Re: [PATCH v2] mm/page_alloc: fix watchdog soft lockups during set_zone_contiguous()

From: Andrew Morton
Date: Fri Apr 17 2020 - 18:12:57 EST


On Thu, 16 Apr 2020 09:34:17 +0200 David Hildenbrand <david@xxxxxxxxxx> wrote:

> Without CONFIG_PREEMPT, it can happen that we get soft lockups detected,
> e.g., while booting up.
>
> ...
>
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1607,6 +1607,7 @@ void set_zone_contiguous(struct zone *zone)
> if (!__pageblock_pfn_to_page(block_start_pfn,
> block_end_pfn, zone))
> return;
> + cond_resched();
> }
>
> /* We confirm that there is no hole */

I added cc:stable to this one. Please let me know if that wasn't a
good idea.