On Wed, 7 Aug 2024 19:00:35 +0800 Yunsheng Lin wrote:

quoted

Note that page pool pages may last forever, we have seen it happen
e.g. when application leaks a socket and page is stuck in its rcv queue.  

We saw some page_pool pages might last forever too, but were not sure
if it was the same reason as above? Are there some cmds/ways to debug
if a application leaks a socket and page is stuck in its rcv queue?

I used drgn to scan all sockets to find the page.

quoted

Hopefully this is fine in this particular case, as we will only stall
unregistering of devices which want the page pool to manage the DMA
mapping for them, i.e. HW backed netdevs. And obviously keeping
the netdev around is preferable to a crash.