From: Benjamin Herrenschmidt on
To constraint the search of a region between two boundaries,
which will be used by the new NUMA aware allocator among others.

Signed-off-by: Benjamin Herrenschmidt <benh(a)kernel.crashing.org>
---
mm/memblock.c | 27 ++++++++++++++++-----------
1 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 8715f09..468ff43 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -117,19 +117,18 @@ static phys_addr_t __init memblock_find_region(phys_addr_t start, phys_addr_t en
return MEMBLOCK_ERROR;
}

-static phys_addr_t __init memblock_find_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
+static phys_addr_t __init memblock_find_base(phys_addr_t size, phys_addr_t align,
+ phys_addr_t start, phys_addr_t end)
{
long i;
- phys_addr_t base = 0;
- phys_addr_t res_base;

BUG_ON(0 == size);

size = memblock_align_up(size, align);

/* Pump up max_addr */
- if (max_addr == MEMBLOCK_ALLOC_ACCESSIBLE)
- max_addr = memblock.current_limit;
+ if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
+ end = memblock.current_limit;

/* We do a top-down search, this tends to limit memory
* fragmentation by keeping early boot allocs near the
@@ -138,13 +137,19 @@ static phys_addr_t __init memblock_find_base(phys_addr_t size, phys_addr_t align
for (i = memblock.memory.cnt - 1; i >= 0; i--) {
phys_addr_t memblockbase = memblock.memory.regions[i].base;
phys_addr_t memblocksize = memblock.memory.regions[i].size;
+ phys_addr_t bottom, top, found;

if (memblocksize < size)
continue;
- base = min(memblockbase + memblocksize, max_addr);
- res_base = memblock_find_region(memblockbase, base, size, align);
- if (res_base != MEMBLOCK_ERROR)
- return res_base;
+ if ((memblockbase + memblocksize) <= start)
+ break;
+ bottom = max(memblockbase, start);
+ top = min(memblockbase + memblocksize, end);
+ if (bottom >= top)
+ continue;
+ found = memblock_find_region(bottom, top, size, align);
+ if (found != MEMBLOCK_ERROR)
+ return found;
}
return MEMBLOCK_ERROR;
}
@@ -204,7 +209,7 @@ static int memblock_double_array(struct memblock_type *type)
new_array = kmalloc(new_size, GFP_KERNEL);
addr = new_array == NULL ? MEMBLOCK_ERROR : __pa(new_array);
} else
- addr = memblock_find_base(new_size, sizeof(phys_addr_t), MEMBLOCK_ALLOC_ACCESSIBLE);
+ addr = memblock_find_base(new_size, sizeof(phys_addr_t), 0, MEMBLOCK_ALLOC_ACCESSIBLE);
if (addr == MEMBLOCK_ERROR) {
pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
memblock_type_name(type), type->max, type->max * 2);
@@ -416,7 +421,7 @@ phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, ph
*/
size = memblock_align_up(size, align);

- found = memblock_find_base(size, align, max_addr);
+ found = memblock_find_base(size, align, 0, max_addr);
if (found != MEMBLOCK_ERROR &&
memblock_add_region(&memblock.reserved, found, size) >= 0)
return found;
--
1.7.0.4

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