From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 0D1CBA034F; Tue, 30 Mar 2021 06:56:20 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id C7F47140FA1; Tue, 30 Mar 2021 06:56:19 +0200 (CEST) Received: from mail-pl1-f169.google.com (mail-pl1-f169.google.com [209.85.214.169]) by mails.dpdk.org (Postfix) with ESMTP id D9661140FA0 for ; Tue, 30 Mar 2021 06:56:17 +0200 (CEST) Received: by mail-pl1-f169.google.com with SMTP id e14so5518108plj.2 for ; Mon, 29 Mar 2021 21:56:17 -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=z8UvolATqJD4+/KIMFQP/cG7veuVOYDCEAgJa7fMwQI=; b=d7NkR+8hvQLr6OUOrrD6HD+qX/6/tpY6ymSsOfgCofalSHxf/kvb1Bs584QW3117Xa VLPkICkZtShjxeAFK82v1RQm/PjuOYMkwA6Bsxv5QVV1m2cwvdS5WZi4PlfInSsZySgq 8YdATEC3pxuHaNypkrDNCQ6bwD8edgWkc1Irw/X+LgUr5P0wlrVORfSX2dm/KGiPv3F6 YhDwmek//UBm33eImm3urSQFJR+vA8W/pGIT1uyGvdSdJg99s6/bsKzt6mP9UoeKzVPS wzQgX4WVd9R2Qz28CiCg4RfxNYPVwgIetY6GlxQi1UIclT+G/cK8oEvRjgRg3EqghSAi 0OcQ== 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=z8UvolATqJD4+/KIMFQP/cG7veuVOYDCEAgJa7fMwQI=; b=BwnGVDgbPp43ihglISnWCy35iArisjbEfB0uxBSODiNXExQ9BDi7w06W1PpVCjsayR c72OF2WzOUnaOnEniRy8G6rBHtf63fvgkM+Cs32zENI44rNPnkqaAZVyqBCvgRA/mZYC NNvuw0DBVprMqcffpFtS/w0JLgMOARMufXBz0qzfTYRVbgoOzPkkPjiJ2qNdRrnswYjR creDqLGifKzJRULC/fmYZJZ1bb94a5pFPAMN5HBGyYHvIwjCO6DHCo5ls6kA4lkawKu/ k3LmnJ/iPCD6qttJiB7BnUFP4d7VlI6V/JJ3gNTarCFDXxlH3g9KaJ8paGcMhReAyYIp Q05A== X-Gm-Message-State: AOAM531Afh1TnZ4BhM665ZoVFao4+AVHAu/UwwmEIdr+fATBm5/qJW8K C7SoHnxhyAj5onAI3r1pkR8x+A== X-Google-Smtp-Source: ABdhPJwG3KgWcI2KHtcRp00Vj+jnH7MVSi9D5FbIUcRnlY2fe2x9eaFY4mzdRU4DFA81XViunguqIQ== X-Received: by 2002:a17:90a:8813:: with SMTP id s19mr2503179pjn.94.1617080176998; Mon, 29 Mar 2021 21:56:16 -0700 (PDT) Received: from hermes.local (76-14-218-44.or.wavecable.com. [76.14.218.44]) by smtp.gmail.com with ESMTPSA id i10sm5329452pjm.1.2021.03.29.21.56.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Mar 2021 21:56:16 -0700 (PDT) Date: Mon, 29 Mar 2021 21:56:03 -0700 From: Stephen Hemminger To: Honnappa Nagarahalli Cc: "dev@dpdk.org" , Stephen Hemminger , nd Message-ID: <20210329215603.14952fd8@hermes.local> In-Reply-To: References: <20210212013838.312623-1-sthemmin@microsoft.com> <20210303191945.94617-1-sthemmin@microsoft.com> <20210329125821.3808b0c5@hermes.local> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v3] pflock: implementation of phase-fair reader writer locks X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, 30 Mar 2021 00:18:40 +0000 Honnappa Nagarahalli wrote: > > That won't work because the implementation of trylock requires > > compare/exchange of the whole structure as an atomic operation. > I meant, placing 'rd' and 'wr' on separate cache lines. It might help in the reader-writer contention case. Except ARM default cache size is 128 which makes these locks rather large. The reader is the hot case and it doesn't look at the writer part.