Re: [PATCH 2/3] mm/zsmalloc: remove migrate_write_lock_nested()

[Sergey Senozhatsky]

On (24/02/20 12:59), Chengming Zhou wrote:
> On 2024/2/20 12:53, Sergey Senozhatsky wrote:
> > On (24/02/20 12:51), Chengming Zhou wrote:
> >> On 2024/2/20 12:48, Sergey Senozhatsky wrote:
> >>> On (24/02/19 13:33), Chengming Zhou wrote:
> >>> [..]
> > 
> > Not really. We have, for example, the following patterns:
> > 
> > 	get_zspage_mapping()
> > 	spin_lock(&pool->lock)
> 
> Right, this pattern is not safe actually, since we can't get stable fullness
> value of zspage outside pool->lock.
> 
> But this pattern usage is only used in free_zspage path, so should be ok.
> Actually we don't use the fullness value returned from get_zspage_mapping()
> in the free_zspage() path, only use the class value to get the class.
> 
> Anyway, this pattern is confusing, I think we should clean up that?

Right, looks so.