在 2020/8/7 下午10:51, Alexander Duyck 写道:

I wonder if this entire section shouldn't be restructured. This is the
only spot I can see where we are resetting the LRU flag instead of
pulling the page from the LRU list with the lock held. Looking over
the code it seems like something like that should be possible. I am
not sure the LRU lock is really protecting us in either the
PageCompound check nor the skip bits. It seems like holding a
reference on the page should prevent it from switching between
compound or not, and the skip bits are per pageblock with the LRU bits
being per node/memcg which I would think implies that we could have
multiple LRU locks that could apply to a single skip bit.

Hi Alexander,

I don't find problem yet on compound or skip bit usage. Would you clarify the
issue do you concerned? 

Thanks!