Re: [PATCH] zsmalloc: do not use bit_spin_lock

[Mike Galbraith]

On Sun, 2020-12-20 at 02:22 +0200, Vitaly Wool wrote:
> zsmalloc takes bit spinlock in its _map() callback and releases it
> only in unmap() which is unsafe and leads to zswap complaining
> about scheduling in atomic context.
>
> To fix that and to improve RT properties of zsmalloc, remove that
> bit spinlock completely and use a bit flag instead.

It also does get_cpu_var() in map(), put_cpu_var() in unmap().

	-Mike