On Fri, 28 Apr 2023 18:16:19 +0200 Jesper Dangaard Brouer wrote: > This removes the workqueue scheme that periodically tests when > inflight reach zero such that page_pool memory can be freed. > > This change adds code to fast-path free checking for a shutdown flags > bit after returning PP pages. We can remove the warning without removing the entire delayed freeing scheme. I definitely like the SHUTDOWN flag and patch 2 but I'm a bit less clear on why the complexity of datapath freeing is justified. Can you explain? > Performance is very important for PP, as the fast path is used for > XDP_DROP use-cases where NIC drivers recycle PP pages directly into PP > alloc cache. > > This patch (since V3) shows zero impact on this fast path. Micro > benchmarked with [1] on Intel CPU E5-1650 @3.60GHz. The slight code > reorg of likely() are deliberate.
