On 9/8/20 5:09 PM, Chris Down wrote: > 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. Hm there might be existings scripts (even though I dislike those) running drop_caches periodically, and they are currently not set up to be killed, so one day it might surprise someone. Dropping should be a one-time event, not a continual reclaim. Maybe we could be a bit smarter and e.g. double the threshold currently hardcoded as "10" with each iteration? > 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? >
