From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by dpdk.org (Postfix) with ESMTP id 2C35D5920 for ; Thu, 28 Jun 2018 03:46:58 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Jun 2018 18:46:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,281,1526367600"; d="scan'208";a="211747547" Received: from fmsmsx105.amr.corp.intel.com ([10.18.124.203]) by orsmga004.jf.intel.com with ESMTP; 27 Jun 2018 18:46:24 -0700 Received: from fmsmsx120.amr.corp.intel.com (10.18.124.208) by FMSMSX105.amr.corp.intel.com (10.18.124.203) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 27 Jun 2018 18:46:24 -0700 Received: from shsmsx152.ccr.corp.intel.com (10.239.6.52) by fmsmsx120.amr.corp.intel.com (10.18.124.208) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 27 Jun 2018 18:46:24 -0700 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.82]) by SHSMSX152.ccr.corp.intel.com ([169.254.6.70]) with mapi id 14.03.0319.002; Thu, 28 Jun 2018 09:46:22 +0800 From: "Xing, Beilei" To: "Zhang, Qi Z" CC: "Wu, Jingjing" , "Yu, De" , "dev@dpdk.org" Thread-Topic: [PATCH v3] net/i40e: remove VF interrupt handler Thread-Index: AQHUDhja+DunVhdV/UiyAvSDYHVmW6R051vw Date: Thu, 28 Jun 2018 01:46:22 +0000 Message-ID: <94479800C636CB44BD422CB454846E01321D03EA@SHSMSX101.ccr.corp.intel.com> References: <20180627131527.46190-1-qi.z.zhang@intel.com> In-Reply-To: <20180627131527.46190-1-qi.z.zhang@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v3] net/i40e: remove VF interrupt handler X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Jun 2018 01:46:59 -0000 > -----Original Message----- > From: Zhang, Qi Z > Sent: Wednesday, June 27, 2018 9:15 PM > To: Xing, Beilei > Cc: Wu, Jingjing ; Yu, De ; > dev@dpdk.org; Zhang, Qi Z > Subject: [PATCH v3] net/i40e: remove VF interrupt handler >=20 > For i40evf, internal rx interrupt and adminq interrupt share the same sou= rce, > that cause a lot cpu cycles be wasted on interrupt handler on rx path. Th= is is > complained by customers which require low latency (when set > I40E_ITR_INTERVAL to small value), but have to be sufferred by tremendous > interrupts handling that eat significant CPU resources. >=20 > The patch disable pci interrupt and remove the interrupt handler, replace= it > with a low frequency (50ms) interrupt polling daemon which is implemented > by registering a alarm callback periodly, this save CPU time significentl= y: On a > typical x86 server with 2.1GHz CPU, with low latency configure (32us) we = saw > CPU usage from top commmand reduced from 20% to 0% on management > core in testpmd). >=20 > Also with the new method we can remove compile option: > I40E_ITR_INTERVAL which is used to balance between low latency and low > CPU usage previously. > Now we don't need it since we can reach both at same time. >=20 > Suggested-by: Jingjing Wu > Signed-off-by: Qi Zhang Acked-by: Beilei Xing