Re: [PATCH v4 04/17] octeontx2-pf: Initialize and config queues

[Jakub Kicinski <kuba@kernel.org>]

On Tue, 21 Jan 2020 18:51:38 +0530, sunil.kovvuri@gmail.com wrote:
> +dma_addr_t otx2_alloc_rbuf(struct otx2_nic *pfvf, struct otx2_pool *pool,
> +			   gfp_t gfp)
> +{
> +	dma_addr_t iova;
> +
> +	/* Check if request can be accommodated in previous allocated page */
> +	if (pool->page &&
> +	    ((pool->page_offset + pool->rbsize) <= PAGE_SIZE)) {
> +		pool->pageref++;
> +		goto ret;
> +	}
> +
> +	otx2_get_page(pool);
> +
> +	/* Allocate a new page */
> +	pool->page = alloc_pages(gfp | __GFP_COMP | __GFP_NOWARN,
> +				 pool->rbpage_order);
> +	if (unlikely(!pool->page))
> +		return -ENOMEM;
> +
> +	pool->page_offset = 0;
> +ret:
> +	iova = (u64)otx2_dma_map_page(pfvf, pool->page, pool->page_offset,
> +				      pool->rbsize, DMA_FROM_DEVICE);
> +	if (!iova) {
> +		if (!pool->page_offset)
> +			__free_pages(pool->page, pool->rbpage_order);
> +		pool->page = NULL;
> +		return -ENOMEM;
> +	}
> +	pool->page_offset += pool->rbsize;
> +	return iova;
> +}

You don't seem to be doing any page recycling if I'm reading this right.
Can't you use the standard in-kernel page frag allocator
(netdev_alloc_frag/napi_alloc_frag)?