Re: [PATCH] mm/vmscan: fix infinite loop in drop_slab_node

[Chris Down <chris@xxxxxxxxxxxxxx>]

drop_caches by its very nature can be extremely performance intensive -- if 
someone wants to abort after trying too long, they can just send a 
TASK_KILLABLE signal, no? If exiting the loop and returning to usermode doesn't 
reliably work when doing that, then _that's_ something to improve, but this 
looks premature to me until that's demonstrated not to work.

zangchunxin@xxxxxxxxxxxxx writes:
> In one drop caches action, only traverse memcg once maybe is better.
> If user need more memory, they can do drop caches again.

Can you please provide some measurements of the difference in reclamation in 
practice?