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:0.054 / U:0.544 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site