From patchwork Tue Aug 18 07:07:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li RongQing X-Patchwork-Id: 262401 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5BEBC433E1 for ; Tue, 18 Aug 2020 07:08:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC82120658 for ; Tue, 18 Aug 2020 07:08:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726587AbgHRHIP (ORCPT ); Tue, 18 Aug 2020 03:08:15 -0400 Received: from mx55.baidu.com ([61.135.168.55]:18138 "EHLO tc-sys-mailedm02.tc.baidu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726043AbgHRHIO (ORCPT ); Tue, 18 Aug 2020 03:08:14 -0400 Received: from localhost (cp01-cos-dev01.cp01.baidu.com [10.92.119.46]) by tc-sys-mailedm02.tc.baidu.com (Postfix) with ESMTP id B9A2611C005B; Tue, 18 Aug 2020 15:07:57 +0800 (CST) From: Li RongQing To: netdev@vger.kernel.org, intel-wired-lan@lists.osuosl.org Subject: [PATCH][v3] i40e: optimise prefetch page refcount Date: Tue, 18 Aug 2020 15:07:57 +0800 Message-Id: <1597734477-27859-1-git-send-email-lirongqing@baidu.com> X-Mailer: git-send-email 1.7.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org refcount of rx_buffer page will be added here originally, so prefetchw is needed, but after commit 1793668c3b8c ("i40e/i40evf: Update code to better handle incrementing page count"), and refcount is not added everytime, so change prefetchw as prefetch, now it mainly services page_address(), but which accesses struct page only when WANT_PAGE_VIRTUAL or HASHED_PAGE_VIRTUAL is defined otherwise it returns address based on offset, so we prefetch it conditionally Jakub suggested to define prefetch_page_address in a common header Reported-by: kernel test robot Suggested-by: Jakub Kicinski Signed-off-by: Li RongQing Tested-by: Aaron Brown diff with v2: fix a build warning -Wvisibility diff with v1: create a common function prefetch_page_address drivers/net/ethernet/intel/i40e/i40e_txrx.c | 2 +- include/linux/prefetch.h | 8 ++++++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 62f5b2d35f63..5f9fe55bb66d 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -1953,7 +1953,7 @@ static struct i40e_rx_buffer *i40e_get_rx_buffer(struct i40e_ring *rx_ring, struct i40e_rx_buffer *rx_buffer; rx_buffer = i40e_rx_bi(rx_ring, rx_ring->next_to_clean); - prefetchw(rx_buffer->page); + prefetch_page_address(rx_buffer->page); /* we are reusing so sync this buffer for CPU use */ dma_sync_single_range_for_cpu(rx_ring->dev, diff --git a/include/linux/prefetch.h b/include/linux/prefetch.h index 13eafebf3549..b83a3f944f28 100644 --- a/include/linux/prefetch.h +++ b/include/linux/prefetch.h @@ -15,6 +15,7 @@ #include #include +struct page; /* prefetch(x) attempts to pre-emptively get the memory pointed to by address "x" into the CPU L1 cache. @@ -62,4 +63,11 @@ static inline void prefetch_range(void *addr, size_t len) #endif } +static inline void prefetch_page_address(struct page *page) +{ +#if defined(WANT_PAGE_VIRTUAL) || defined(HASHED_PAGE_VIRTUAL) + prefetch(page); +#endif +} + #endif