Messages in this thread | | | Date | Wed, 25 Apr 2007 11:00:58 +0900 | From | Yasunori Goto <> | Subject | Re: [PATCH 2/2] Align ZONE_MOVABLE to a MAX_ORDER_NR_PAGES boundary |
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Looks good. :-) Thanks.
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
> > The boot memory allocator makes assumptions on the alignment of zone > boundaries even though the buddy allocator has no requirements on the > alignment of zones. This may cause boot problems in situations where > ZONE_MOVABLE is populated because the bootmem allocator assumes zones are > at least order-log2(BITS_PER_LONG) aligned. As the two potential users > (huge pages and memory hot-remove) of ZONE_MOVABLE would prefer a higher > alignment, this patch aligns the start of the zone instead of fixing the > different assumptions made by the bootmem allocator. > > This patch rounds the start of ZONE_MOVABLE in each node to a > MAX_ORDER_NR_PAGES boundary. If the rounding pushes the start of ZONE_MOVABLE > above the end of the node then the zone will contain no memory and will not > be used at runtime. The value is rounded up instead of down as it is > better to have the kernel-portion of memory larger than requested instead > of smaller. The impact is that the kernel-usable portion of memory because a > minimum guarantee instead of the exact size requested by the user. > > > Signed-off-by: Mel Gorman <mel@csn.ul.ie> > Acked-by: Andy Whitcroft <apw@shadowen.org> > --- > > page_alloc.c | 5 +++++ > 1 files changed, 5 insertions(+) > > diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.21-rc6-mm1-002_commonparse/mm/page_alloc.c linux-2.6.21-rc6-mm1-003_alignmovable/mm/page_alloc.c > --- linux-2.6.21-rc6-mm1-002_commonparse/mm/page_alloc.c 2007-04-24 09:38:30.000000000 +0100 > +++ linux-2.6.21-rc6-mm1-003_alignmovable/mm/page_alloc.c 2007-04-24 11:15:40.000000000 +0100 > @@ -3642,6 +3642,11 @@ restart: > usable_nodes--; > if (usable_nodes && required_kernelcore > usable_nodes) > goto restart; > + > + /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ > + for (nid = 0; nid < MAX_NUMNODES; nid++) > + zone_movable_pfn[nid] = > + roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); > } > > /**
-- Yasunori Goto
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