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

From: Chris Down
Date: Tue Sep 08 2020 - 16:14:23 EST

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?