From patchwork Sun Jan 20 10:12:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heiner Kallweit X-Patchwork-Id: 1028137 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="TRLthEpL"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43j9VR0nYbz9sCr for ; Sun, 20 Jan 2019 21:13:02 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730427AbfATKML (ORCPT ); Sun, 20 Jan 2019 05:12:11 -0500 Received: from mail-wm1-f68.google.com ([209.85.128.68]:38855 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730409AbfATKML (ORCPT ); Sun, 20 Jan 2019 05:12:11 -0500 Received: by mail-wm1-f68.google.com with SMTP id m22so8219750wml.3 for ; Sun, 20 Jan 2019 02:12:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:subject:to:cc:message-id:date:user-agent:mime-version :content-language:content-transfer-encoding; bh=km0e3O5HHDC8pUbf6sswLLQI9RHe8bTGUTU4iskuMLA=; b=TRLthEpLSn/9aLyT5mzTsOSax5PfjBqDkNEHegD0BcXzIjcpaSDNVWkz73+hR2fwYq En4RoWARNz+XuAV3bLhC9wku74dX4dyFIPV7+9K6eOmV0e6ysEbNzyTC6sedE6wDcyBu JH/3+1jIcYApkEc73tqfjqpYThBQ/rrDxlW2oZkE8oHfbcvCRLjaRcnWOBvL6Yg7TOL4 JV5KPLuHSSNz8O9WNGgsqIM8RQ0D66FAoasGeI8SP4f0Sn+TE1wOxFmFlNya7b/6rhan Cr0T3kUUqhDAueE6+mw1t8FQtQs7TPytZStmxsvT/T2276Gkj+GCFrcKCdivDUIhdHqN dxEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:subject:to:cc:message-id:date:user-agent :mime-version:content-language:content-transfer-encoding; bh=km0e3O5HHDC8pUbf6sswLLQI9RHe8bTGUTU4iskuMLA=; b=s8P67sGf028U7SOXgd1lfVHG2WFNt9VgXfhrcnskLz6d2Tq6FQBCds9ykgAAXUR6EQ cKdHAHniiPfJ9VFgZq9AkVkg3z1q2XM0PhuOGnYikPfVvttAwOIcPzIIZkhbIfjg3Wvn faXVZ5FYSnz0y8iX0XHEnh74dGnOz0WjschR3/TwWv+ks2lzLv3LmuZTLy/i0cJo1kTh V0Otg3R8cwa8nP5fP3m14RUbgfhOf8z40pstXr8ZAPrnhxobvGcVHiUiZT1+jifyGMjw V24zJ5paU/YTsRHF74Cjiq4aq3f4u95cbcfWUNvmYn/IHTOsJLkwg3ErV/TMXG1rnLXM BNpg== X-Gm-Message-State: AJcUukcSOKVRueAsmgBWZIlpDA/YdJwk5JVpXej6o250AhPgM+vcPOiE gRqKvO4osj9sd7HELMGopYk= X-Google-Smtp-Source: ALg8bN5kcr4hRoCDH8mgBvQhUXSlgYAUjDNAlIIuQOs82ewSQPjwHWpQ+LtNvCp/5t5khxhZ1NWaDQ== X-Received: by 2002:a1c:9d57:: with SMTP id g84mr21541541wme.16.1547979128644; Sun, 20 Jan 2019 02:12:08 -0800 (PST) Received: from ?IPv6:2003:ea:8bf1:e200:dc25:cc52:f4a2:4f63? (p200300EA8BF1E200DC25CC52F4A24F63.dip0.t-ipconnect.de. [2003:ea:8bf1:e200:dc25:cc52:f4a2:4f63]) by smtp.googlemail.com with ESMTPSA id f137sm41185719wmg.29.2019.01.20.02.12.07 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 20 Jan 2019 02:12:08 -0800 (PST) From: Heiner Kallweit Subject: [PATCH net-next] r8169: improve rx buffer allocation To: David Miller , Realtek linux nic maintainers Cc: "netdev@vger.kernel.org" , Eric Dumazet Message-ID: Date: Sun, 20 Jan 2019 11:12:01 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 Content-Language: en-US Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 8 years ago, as part of 6f0333b8fde4 ("r8169: use 50% less ram for RX ring"), the alignment requirement for rx buffers was silently changed from 8 bytes to 16 bytes. I found nothing explaining this, also the chip specs I have only mention an 8 byte requirement. AFAICS kmalloc_node() guarantees allocated memory to be at least "long long" aligned, what is 8 bytes on a 32 bit machine. So we can take this memory as-is and avoid some overhead by changing the alignment requirement back to 8 bytes. Signed-off-by: Heiner Kallweit --- drivers/net/ethernet/realtek/r8169.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c index e790a4116..970c82694 100644 --- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -5659,11 +5659,6 @@ static inline void rtl8169_mark_to_asic(struct RxDesc *desc) desc->opts1 = cpu_to_le32(DescOwn | eor | R8169_RX_BUF_SIZE); } -static inline void *rtl8169_align(void *data) -{ - return (void *)ALIGN((long)data, 16); -} - static struct sk_buff *rtl8169_alloc_rx_data(struct rtl8169_private *tp, struct RxDesc *desc) { @@ -5676,15 +5671,13 @@ static struct sk_buff *rtl8169_alloc_rx_data(struct rtl8169_private *tp, if (!data) return NULL; - if (rtl8169_align(data) != data) { - kfree(data); - data = kmalloc_node(R8169_RX_BUF_SIZE + 15, GFP_KERNEL, node); - if (!data) - return NULL; + /* Memory should be properly aligned, but better check. */ + if (!IS_ALIGNED((unsigned long)data, 8)) { + netdev_err_once(tp->dev, "RX buffer not 8-byte-aligned\n"); + goto err_out; } - mapping = dma_map_single(d, rtl8169_align(data), R8169_RX_BUF_SIZE, - DMA_FROM_DEVICE); + mapping = dma_map_single(d, data, R8169_RX_BUF_SIZE, DMA_FROM_DEVICE); if (unlikely(dma_mapping_error(d, mapping))) { if (net_ratelimit()) netif_err(tp, drv, tp->dev, "Failed to map RX DMA!\n"); @@ -6290,7 +6283,6 @@ static struct sk_buff *rtl8169_try_rx_copy(void *data, struct sk_buff *skb; struct device *d = tp_to_dev(tp); - data = rtl8169_align(data); dma_sync_single_for_cpu(d, addr, pkt_size, DMA_FROM_DEVICE); prefetch(data); skb = napi_alloc_skb(&tp->napi, pkt_size);