From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 226A4C43613 for ; Thu, 20 Jun 2019 10:47:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA5692070B for ; Thu, 20 Jun 2019 10:47:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="psmTWWhJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726763AbfFTKr2 (ORCPT ); Thu, 20 Jun 2019 06:47:28 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:46297 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726211AbfFTKr2 (ORCPT ); Thu, 20 Jun 2019 06:47:28 -0400 Received: by mail-qt1-f196.google.com with SMTP id h21so2669338qtn.13 for ; Thu, 20 Jun 2019 03:47:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=4sRUxc78T3PiDag50aqEMvObqexRwokvbb2vXdTDTY0=; b=psmTWWhJp8n3q0p/lOK+kqddqEDQpFU1cdpSEJyXmr1m7ohPKevUOsusMGmDNSFuD+ cuEblhLd4g/pdyVfWHRR3NqIPeBhFnpcxIuXdry36EN8M94oLgtQPibDRMUxj/MnL0ma vW7vkfDXMScsJPaJTS4ZKt4UWqJwj/ESQ0Z3FI0O/FPq/kcVYcr4aTd3SPgf3O9gAsAR fLWBjaHrzSYRUl7YqY6AtrchaiaR8goC/nhlCe4+GMygu4afwsG1MKx+QeEVXEDzlCnL ZvWXEBDb5/xM36GoEuIYN3rQQusPgUEyBBSigToDDtOGF8YceAEu0f5dmjDwYjxsRQoj D7Cg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=4sRUxc78T3PiDag50aqEMvObqexRwokvbb2vXdTDTY0=; b=rFmxvC7Q2HlzafT9M3a2CX/081Rpx/SIJ7/VttVpeid90l+vQwDeLoLEYQb0Fhiz6q TYT3o49Z7/ByVIVHt6da+KZeF5sXDNHlP6lTcE0q6dyD6WViHCJvfvKO3dc+QKbKuxNC 5DmKtumClWz37z1jzQbXbMlhIwN1OErgVSS/0W5X3vRXsGuYTxY+nM1eBjJVB6DGA70N fNCgbJM9XSXsSTZiUk8+Gvd+8PRfTg3y45Or97CICBR7Isab+ZTs5k4fV17pv+vWE3aD mZnQVEiGi+KYluCA+aCGXYAnGwFvk7SPborJbH3PI7cqk4WvS6lTB4XeWaRHo8ivK0Fj z8sw== X-Gm-Message-State: APjAAAU224VW0tNKIhOF298fAST30yLw9ADA5ud17IwnHLxxQ+T9IuDi 0M7z6kztIlX1QHcTxBcK1W8= X-Google-Smtp-Source: APXvYqxWmZypaMzjKk/9r7pkngeJ+lFeIzyvqlZDuP2NGsnNPsP5Bh3kR9sGBZGWuJ3hCXtaZvuusQ== X-Received: by 2002:ac8:3908:: with SMTP id s8mr110014212qtb.224.1561027647385; Thu, 20 Jun 2019 03:47:27 -0700 (PDT) Received: from [10.246.221.134] ([50.234.174.228]) by smtp.gmail.com with ESMTPSA id p64sm13329230qkf.60.2019.06.20.03.47.26 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Thu, 20 Jun 2019 03:47:26 -0700 (PDT) Subject: Re: [PATCH net-next v4 1/7] igb: clear out tstamp after sending the packet To: Vedang Patel , netdev@vger.kernel.org Cc: jeffrey.t.kirsher@intel.com, davem@davemloft.net, jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us, intel-wired-lan@lists.osuosl.org, vinicius.gomes@intel.com, l@dorileo.org, jakub.kicinski@netronome.com, m-karicheri2@ti.com, sergei.shtylyov@cogentembedded.com References: <1560966016-28254-1-git-send-email-vedang.patel@intel.com> <1560966016-28254-2-git-send-email-vedang.patel@intel.com> From: Eric Dumazet Message-ID: Date: Thu, 20 Jun 2019 06:47:25 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <1560966016-28254-2-git-send-email-vedang.patel@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 6/19/19 10:40 AM, Vedang Patel wrote: > skb->tstamp is being used at multiple places. On the transmit side, it > is used to determine the launchtime of the packet. It is also used to > determine the software timestamp after the packet has been transmitted. > > So, clear out the tstamp value after it has been read so that we do not > report false software timestamp on the receive side. > > Signed-off-by: Vedang Patel > --- > drivers/net/ethernet/intel/igb/igb_main.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c > index fc925adbd9fa..f66dae72fe37 100644 > --- a/drivers/net/ethernet/intel/igb/igb_main.c > +++ b/drivers/net/ethernet/intel/igb/igb_main.c > @@ -5688,6 +5688,7 @@ static void igb_tx_ctxtdesc(struct igb_ring *tx_ring, > */ > if (tx_ring->launchtime_enable) { > ts = ns_to_timespec64(first->skb->tstamp); > + first->skb->tstamp = 0; Please provide more explanations. Why only this driver would need this ? > context_desc->seqnum_seed = cpu_to_le32(ts.tv_nsec / 32); > } else { > context_desc->seqnum_seed = 0; >