On Wed, 14 Jun 2023 10:14:25 -0700 Tony Nguyen wrote:

+static bool idpf_rx_can_reuse_page(struct idpf_rx_buf *rx_buf)
+{
+	unsigned int last_offset = PAGE_SIZE - rx_buf->buf_size;
+	struct idpf_page_info *pinfo;
+	unsigned int pagecnt_bias;
+	struct page *page;
+
+	pinfo = &rx_buf->page_info[rx_buf->page_indx];
+	pagecnt_bias = pinfo->pagecnt_bias;
+	page = pinfo->page;
+
+	if (unlikely(!dev_page_is_reusable(page)))
+		return false;
+
+	if (PAGE_SIZE < 8192) {
+		/* For 2K buffers, we can reuse the page if we are the
+		 * owner. For 4K buffers, we can reuse the page if there are
+		 * no other others.
+		 */
+		if (unlikely((page_count(page) - pagecnt_bias) >
+			     pinfo->reuse_bias))
+			return false;
+	} else if (pinfo->page_offset > last_offset) {
+		return false;
+	}
+
+	/* If we have drained the page fragment pool we need to update
+	 * the pagecnt_bias and page count so that we fully restock the
+	 * number of references the driver holds.
+	 */
+	if (unlikely(pagecnt_bias == 1)) {
+		page_ref_add(page, USHRT_MAX - 1);
+		pinfo->pagecnt_bias = USHRT_MAX;
+	}
+
+	return true;
+}

If you want to do local recycling you must use the page pool first,
and then share the analysis of how much and why the recycling helps.