From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <john.mcnamara@intel.com>
Received: from mga02.intel.com (mga02.intel.com [134.134.136.20])
by dpdk.org (Postfix) with ESMTP id D04CF2BB9
for <dev@dpdk.org>; Tue, 17 Jan 2017 15:53:59 +0100 (CET)
Received: from orsmga003.jf.intel.com ([10.7.209.27])
by orsmga101.jf.intel.com with ESMTP; 17 Jan 2017 06:53:58 -0800
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.33,245,1477983600"; d="scan'208";a="923516370"
Received: from irsmsx105.ger.corp.intel.com ([163.33.3.28])
by orsmga003.jf.intel.com with ESMTP; 17 Jan 2017 06:53:57 -0800
Received: from irsmsx103.ger.corp.intel.com ([169.254.3.77]) by
irsmsx105.ger.corp.intel.com ([169.254.7.38]) with mapi id 14.03.0248.002;
Tue, 17 Jan 2017 14:53:56 +0000
From: "Mcnamara, John" <john.mcnamara@intel.com>
To: Jerin Jacob <jerin.jacob@caviumnetworks.com>
CC: "Horton, Remy" <remy.horton@intel.com>, "dev@dpdk.org" <dev@dpdk.org>,
"Pattan, Reshma" <reshma.pattan@intel.com>, Thomas Monjalon
<thomas.monjalon@6wind.com>, "olivier.matz@6wind.com"
<olivier.matz@6wind.com>, "Richardson, Bruce" <bruce.richardson@intel.com>
Thread-Topic: [dpdk-dev] [PATCH v7 5/6] lib: added new library for latency
stats
Thread-Index: AQHScBSHpoacQ3W5Mky5piO2SUYXrqE8FHOAgABvRXCAABgqgIAAEPmA
Date: Tue, 17 Jan 2017 14:53:55 +0000
Message-ID: <B27915DBBA3421428155699D51E4CFE2026B46D2@IRSMSX103.ger.corp.intel.com>
References: <1484583573-30163-1-git-send-email-remy.horton@intel.com>
<1484583573-30163-6-git-send-email-remy.horton@intel.com>
<20170117042935.GA32676@localhost.localdomain>
<B27915DBBA3421428155699D51E4CFE2026B3FEA@IRSMSX103.ger.corp.intel.com>
<20170117123418.GA2611@localhost.localdomain>
In-Reply-To: <20170117123418.GA2611@localhost.localdomain>
Accept-Language: en-GB, en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-ctpclassification: CTP_IC
x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYWNjZjQyYzUtYWVlYi00Y2RkLWE2NmYtNTk2NmE5YmNhMWYxIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6Ik15bk9oN1duSFUrSER5M25zYkMwVkU2ZEE0NmpPOGJFVnlPOEZCZUFmNTQ9In0=
x-originating-ip: [163.33.239.181]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Subject: Re: [dpdk-dev] [PATCH v7 5/6] lib: added new library for latency
stats
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <http://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: <http://dpdk.org/ml/listinfo/dev>,
<mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Tue, 17 Jan 2017 14:54:00 -0000
> -----Original Message-----
> From: Jerin Jacob [mailto:jerin.jacob@caviumnetworks.com]
> Sent: Tuesday, January 17, 2017 12:34 PM
> To: Mcnamara, John <john.mcnamara@intel.com>
> Cc: Horton, Remy <remy.horton@intel.com>; dev@dpdk.org; Pattan, Reshma
> <reshma.pattan@intel.com>; Thomas Monjalon <thomas.monjalon@6wind.com>;
> olivier.matz@6wind.com
> Subject: Re: [dpdk-dev] [PATCH v7 5/6] lib: added new library for latency
> stats
>=20
> On Tue, Jan 17, 2017 at 11:19:24AM +0000, Mcnamara, John wrote:
> > > -----Original Message-----
> > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Jerin Jacob
> > > Sent: Tuesday, January 17, 2017 4:30 AM
> > > To: Horton, Remy <remy.horton@intel.com>
> > > Cc: dev@dpdk.org; Pattan, Reshma <reshma.pattan@intel.com>; Thomas
> > > Monjalon <thomas.monjalon@6wind.com>
> > > Subject: Re: [dpdk-dev] [PATCH v7 5/6] lib: added new library for
> > > latency stats
> > >
> > > On Mon, Jan 16, 2017 at 04:19:32PM +0000, Remy Horton wrote:
> > > > From: Reshma Pattan <reshma.pattan@intel.com>
> > > >
> > > > Add a library designed to calculate latency statistics and report
> > > > them to the application when queried. The library measures
> > > > minimum, average and maximum latencies, and jitter in nano
> > > > seconds. The current implementation supports global latency stats,
> > > > i.e. per application
> > > stats.
> > > >
> > > > Signed-off-by: Reshma Pattan <reshma.pattan@intel.com>
> > > > Signed-off-by: Remy Horton <remy.horton@intel.com>
> > > > ---
> > > > MAINTAINERS | 4 +
> > > > config/common_base | 5 +
> > > > doc/api/doxy-api-index.md | 1 +
> > > > doc/api/doxy-api.conf | 1 +
> > > > doc/guides/rel_notes/release_17_02.rst | 5 +
> > > > lib/Makefile | 1 +
> > > > lib/librte_latencystats/Makefile | 57 +++
> > > > lib/librte_latencystats/rte_latencystats.c | 389
> > > +++++++++++++++++++++
> > > > lib/librte_latencystats/rte_latencystats.h | 146 ++++++++
> > > > .../rte_latencystats_version.map | 10 +
> > > > lib/librte_mbuf/rte_mbuf.h | 3 +
> > >
> > > It is a value added feature for DPDK. But what is the plan for
> > > incorporating the mbuf change? I have 8 month old mbuf change for
> > > ARM for natural alignment. If we are accepting any mbuf change then
> > > we need to include outstanding mbuf changes to avoid future ABI
> breakage.
> > >
> > > http://dpdk.org/dev/patchwork/patch/12878/
> > >
> >
> > Hi Jerin,
>=20
> Hi John,
>=20
> >
> > As far as I know the plan was to reach some sort of consensus on the
> > mbuf structure at the DPDK Userspace 2016, during and after Olivier's
> > presentation and then to make those changes during 17.02.
> >
> > However, I believe Olivier had other work commitments in this release
> > and wasn't able to work on the mbuf changes.
> >
> > The above mbuf change (and addition at the end of the struct) should
> > have gone into that mbuf rework, along with your changes.
> >
> > However, since the mbuf rework didn't happen we need to add the field
> > in this release.
>=20
> So we don't care the mbuf ABI breakage in the next release. This wasn't
> the message I got earlier for ARM's mbuf change.
>=20
> http://dpdk.org/dev/patchwork/patch/12878/
Hi Jerin,
We do care about ABI breakage but I was under the impression that the
timestamp change wasn't breaking the ABI since it was at the end of the
struct. I also ran the ABI validator against the change and it didn't show =
any
breakage.
http://dpdk.org/doc/guides/contributing/versioning.html#running-the-abi-val=
idator
The rearm_data alignment patch, on the other hand, does break ABI. I think
that is the main difference between the two patches.
If the timestamp change does break ABI then it should also wait until the m=
buf
restructuring.
> ...
>=20
> There is nothing against you or this feature. The only part concerns me
> that some set of patches can always override any rule and include in the
> release (even as marking as EXPERIMENTAL) because of its important for
> some set of consumers.
> Another set has to wait in the queue because its not important for some
> people.
> For me, it is not a sign of vendor neutral open source project.
To be fair I don't think we are trying to override any rule here.=20
Also, we aren't the only vendor looking for a timestamp in the mbuf.
Mellanox also submitted a patch:
http://dpdk.org/ml/archives/dev/2016-October/048809.html
However, it is also fair to acknowledge that the rearm_data alignment patch
shouldn't have had to wait so long. I can't really answer for that directly=
.
My feeling is that it was targeted for the mbuf rework but got forgotten
when that work slipped.
John