The memblock array is in ascending order and we traverse the memblock array in reverse order so we can add some simple check to reduce the search work.
Tejun fix a underflow bug in 5d53cb27d8, but I think we could break there for the same reason. Cc: Tejun Heo <t...@kernel.org> Signed-off-by: Lin Feng <linf...@cn.fujitsu.com> --- mm/memblock.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/mm/memblock.c b/mm/memblock.c index 6259055..a710557 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -111,11 +111,18 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start, end = max(start, end); for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) { + /* + * exclude the regions out of the candidate range, since it's + * likely to find a suitable range, we ignore the worst case. + */ + if (this_start >= end) + continue; + this_start = clamp(this_start, start, end); this_end = clamp(this_end, start, end); if (this_end < size) - continue; + break; cand = round_down(this_end - size, align); if (cand >= this_start) -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/