On Tue, 18 Jul 2023 21:48:01 +0000 Haiyang Zhang wrote:
> Add page pool for RX buffers for faster buffer cycle and reduce CPU
> usage.
>
> The standard page pool API is used.
> @@ -1437,8 +1437,12 @@ static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe,
>
> act = mana_run_xdp(ndev, rxq, &xdp, buf_va, pkt_len);
>
> - if (act == XDP_REDIRECT && !rxq->xdp_rc)
> + if (act == XDP_REDIRECT && !rxq->xdp_rc) {
> + if (from_pool)
> + page_pool_release_page(rxq->page_pool,
> + virt_to_head_page(buf_va));
IIUC you should pass the page_pool as the last argument to
xdp_rxq_info_reg_mem_model() and then the page will be recycled
by the core, you shouldn't release it.
Not to mention the potential race in releasing the page _after_
giving its ownership to someone else.
> - page = dev_alloc_page();
> + if (is_napi) {
> + page = page_pool_dev_alloc_pages(rxq->page_pool);
> + *from_pool = true;
> + } else {
> + page = dev_alloc_page();
FWIW if you're only calling this outside NAPI during init, when NAPI
can't yet run, I _think_ it's okay to use page_pool_dev_alloc..
> + pprm.pool_size = RX_BUFFERS_PER_QUEUE;
> + pprm.napi = &cq->napi;
> + pprm.dev = gc->dev;
> + pprm.dma_dir = DMA_FROM_DEVICE;
If you're not setting PP_FLAG_DMA_MAP you don't have to fill in .dev
and .dma_dir
--
pw-bot: cr
