--On Thursday, September 06, 2001 12:07 PM -0300 Rik van Riel
<riel@conectiva.com.br> wrote:
> On many systems, higher-order allocations are a really really
> small fraction of the allocations, so ideally we'd have them
> take the burden of memory fragmentation and won't punish the
> normal allocations.
The only nit being, every instance Stephan's reported so far,
and in most other reports I've seen, the allocation
has been GFP_ATOMIC (i.e. with mask without __GFP_WAIT).
For non-atomic >0 order allocations we already have some
good logic that does (b) via page_launder(), and
where necessary reclaim_page(),__free_page().
So waiting until we are in the high order allocation
allocation is too late, as we don't have room to move.
I think we need to defragment / avoid fragmentation
BEFORE the GFP_ATOMIC high order allocation comes along.
I have some ideas I'd like to test tonight.
-- Alex Bligh - 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/
This archive was generated by hypermail 2b29 : Fri Sep 07 2001 - 21:00:35 EST