On Fri, Dec 26, 2025 at 12:27 AM Michael S. Tsirkin <[email protected]> wrote: > > 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?
Yes, and I think the logic here is to fallback to ksoftirqd if the allocation fails too much. Thanks > > > > > > > Not saying refill work is a great hack, but that is the reason for it. > > > -- > > > MST > > > > > > > Thanks >
