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 543E8A034E; Wed, 22 Dec 2021 17:55:27 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 25F3640040; Wed, 22 Dec 2021 17:55:27 +0100 (CET) Received: from mail-pj1-f50.google.com (mail-pj1-f50.google.com [209.85.216.50]) by mails.dpdk.org (Postfix) with ESMTP id D5A414003C for ; Wed, 22 Dec 2021 17:55:25 +0100 (CET) Received: by mail-pj1-f50.google.com with SMTP id lr15-20020a17090b4b8f00b001b19671cbebso3178233pjb.1 for ; Wed, 22 Dec 2021 08:55:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Baiz+sEkJVy8ApCMZAy0olsKAkEIlA1FHjd1wXtzNZk=; b=4gviA6/79Q5xNaXn69V5cqmxiCBburo0yfhdvXhjOVS6qsFbTqGK2334pNhadIuFLJ Kpod9/d3K6ncY7XFX7llYEYUrGqTOF4dGA34fZnIwRJwoD8J8hltf4tkjnpfynTeY0YR HtqalUjKvi8BbuhQnd5Cw1U3kWIGEgOZZIbLsDFcvw0cyVS+EFbcLu903J1EsZgGjLuk rTh1s3YyKF+I8lQNUFoor0sFbEN77E0+FnxTCTdhwkh2ci28ND37QNEZ9T60Mqr1d/fB ZhA6nzyKUl6WXs2d/lOD2H55QcoMftjNykw0lleBnVNQsUSwIPGO7OGv9vo5EMqIz6Tp L17A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Baiz+sEkJVy8ApCMZAy0olsKAkEIlA1FHjd1wXtzNZk=; b=XL7grTCtHbwy2FnkTp2ynHncPV3i5/axsbBmNh8CbCjquVX13VXgjiPOUn4qKsBD9s 1EZn+z3agR2+HcjVk4RK247v+BWfpME7uLK3J7KY8EnF9XpsBIB0EZkvuQA5DYzcmG/4 OCrpEQ1IlIgGO0Bf6GXAhxlKfa/MupwRWOeeLnqeU4QP5i/WzCKa7Xno5tXnpI4F2bUd X8L1CWM4lnjGTFjunt9zk5HTE6wwzDEOtPNG4j4lWcLv49DfUYVaX+inrQ1KIwPKd2Uh 7W5w6TsGL9QQLyzPQ4xcOtfVOzIh9oSTXG5HEkJAo/4hcwxqoXtVRj/ksbomhQuFe6Xk N1pg== X-Gm-Message-State: AOAM533L8jxzPyjzmaclqbjGtHm0Pwkm9VRVx8ui2OjPhBUmUHMvg/ur 1+oBUBNXOBFP5qGl1NIrBI03EA== X-Google-Smtp-Source: ABdhPJzAq+IOtmvBuUU2EP5KMBvu1kPyyxca4oTKaJMxAKnxo55FkT6dV2U3+DJzCj0JbegCbcdOLA== X-Received: by 2002:a17:90b:3143:: with SMTP id ip3mr2308636pjb.34.1640192125085; Wed, 22 Dec 2021 08:55:25 -0800 (PST) Received: from hermes.local (204-195-112-199.wavecable.com. [204.195.112.199]) by smtp.gmail.com with ESMTPSA id c5sm2570069pgi.89.2021.12.22.08.55.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Dec 2021 08:55:24 -0800 (PST) Date: Wed, 22 Dec 2021 08:55:22 -0800 From: Stephen Hemminger To: Yanling Song Cc: , , , , Subject: Re: [PATCH v1 01/25] drivers/net: introduce a new PMD driver Message-ID: <20211222085522.4cf80006@hermes.local> In-Reply-To: <20211222085400.0000408c@ramaxel.com> References: <913359f582b165a3fcfe5efbd4dab76476690a53.1639636621.git.songyl@ramaxel.com> <20211219114031.146a4c1e@hermes.local> <20211222085400.0000408c@ramaxel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 On Wed, 22 Dec 2021 08:54:00 +0800 Yanling Song wrote: > > If all you want is jiffie accuracy, you could use > > CLOCK_MONOTONIC_COARSE. > > > I did not get your point: CLOCK_MONOTONIC is more accurate than > CLOCK_MONOTONIC_COARSE, right? CLOCK_MONOTONIC ends up using the TSC counter and values in the shared page (VDSO) to compute time accurately. CLOCK_MONOTONIC_COARSE is faster and good enough if you only want ms accuracy. It just reads a value from shared page and avoids the TSC instruction.