2011-03-22 13:31:28

by Paul Mundt

[permalink] [raw]
Subject: [PATCH] mm: page allocator: Silence build_all_zonelists() section mismatch.

The memory hotplug case involves calling to build_all_zonelists() which
in turns calls in to setup_zone_pageset(). The latter is marked
__meminit while build_all_zonelists() itself has no particular
annotation. build_all_zonelists() is only handed a non-NULL pointer in
the case of memory hotplug through an existing __meminit path, so the
setup_zone_pageset() reference is always safe.

The options as such are either to flag build_all_zonelists() as __ref (as
per __build_all_zonelists()), or to simply discard the __meminit
annotation from setup_zone_pageset().

Signed-off-by: Paul Mundt <[email protected]>

---

While discarding the __meminit annotation from setup_zone_pageset() is
probably cleanest I expected some people would take issue with this so
opted for the more visually offensive __ref route. I can resend for the
other way if people prefer, or someone else can do it given that it's a
trivial change.

mm/page_alloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7945247..134e0b8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3110,7 +3110,7 @@ static __init_refok int __build_all_zonelists(void *data)
* Called with zonelists_mutex held always
* unless system_state == SYSTEM_BOOTING.
*/
-void build_all_zonelists(void *data)
+void __ref build_all_zonelists(void *data)
{
set_zonelist_order();


2011-03-23 10:38:41

by Mel Gorman

[permalink] [raw]
Subject: Re: [PATCH] mm: page allocator: Silence build_all_zonelists() section mismatch.

On Tue, Mar 22, 2011 at 10:30:45PM +0900, Paul Mundt wrote:
> The memory hotplug case involves calling to build_all_zonelists() which
> in turns calls in to setup_zone_pageset(). The latter is marked
> __meminit while build_all_zonelists() itself has no particular
> annotation. build_all_zonelists() is only handed a non-NULL pointer in
> the case of memory hotplug through an existing __meminit path, so the
> setup_zone_pageset() reference is always safe.
>
> The options as such are either to flag build_all_zonelists() as __ref (as
> per __build_all_zonelists()), or to simply discard the __meminit
> annotation from setup_zone_pageset().
>
> Signed-off-by: Paul Mundt <[email protected]>
>
> ---
>
> While discarding the __meminit annotation from setup_zone_pageset() is
> probably cleanest I expected some people would take issue with this so
> opted for the more visually offensive __ref route. I can resend for the
> other way if people prefer, or someone else can do it given that it's a
> trivial change.
>
> mm/page_alloc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>

Discarding __meminit from setup_zone_pageset() would unnecessarily grow
the kernel image in the !HOTPLUG case and setting __meminit on
build_all_zonelists() looks like it would just cause other section
mistmatch warnings so;

Acked-by: Mel Gorman <[email protected]>