memblock: Fix size aligning of memblock_alloc_base_nid()

memblock allocator aligns @size to @align to reduce the amount
of fragmentation.  Commit:

 7bd0b0f0da ("memblock: Reimplement memblock allocation using reverse free area iterator")

Broke it by incorrectly relocating @size aligning to
memblock_find_in_range_node().  As the aligned size is not
propagated back to memblock_alloc_base_nid(), the actually
reserved size isn't aligned.

While this increases memory use for memblock reserved array,
this shouldn't cause any critical failure; however, it seems
that the size aligning was hiding a use-beyond-allocation bug in
sparc64 and losing the aligning causes boot failure.

The underlying problem is currently being debugged but this is a
proper fix in itself, it's already pretty late in -rc cycle for
boot failures and reverting the change for debugging isn't
difficult. Restore the size aligning moving it to
memblock_alloc_base_nid().

Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120228205621.GC3252@dhcp-172-17-108-109.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <alpine.SOC.1.00.1202130942030.1488@math.ut.ee>

diff --git a/mm/memblock.c b/mm/memblock.c
index 77b5f22..99f2855 100644 (file)
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -99,9 +99,6 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
        phys_addr_t this_start, this_end, cand;
        u64 i;
 
-       /* align @size to avoid excessive fragmentation on reserved array */
-       size = round_up(size, align);
-
        /* pump up @end */
        if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
                end = memblock.current_limit;
@@ -731,6 +728,9 @@ static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size,
 {
        phys_addr_t found;
 
+       /* align @size to avoid excessive fragmentation on reserved array */
+       size = round_up(size, align);
+
        found = memblock_find_in_range_node(0, max_addr, size, align, nid);
        if (found && !memblock_reserve(found, size))
                return found;