From patchwork Wed May 12 12:50:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 437756 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=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 59603C433ED for ; Wed, 12 May 2021 12:52:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 211E761175 for ; Wed, 12 May 2021 12:52:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231540AbhELMxW (ORCPT ); Wed, 12 May 2021 08:53:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:52584 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231500AbhELMxA (ORCPT ); Wed, 12 May 2021 08:53:00 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 059DE6142F; Wed, 12 May 2021 12:51:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620823903; bh=Siu+BFq1+PyRburw9qoE86u5X6rSLCp6lJqQVcNDPqc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LwaeoVY+8c3y1kzeLBO4Ullt7X+BfZVfIZ8R/Ytv+tp/zFFVf5VdsmkIgMJBFMYmN I8bQxQyjGKnUlxwFtVn+9Hb8+QXIh8FAS/P7cFKpbVlXbMNoD5ZVCZWMHkmtcVhfY3 gcXvwD0t211vjoNggLs+KokFNvDgZQ9XsL7Bf00po1hUA5Oie92PvAqRfAN670pD9A Xk+LaOqcJETunVoppc8a1LndC394p9I0lTPwxpBgHhzvynsC/hbg7FFGBbwaqoMHWW ZZzok/8MKL5dBQnQq0nWDJeU9Izv/I0J6E3ofpBq2rs6UJawXb2hX8h3ggiz1lBJon 9ShYhrGdxBWCA== Received: by mail.kernel.org with local (Exim 4.94.2) (envelope-from ) id 1lgoKz-0018iM-4T; Wed, 12 May 2021 14:51:41 +0200 From: Mauro Carvalho Chehab To: Linux Doc Mailing List Cc: Mauro Carvalho Chehab , "David S. Miller" , "Jonathan Corbet" , Jakub Kicinski , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v2 24/40] docs: networking: scaling.rst: Use ASCII subset instead of UTF-8 alternate symbols Date: Wed, 12 May 2021 14:50:28 +0200 Message-Id: X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 Sender: Mauro Carvalho Chehab Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The conversion tools used during DocBook/LaTeX/Markdown->ReST conversion and some automatic rules which exists on certain text editors like LibreOffice turned ASCII characters into some UTF-8 alternatives that are better displayed on html and PDF. While it is OK to use UTF-8 characters in Linux, it is better to use the ASCII subset instead of using an UTF-8 equivalent character as it makes life easier for tools like grep, and are easier to edit with the some commonly used text/source code editors. Also, Sphinx already do such conversion automatically outside literal blocks: https://docutils.sourceforge.io/docs/user/smartquotes.html So, replace the occurences of the following UTF-8 characters: - U+2019 ('’'): RIGHT SINGLE QUOTATION MARK - U+201c ('“'): LEFT DOUBLE QUOTATION MARK - U+201d ('”'): RIGHT DOUBLE QUOTATION MARK Signed-off-by: Mauro Carvalho Chehab --- Documentation/networking/scaling.rst | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/Documentation/networking/scaling.rst b/Documentation/networking/scaling.rst index 3d435caa3ef2..e1a0c88193fa 100644 --- a/Documentation/networking/scaling.rst +++ b/Documentation/networking/scaling.rst @@ -30,7 +30,7 @@ queues to distribute processing among CPUs. The NIC distributes packets by applying a filter to each packet that assigns it to one of a small number of logical flows. Packets for each flow are steered to a separate receive queue, which in turn can be processed by separate CPUs. This mechanism is -generally known as “Receive-side Scaling” (RSS). The goal of RSS and +generally known as "Receive-side Scaling" (RSS). The goal of RSS and the other scaling techniques is to increase performance uniformly. Multi-queue distribution can also be used for traffic prioritization, but that is not the focus of these techniques. @@ -46,7 +46,7 @@ indirection table and reading the corresponding value. Some advanced NICs allow steering packets to queues based on programmable filters. For example, webserver bound TCP port 80 packets -can be directed to their own receive queue. Such “n-tuple” filters can +can be directed to their own receive queue. Such "n-tuple" filters can be configured from ethtool (--config-ntuple). @@ -114,7 +114,7 @@ RSS. Being in software, it is necessarily called later in the datapath. Whereas RSS selects the queue and hence CPU that will run the hardware interrupt handler, RPS selects the CPU to perform protocol processing above the interrupt handler. This is accomplished by placing the packet -on the desired CPU’s backlog queue and waking up the CPU for processing. +on the desired CPU's backlog queue and waking up the CPU for processing. RPS has some advantages over RSS: 1) it can be used with any NIC @@ -128,20 +128,20 @@ netif_receive_skb(). These call the get_rps_cpu() function, which selects the queue that should process a packet. The first step in determining the target CPU for RPS is to calculate a -flow hash over the packet’s addresses or ports (2-tuple or 4-tuple hash +flow hash over the packet's addresses or ports (2-tuple or 4-tuple hash depending on the protocol). This serves as a consistent hash of the associated flow of the packet. The hash is either provided by hardware or will be computed in the stack. Capable hardware can pass the hash in the receive descriptor for the packet; this would usually be the same hash used for RSS (e.g. computed Toeplitz hash). The hash is saved in skb->hash and can be used elsewhere in the stack as a hash of the -packet’s flow. +packet's flow. Each receive hardware queue has an associated list of CPUs to which RPS may enqueue packets for processing. For each received packet, an index into the list is computed from the flow hash modulo the size of the list. The indexed CPU is the target for processing the packet, -and the packet is queued to the tail of that CPU’s backlog queue. At +and the packet is queued to the tail of that CPU's backlog queue. At the end of the bottom half routine, IPIs are sent to any CPUs for which packets have been queued to their backlog queue. The IPI wakes backlog processing on the remote CPU, and any queued packets are then processed @@ -298,7 +298,7 @@ CPU for packet processing (from get_rps_cpu()) the rps_sock_flow table and the rps_dev_flow table of the queue that the packet was received on are compared. If the desired CPU for the flow (found in the rps_sock_flow table) matches the current CPU (found in the rps_dev_flow -table), the packet is enqueued onto that CPU’s backlog. If they differ, +table), the packet is enqueued onto that CPU's backlog. If they differ, the current CPU is updated to match the desired CPU if one of the following is true: @@ -356,7 +356,7 @@ the application thread consuming the packets of each flow is running. Accelerated RFS should perform better than RFS since packets are sent directly to a CPU local to the thread consuming the data. The target CPU will either be the same CPU where the application runs, or at least a CPU -which is local to the application thread’s CPU in the cache hierarchy. +which is local to the application thread's CPU in the cache hierarchy. To enable accelerated RFS, the networking stack calls the ndo_rx_flow_steer driver function to communicate the desired hardware @@ -369,7 +369,7 @@ The hardware queue for a flow is derived from the CPU recorded in rps_dev_flow_table. The stack consults a CPU to hardware queue map which is maintained by the NIC driver. This is an auto-generated reverse map of the IRQ affinity table shown by /proc/interrupts. Drivers can use -functions in the cpu_rmap (“CPU affinity reverse map”) kernel library +functions in the cpu_rmap ("CPU affinity reverse map") kernel library to populate the map. For each CPU, the corresponding queue in the map is set to be one whose processing CPU is closest in cache locality.