From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id C9DBB2E8A for ; Wed, 5 Apr 2017 11:48:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1491385688; x=1522921688; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=yxgsmTHJhNep2yOoYeeGQYVXMOA7EppbMxgdr3lTGd0=; b=ZQh4YKSAjFvxNlqEKCRzVn07c0qv0I0ayXD2guxxP3gQ1FDpWGvqVEju R57mSQmrom7P4xmQq1j7bsxcgB20cw==; Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Apr 2017 02:48:07 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,278,1486454400"; d="scan'208";a="84651812" Received: from irsmsx153.ger.corp.intel.com ([163.33.192.75]) by fmsmga005.fm.intel.com with ESMTP; 05 Apr 2017 02:48:05 -0700 Received: from irsmsx103.ger.corp.intel.com ([169.254.3.241]) by IRSMSX153.ger.corp.intel.com ([163.33.192.75]) with mapi id 14.03.0319.002; Wed, 5 Apr 2017 10:48:05 +0100 From: "Richardson, Bruce" To: Thomas Monjalon , Olivier Matz CC: "dev@dpdk.org" , "Ananyev, Konstantin" , "mb@smartsharesystems.com" , "Chilikin, Andrey" , "jblunck@infradead.org" , "nelio.laranjeiro@6wind.com" , "arybchenko@solarflare.com" , "jerin.jacob@caviumnetworks.com" Thread-Topic: [PATCH v2 0/8] mbuf: structure reorganization Thread-Index: AQHSrWEZIJQTsmEvgESh87rwe8c9NqG2dQKAgAATFzA= Date: Wed, 5 Apr 2017 09:48:04 +0000 Message-ID: <59AF69C657FD0841A61C55336867B5B066751DDC@IRSMSX103.ger.corp.intel.com> References: <1488966121-22853-1-git-send-email-olivier.matz@6wind.com> <20170404162807.20157-1-olivier.matz@6wind.com> <2948467.vjfs1XSdfO@xps13> In-Reply-To: <2948467.vjfs1XSdfO@xps13> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiNDgwNTZhYzktMmU4NC00YTBiLThiYTktNmViMTM0OGViNjY4IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE2LjUuOS4zIiwiVHJ1c3RlZExhYmVsSGFzaCI6IitIemVcL0xudDNtMm1FZWNJR1J2VmRaVm1kXC9nbURsb1NHKzVzKzhiaXJDND0ifQ== x-ctpclassification: CTP_IC dlp-product: dlpe-windows dlp-version: 10.0.102.7 dlp-reaction: no-action x-originating-ip: [163.33.239.180] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v2 0/8] mbuf: structure reorganization 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: Wed, 05 Apr 2017 09:48:09 -0000 > -----Original Message----- > From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com] > Sent: Wednesday, April 5, 2017 10:38 AM > To: Olivier Matz > Cc: dev@dpdk.org; Ananyev, Konstantin ; > Richardson, Bruce ; mb@smartsharesystems.com; > Chilikin, Andrey ; jblunck@infradead.org; > nelio.laranjeiro@6wind.com; arybchenko@solarflare.com; > jerin.jacob@caviumnetworks.com > Subject: Re: [PATCH v2 0/8] mbuf: structure reorganization >=20 > 2017-04-04 18:27, Olivier Matz: > > Based on discussions done in [1] and in this thread, this patchset > > reorganizes the mbuf. > > > > The main changes are: > > - reorder structure to increase vector performance on some non-ia > > platforms. > > - add a 64bits timestamp field in the 1st cache line. This timestamp > > is not normalized, i.e. no unit or time reference is enforced. A > > library may be added to do this job in the future. > > - m->next, m->nb_segs, and m->refcnt are always initialized for mbufs > > in the pool, avoiding the need of setting m->next (located in the > > 2nd cache line) in the Rx path for mono-segment packets. > > - change port and nb_segs to 16 bits > > - move seqn in the 2nd cache line >=20 > Applied, thanks for the long work >=20 +1 > We need to add a patch to bump ABIVER and document the changes. >=20 >=20 > > Things discussed but not done in the patchset: > > - move refcnt and nb_segs to the 2nd cache line: many drivers sets > > them in the Rx path, so it could introduce a performance regression, > or > > it would require to change all the drivers, which is not an easy task= . >=20 > If it is worth to move these fields in 2nd cache line, can we plan to > rework drivers for not setting them in Rx? Any drivers that are already setting these fields directly may get a perf b= ump by not doing so. However, I'm not sure there is a compelling need to mo= ve them down just yet. Let's try and avoid breaking the mbuf again for a fe= w releases. >=20 > > Once this patchset is pushed, the Rx path of drivers could be > > optimized a bit, by removing writes to m->next, m->nb_segs and > > m->refcnt. The patch 4/8 gives an idea of what could be done. >=20 > Yes drivers patches are welcome :) > Please target RC2 for these changes. We indeed plan to do so! /Bruce