On Thu, Dec 25, 2025 at 03:33:29PM +0800, Jason Wang wrote: > On Wed, Dec 24, 2025 at 9:48 AM Michael S. Tsirkin <[email protected]> wrote: > > > > On Wed, Dec 24, 2025 at 09:37:14AM +0800, Xuan Zhuo wrote: > > > > > > Hi Jason, > > > > > > I'm wondering why we even need this refill work. Why not simply let NAPI > > > retry > > > the refill on its next run if the refill fails? That would seem much > > > simpler. > > > This refill work complicates maintenance and often introduces a lot of > > > concurrency issues and races. > > > > > > Thanks. > > > > refill work can refill from GFP_KERNEL, napi only from ATOMIC. > > > > And if GFP_ATOMIC failed, aggressively retrying might not be a great idea. > > Btw, I see some drivers are doing things as Xuan said. E.g > mlx5e_napi_poll() did: > > busy |= INDIRECT_CALL_2(rq->post_wqes, > mlx5e_post_rx_mpwqes, > mlx5e_post_rx_wqes, > > ... > > if (busy) { > if (likely(mlx5e_channel_no_affinity_change(c))) { > work_done = budget; > goto out; > ...
is busy a GFP_ATOMIC allocation failure? > > > > Not saying refill work is a great hack, but that is the reason for it. > > -- > > MST > > > > Thanks
