lkml.org 
[lkml]   [2006]   [Dec]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH] Fix sparsemem on Cell
    From
    Date

    > The only other assumption is that all memory-hotplug-time pages
    > given to memmap_init_zone() are valid and able to be onlined into
    > any any zone after the system is running. The "valid" part is
    > really just a question of whether or not a 'struct page' is there
    > for the pfn, and *not* whether there is actual memory. Since
    > all sparsemem sections have contiguous mem_map[]s within them,
    > and we only memory hotplug entire sparsemem sections, we can
    > be confident that this assumption will hold.
    >
    > As for the memory being in the right node, we'll assume tha
    > memory hotplug is putting things in the right node.

    BTW, just that people know, what we are adding isn't even memory :-) We
    are calling __add_pages() to create struct page for the SPE local stores
    and register space as we use them later from a nopage() handler (and no,
    we can't use no_pfn just yet for various reasons, notably we need to
    handle races with unmap_mapping_ranges() and thus have the truncate
    logic in).

    Those pages, thus, must never be onlined. Ever. It might make sense to
    create a way to inform memory hotplug of that fact, but on the other
    hand, I wouldn't bother as I have a plan to get rid of those
    __add_pages() completely and work without struct page, maybe in a 2.6.21
    timeframe.

    Ben.


    -
    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: 2006-12-15 21:29    [W:0.024 / U:61.724 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site