.org> wrote:

    > On Mon, 16 May 2005, Dave Hansen wrote:
    >
    >> On Mon, 2005-05-16 at 12:05 -0700, christoph wrote:
    >> > Memory for nodes on i386 is currently aligned on 2 MB boundaries.
    >> > However, the buddy allocator needs pages to be aligned on
    >> > PAGE_SIZE << MAX_ORDER which is 8MB if MAX_ORDER = 11.
    >>
    >> Why do you need this? Are you planning on allowing NUMA KVA remap pages
    >> to be handed over to the buddy allocator? That would be a major
    >> departure from what we do now, and I'd be very interested in seeing how
    >> that is implemented before a infrastructure for it goes in.
    >
    > Because the buddy allocator is complaining about wrongly allocated zones!
    >
    > in page_alloc.c:
    >
    > static void __init free_area_init_core(struct pglist_data *pgdat,
    > unsigned long *zones_size, unsigned long *zholes_size)
    > {
    > ...
    >
    > const unsigned long zone_required_alignment = 1UL << (MAX_ORDER-1);
    >
    > ...
    >
    > if ((zone_start_pfn) & (zone_required_alignment-1))
    > printk(KERN_CRIT "BUG: wrong zone alignment, it will crash\n");

    IIRC, we decided that warning was worthless ... and I *think* Andy fixed
    it to do non-aligned zones, though it might have been someone else. Andy,
    can you remember what you did to fix this up?

    M.


    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-05-16 22:57    [W:0.020 / U:61.440 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site