From owner-freebsd-net@freebsd.org Thu Apr 28 18:13:46 2016 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B0317B1F5D2 for ; Thu, 28 Apr 2016 18:13:46 +0000 (UTC) (envelope-from bazzoola@gmail.com) Received: from mail-pf0-x243.google.com (mail-pf0-x243.google.com [IPv6:2607:f8b0:400e:c00::243]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 7613312C0 for ; Thu, 28 Apr 2016 18:13:46 +0000 (UTC) (envelope-from bazzoola@gmail.com) Received: by mail-pf0-x243.google.com with SMTP id r187so11860230pfr.2 for ; Thu, 28 Apr 2016 11:13:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=to:from:subject:message-id:date:user-agent:mime-version :content-transfer-encoding; bh=v7qIfXum5wPwD1B2cCR6W02rnLmmmhwDlVzoKlmKPBM=; b=kzuyEsdQh43+7p92GuZ81tA2vp6Xmyer0cazdlJixgtM4O0J/jex7H0xc3X+I1Stb7 OYeHfXiKWvGVZkrtzpxoQE7vOC/Jn2FAIZLgKWChOkbyZsQ3MXJR09D5xp8QSVRMaY0c gCohpZKEH6e/gGeRYQs8gT0PCuzzQ7gkzXsbhiyhi8qAqTjdr3QER99lq7myPy3iIVr/ YCO6IE9SpX0AxXcp83eb7rYF/R1XTWm1LRa9iT63hR/C4/xI6c11s9dfDuLAH/YHfw+j wPycZlHGQblZh2pydb3Dg4HvGHKLSNCjEvW5j8tfdadXNorrrkjIPjTngchTgpg+KlIr 9lWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:to:from:subject:message-id:date:user-agent :mime-version:content-transfer-encoding; bh=v7qIfXum5wPwD1B2cCR6W02rnLmmmhwDlVzoKlmKPBM=; b=KHazrRmRkNg8Wmolw3yjAQTf63hEhsD/OHSJIwahJLLYMsA01WUQgVVC1c/RIDWRBL glWXDyPe9q8usMhSVmLtrVewmq3HN0KNavOFrzzbQNNZ25DwoZ4obxtfJ1rwdvbkXJIb DDEW1Cvq6Z0Jh8mWQsj1IsBaWCW22qyEtyVwRqk/VfoEtejx+qh/GnHxryNGZ44npKqr C80SvnAn+9QvBaEN1pj/rSyrsDhApwfBk6vo4n1QTGC0li4Lds3256seRYAwRLYJriwb rHZrS9pYvtAlLxYrvMh7ZZML9+Q+RYasAvxViQKK2AndZYHVb6jyX0HTCSoQ6J9N1Fqp ftIw== X-Gm-Message-State: AOPr4FXwa7Jq+yAOIrrixRBEdAF2ZuIqp71KiVMY+qdtTB9o6tk+obsZlPWaMzgW9zkLFA== X-Received: by 10.98.80.150 with SMTP id g22mr22610072pfj.132.1461867225970; Thu, 28 Apr 2016 11:13:45 -0700 (PDT) Received: from ?IPv6:2620:83:8001:24::1:567? ([2620:83:8001:24::1:567]) by smtp.googlemail.com with ESMTPSA id we8sm17051889pac.29.2016.04.28.11.13.45 for (version=TLSv1/SSLv3 cipher=OTHER); Thu, 28 Apr 2016 11:13:45 -0700 (PDT) To: freebsd-net@freebsd.org From: bazzoola Subject: netmap overrun counters Message-ID: Date: Thu, 28 Apr 2016 11:13:45 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Apr 2016 18:13:46 -0000 Hi! Two questions: (1) Is there a way to know when netmap rx rings overrun? Most NIC drivers provide MPC (missed packet count) and sysctl for rx_overrun. I would like to know if my application is not reading as fast, i.e., no frames are being dropped. (2) What is the benefit of NETMAP_DO_RX_POLL? I do see the buffers being updated when I set this flag but 'tail' is not advancing unless I read. Bazz