On Tue, 2013-08-27 at 17:37 +0800, Tang Chen wrote:
> This patch modifies the memblock_find_in_range_node() to support two
> different allocation orders. After this patch, memblock will check
> memblock.current_order, and decide in which order to allocate memory.
>
> Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
> Reviewed-by: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
> ---
> mm/memblock.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++---------
> 1 files changed, 75 insertions(+), 15 deletions(-)
>
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 8f1e2d4..961d4a5 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -85,6 +85,77 @@ static long __init_memblock memblock_overlaps_region(struct memblock_type *type,
> }
>
> /**
> + * __memblock_find_range - find free area utility
> + * @start: start of candidate range, can be %MEMBLOCK_ALLOC_ACCESSIBLE
> + * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
> + * @size: size of free area to find
> + * @align: alignment of free area to find
> + * @nid: nid of the free area to find, %MAX_NUMNODES for any node
> + *
> + * Utility called from memblock_find_in_range_node(), find free area from
> + * lower address to higher address.
> + *
> + * RETURNS:
> + * Found address on success, %0 on failure.
> + */
> +phys_addr_t __init_memblock
> +__memblock_find_range(phys_addr_t start, phys_addr_t end,
> + phys_addr_t size, phys_addr_t align, int nid)
This func should be static as it must be an internal func.
> +{
> + phys_addr_t this_start, this_end, cand;
> + u64 i;
> +
> + for_each_free_mem_range(i, nid, &this_start, &this_end, NULL) {
> + this_start = clamp(this_start, start, end);
> + this_end = clamp(this_end, start, end);
> +
> + cand = round_up(this_start, align);
> + if (cand < this_end && this_end - cand >= size)
> + return cand;
> + }
> + return 0;
> +}
> +
> +/**
> + * __memblock_find_range_rev - find free area utility, in reverse order
> + * @start: start of candidate range, can be %MEMBLOCK_ALLOC_ACCESSIBLE
> + * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
> + * @size: size of free area to find
> + * @align: alignment of free area to find
> + * @nid: nid of the free area to find, %MAX_NUMNODES for any node
> + *
> + * Utility called from memblock_find_in_range_node(), find free area from
> + * higher address to lower address.
> + *
> + * RETURNS:
> + * Found address on success, %0 on failure.
> + */
> +phys_addr_t __init_memblock
> +__memblock_find_range_rev(phys_addr_t start, phys_addr_t end,
> + phys_addr_t size, phys_addr_t align, int nid)
Ditto.
> +{
> + phys_addr_t this_start, this_end, cand;
> + u64 i;
> +
> + for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
> + this_start = clamp(this_start, start, end);
> + this_end = clamp(this_end, start, end);
> +
> + /*
> + * Just in case that (this_end - size) underflows and cause
> + * (cand >= this_start) to be true incorrectly.
> + */
> + if (this_end < size)
> + break;
> +
> + cand = round_down(this_end - size, align);
> + if (cand >= this_start)
> + return cand;
> + }
> + return 0;
> +}
> +
> +/**
> * memblock_find_in_range_node - find free area in given range and node
> * @start: start of candidate range, can be %MEMBLOCK_ALLOC_ACCESSIBLE
> * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
> @@ -110,9 +181,6 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
> phys_addr_t end, phys_addr_t size,
> phys_addr_t align, int nid)
> {
> - phys_addr_t this_start, this_end, cand;
> - u64 i;
> -
> /* pump up @start and @end */
> if (start == MEMBLOCK_ALLOC_ACCESSIBLE)
> start = memblock.current_limit_low;
> @@ -123,18 +191,10 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
> start = max_t(phys_addr_t, start, PAGE_SIZE);
> end = max(start, end);
>
> - for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
> - this_start = clamp(this_start, start, end);
> - this_end = clamp(this_end, start, end);
> -
> - if (this_end < size)
> - continue;
> -
> - cand = round_down(this_end - size, align);
> - if (cand >= this_start)
> - return cand;
> - }
> - return 0;
> + if (memblock.current_order == MEMBLOCK_ORDER_DEFAULT)
This needs to use MEMBLOCK_ORDER_HIGH_TO_LOW since the code should be
independent from the value of MEMBLOCK_ORDER_DEFAULT.
Thanks,
-Toshi
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