Re: [LTP] [linux-next:master] [mm] 47325a5c88: WARNING:at_mm/slub.c:#free_large_kmalloc

Andrew Morton
2024-07-10T19:18:24Z

On Wed, 10 Jul 2024 11:49:09 -0700 (PDT) Hugh Dickins <hughd@google.com> wrote:

> It's a long time since I was active hereabouts, but the bot report
> and your flurry of updates make me think that you should step back,
> slow down, and look more carefully at the precedents here.
>
> IIRC, the main problem is that parts of the swap_info_struct can
> still be in use from before while you're wanting to set up new values.
> Observe how alloc_swap_info() may return a fresh or an old allocation.
> Observe how enable_swap_info() is called after getting swapon_mutex
> late in swapon(), once past all possiblities of error.
>
> I expect that your new zeromap needs to be taking the same care as is
> taken with swap_map and cluster_info: to be safe, follow their example
> in both swapon() and swapoff().

Thanks. I've dropped the series "mm: store zero pages to be swapped
out in a bitmap" from mm-stable. Let's revisit in the next -rc cycle.