From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <xiao.w.wang@intel.com> Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 806191B040 for <dev@dpdk.org>; Mon, 8 Jan 2018 16:12:02 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Jan 2018 07:12:01 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,330,1511856000"; d="scan'208";a="193134644" Received: from fmsmsx105.amr.corp.intel.com ([10.18.124.203]) by fmsmga005.fm.intel.com with ESMTP; 08 Jan 2018 07:12:01 -0800 Received: from shsmsx102.ccr.corp.intel.com (10.239.4.154) by FMSMSX105.amr.corp.intel.com (10.18.124.203) with Microsoft SMTP Server (TLS) id 14.3.319.2; Mon, 8 Jan 2018 07:12:00 -0800 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.159]) by shsmsx102.ccr.corp.intel.com ([169.254.2.189]) with mapi id 14.03.0319.002; Mon, 8 Jan 2018 23:11:58 +0800 From: "Wang, Xiao W" <xiao.w.wang@intel.com> To: Yuanhan Liu <yliu@fridaylinux.org> CC: "Bie, Tiwei" <tiwei.bie@intel.com>, "dev@dpdk.org" <dev@dpdk.org>, "stephen@networkplumber.org" <stephen@networkplumber.org> Thread-Topic: [PATCH v6 2/3] net/virtio: add packet injection method Thread-Index: AQHTh2fH1krhAZUhnkW98xT0UcktDaNpbUEAgACebSA= Date: Mon, 8 Jan 2018 15:11:58 +0000 Message-ID: <B7F2E978279D1D49A3034B7786DACF406F809DA4@SHSMSX101.ccr.corp.intel.com> References: <20180107120513.142196-1-xiao.w.wang@intel.com> <20180107120513.142196-3-xiao.w.wang@intel.com> <20180108130334.GN8818@yliu-mob> In-Reply-To: <20180108130334.GN8818@yliu-mob> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ctpclassification: CTP_NT x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiZTZjMWVkMGEtMjYzOC00MzVjLWEwNDItNTgzNTFlZmZlYjI5IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjIuNS4xOCIsIlRydXN0ZWRMYWJlbEhhc2giOiJ2TkNlQmM0VHBFWk8xWTVHanBQY0tKQXkwWTRWc1RVdDRXOTdMcG5tU2N1MlJIakFRbWF1TzlqR1phbTZVbFcrIn0= dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action 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 v6 2/3] net/virtio: add packet injection method X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Mon, 08 Jan 2018 15:12:02 -0000 > -----Original Message----- > From: Yuanhan Liu [mailto:yliu@fridaylinux.org] > Sent: Monday, January 8, 2018 9:04 PM > To: Wang, Xiao W <xiao.w.wang@intel.com> > Cc: Bie, Tiwei <tiwei.bie@intel.com>; dev@dpdk.org; > stephen@networkplumber.org > Subject: Re: [PATCH v6 2/3] net/virtio: add packet injection method >=20 > On Sun, Jan 07, 2018 at 04:05:12AM -0800, Xiao Wang wrote: > > + /* > > + * App management thread and virtio interrupt handler thread > > + * both can change the 'started' flag, this lock is meant to > > + * avoid such a contention. > > + */ > > + rte_spinlock_t state_lock; >=20 > Why not turning the "started" to atomic type, so that you don't need > the lock? >=20 > --yliu To avoid impacting datapath performance, this patch doesn't change "started= " to atomic=20 type. During the interrupt handler routine, there are a series of instructions be= tween lock acquire and release. An atomic value is not suitable for this sc= enario. BRs, Xiao