From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id D549AA04C0 for ; Mon, 28 Sep 2020 22:54:01 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 9F8F41D168; Mon, 28 Sep 2020 22:54:00 +0200 (CEST) Received: from mail-pg1-f196.google.com (mail-pg1-f196.google.com [209.85.215.196]) by dpdk.org (Postfix) with ESMTP id 397431D168 for ; Mon, 28 Sep 2020 22:53:59 +0200 (CEST) Received: by mail-pg1-f196.google.com with SMTP id e18so1972512pgd.4 for ; Mon, 28 Sep 2020 13:53:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=i06UHfB0hkb/QVgnkX2G5yyPnhB84S29bb4gNpg3M20=; b=gXhtXtf6LIFZVXZWCPHQ/Ar1kkgHx3swmvhcqOFFi0IYJiMNGt5eEkuuAeKK9+Kenh h5M9CDiHyUg0S41okvKPM2lxcxxfZdJ/CC+oo5MZKvXWTSsoAIeryfFCDZs8V/X769CN +c9XuEBqe9jsQ7e/fb9saVZhwB+KI1mAkImMq+sEgQC8kkM4xNx4mjvgEyTdlTZe5tPv sr0Ar3tzG9tlqghDVqTooy7Pz1mvUAyjNAdF7X1h6F0R5Rejx1fvUXKIgbVmfqFGCYZt Zhfjbg+GmSBMdSRoGFteTjcWSNSDKPwvsHYZxFHwZL6Lws8rn7DO1+ZWnqRX89zT9Sgx UeHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=i06UHfB0hkb/QVgnkX2G5yyPnhB84S29bb4gNpg3M20=; b=M7mnKfhjqgDs5nJSIZnmj8NdxvkeveFwb90+9ISBQMmqymmPElATLqo+l0ArsSIjV9 n/vIA4NgKQ8avqLGsuab7EsWUDAQJuxB4Y0+5fgCmsfLPQ9+1liCuVphzJyA6nUkUy6Q L3oKVdTrc6febbfyM0tGAhUPr+mVfanOAiUFV68JFiQvt7YnthI+BE34LEyZNUpTdxSk YlTfMUx47crC6/2BR+CTJdghUvCNG90ls8VNha0QbbtTQ57Pm8HQYDhb9Ui6Z3KnhC// ggt17bHFqbWG6MHlm9V/kAK6WkIotYPHpkrdLZ6+tF8htXDZcFeiCvY0KoW1SKetUQYq h6pA== X-Gm-Message-State: AOAM533Y4x/mRFVbJOahtk7YQRK2KHQd5pQ0hnpe+aY/bHJrNratnMB/ cRSdbURZDLZYtAZbDDXVru2F0A== X-Google-Smtp-Source: ABdhPJz/NdW4PuECOM5AkM9xCkROOaa/T6A7Wg0qyZ4i+6TWL/IsDO65tzQE+BdlFgWO+jJeCX5Dww== X-Received: by 2002:a63:6bc9:: with SMTP id g192mr701155pgc.236.1601326437340; Mon, 28 Sep 2020 13:53:57 -0700 (PDT) Received: from hermes.local (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id u2sm462966pfk.85.2020.09.28.13.53.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Sep 2020 13:53:57 -0700 (PDT) Date: Mon, 28 Sep 2020 13:53:53 -0700 From: Stephen Hemminger To: Honnappa Nagarahalli Cc: dev@dpdk.org, phil.yang@arm.com, jgrajcia@cisco.com, ferruh.yigit@intel.com, nd@arm.com, stable@dpdk.org Message-ID: <20200928135353.774a805f@hermes.local> In-Reply-To: <20200928190334.40624-1-honnappa.nagarahalli@arm.com> References: <20200921192254.20560-1-honnappa.nagarahalli@arm.com> <20200928190334.40624-1-honnappa.nagarahalli@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH v2 1/8] net/memif: do not update local copy of tail in tx function X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org Sender: "stable" On Mon, 28 Sep 2020 14:03:27 -0500 Honnappa Nagarahalli wrote: > In the case of S2M queues, the receiver synchronizes with the sender > (i.e. informs of the packets it has received) using ring->tail. > Hence, the sender does not need to update last_tail. > > In the case of M2S queues, the receiver uses last_tail to > keep track of the descriptors it has received. The > sender is not required to update the last_tail. Updating > the last_tail makes it a shared variable between the > transmitter and receiver affecting the performance. > > Fixes: 09c7e63a71f9 ("net/memif: introduce memory interface PMD") > Cc: jgrajcia@cisco.com > Cc: stable@dpdk.org > > Signed-off-by: Honnappa Nagarahalli > Reviewed-by: Phil Yang > Reviewed-by: Ruifeng Wang This patch series will conflict with the pending master/slave patchset. Please let the master/slave renaming go in first.