Re: [PATCH] mm/memblock:Do not retry a range that has already been checked

From: Mike Rapoport
Date: Sun May 24 2020 - 13:53:17 EST


On Sun, May 24, 2020 at 11:16:40PM +0900, daeroro wrote:
> The range that has already been checked
> don't have to be checked in a second attempt.

The first attempts tries to find free memory in the interval [min_addr,
max_addr) and the second attempt does not care about min_addr and looks
for free memory in the interval [0, max_addr).

Is there a problem you see with this algorthim?

> Signed-off-by: daeroro <skseofh@xxxxxxxxx>
> ---
> mm/memblock.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 39aceafc57f6..6f72fae415ee 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -1489,7 +1489,7 @@ static void * __init memblock_alloc_internal(
>
> /* retry allocation without lower limit */
> if (!alloc && min_addr)
> - alloc = memblock_alloc_range_nid(size, align, 0, max_addr, nid,
> + alloc = memblock_alloc_range_nid(size, align, 0, min_addr, nid,
> exact_nid);
>
> if (!alloc)
> --
> 2.17.1
>

--
Sincerely yours,
Mike.