From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f173.google.com (mail-qk0-f173.google.com [209.85.220.173]) by dpdk.org (Postfix) with ESMTP id D6CAE7CCD; Mon, 14 Aug 2017 20:01:40 +0200 (CEST) Received: by mail-qk0-f173.google.com with SMTP id z18so54362891qka.4; Mon, 14 Aug 2017 11:01:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=DZulQwHMGdJaBkdTFrotLfQ0j9eytvLRclUrRjFEQGI=; b=pZDCDF+LE6Ck0XLRJ6E41nY/I3+YxT7LJ8MSer0YIWP6nIfOk/hPlz2bH4DwaaVFwj EOTdYl25IANUrHf4jXlIYx+th4/ba9m0zMBAQ5VLBEpvv6HU8vaQ91LtaaN0OpExFQIW BSX6WYsg2oU6vECfPGMB3myPrZS0YeJ9QOoeExwl9OcAlt+0nPTB2k+RGJAwnS8ECy8q Wtit5e4QfK7Yp2ZhhidQa+zEuxO6u+cyRbAXqCjvG0wZoSHXaNVxMMu6bLsf+MW6WkKF h19v7hIvcnrQbLsV+5nUa6bme1uInvOU17RI5QlGbuFGtJMUI0NkW2GpJaOY+fxXZF/q pShg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=DZulQwHMGdJaBkdTFrotLfQ0j9eytvLRclUrRjFEQGI=; b=BRSLWg2UZS8/eSdLNAHM8yfj4uE2WmGMVxRQbUOHhram3wNMRi0gIBGWz8NyrPJoOJ 7hSsfE2vSn/YMP5tkjT+bLIcSt8B8uqYOlnrndwlp5QxvLovAkROL5OjaS8r6CSv55/v +KTZZn0qeii3Tpn7FwdeXF0AOjvqmTb5YpxP6bSpFi+OOC2Af04vvcobn8eKBPLWnjtP NmgrACiCTEt0QiTK8Idgb2g3aOjWPE9FGfsAbC7uxYElC+N9NRhoTFA+fpp/H9cskz1w 4zZzXv5Cw4SQMvDD0mE89zzVMWeyw7R63k7R3syGjrKcySeW2HA0RfChuQQZOKgZAJZa 66Fw== X-Gm-Message-State: AHYfb5hBpLZGAloYpYT6wOlf+IN5nN/OfAY0qepnJxDW5Zu997SPBVPo FkHvhouoR9NnRBFZmXInEzX7W2Klb4SON7s= X-Received: by 10.55.166.150 with SMTP id p144mr30022447qke.269.1502733699264; Mon, 14 Aug 2017 11:01:39 -0700 (PDT) MIME-Version: 1.0 Received: by 10.55.167.2 with HTTP; Mon, 14 Aug 2017 11:01:38 -0700 (PDT) From: Venkatesh Nuthula Date: Mon, 14 Aug 2017 11:01:38 -0700 Message-ID: To: users@dpdk.org, dev@dpdk.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: [dpdk-users] Regarding changing RTE_RING_SZ_MASK to 0x7FFFFFFF X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Aug 2017 18:01:41 -0000 Hi all, I am a newbie to DPDK and in one of the applications I am building , I am trying to capture more than 150M packets and save them to file. I noticed that with packet count > 134M, the check 'count > RTE_RING_SZ_MASK' fails as RTE_RING_SZ_MASK is set to 0x0FFFFFFF. So I tried changing RTE_RING_SZ_MASK to 0x7FFFFFFF and it took me past the check 'count > RTE_RING_SZ_MASK' and the DPDK booted successfully. No error messages. But when I try to save the packets captured in memory pool into the file, I notice that it fails(my application exits without any error message) to write beyond a number of packets. I noticed that this failure to write packets happens only when I change the RTE_RING_SZ_MASK to 0x7FFFFFFF from original value 0x0FFFFFFF. I have below questions to understand this further. *1) Why is RTE_RING_SZ_MASK set to 0x0FFFFFFF. Why are the 4 bits left unused? Is it because ring size shouldn't exceed 2 power 32?2) If yes to above question, can anybody please explain why ring size can't exceed 2 power 32 as ssize_t can hold more than 2 power 32? * *3) What should be the approach if we want to capture more than 200M(200,000,000) packets? * Thanks in Advance venky