From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 8161F9AF6 for ; Thu, 12 Feb 2015 14:08:47 +0100 (CET) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP; 12 Feb 2015 05:01:37 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,565,1418112000"; d="scan'208";a="453672348" Received: from irsmsx153.ger.corp.intel.com ([163.33.192.75]) by FMSMGA003.fm.intel.com with ESMTP; 12 Feb 2015 04:54:03 -0800 Received: from irsmsx105.ger.corp.intel.com ([169.254.7.81]) by IRSMSX153.ger.corp.intel.com ([169.254.9.2]) with mapi id 14.03.0195.001; Thu, 12 Feb 2015 13:08:44 +0000 From: "Ananyev, Konstantin" To: "Liang, Cunming" , Olivier MATZ , "dev@dpdk.org" Thread-Topic: [PATCH v5 18/19] ring: add sched_yield to avoid spin forever Thread-Index: AQHQRpxji6uzr387zUaYyTTxX0+np5zs3WAAgAAei4CAAABUMA== Date: Thu, 12 Feb 2015 13:08:43 +0000 Message-ID: <2601191342CEEE43887BDE71AB977258213E5500@irsmsx105.ger.corp.intel.com> References: <1422842559-13617-1-git-send-email-cunming.liang@intel.com> <1423728996-3004-1-git-send-email-cunming.liang@intel.com> <1423728996-3004-19-git-send-email-cunming.liang@intel.com> <54DC8B78.2040009@6wind.com> In-Reply-To: Accept-Language: en-IE, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: 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 v5 18/19] ring: add sched_yield to avoid spin forever X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Feb 2015 13:08:48 -0000 > -----Original Message----- > From: Liang, Cunming > Sent: Thursday, February 12, 2015 1:05 PM > To: Olivier MATZ; dev@dpdk.org > Cc: Ananyev, Konstantin > Subject: RE: [PATCH v5 18/19] ring: add sched_yield to avoid spin forever >=20 > Hi, >=20 > > -----Original Message----- > > From: Olivier MATZ [mailto:olivier.matz@6wind.com] > > Sent: Thursday, February 12, 2015 7:16 PM > > To: Liang, Cunming; dev@dpdk.org > > Cc: Ananyev, Konstantin > > Subject: Re: [PATCH v5 18/19] ring: add sched_yield to avoid spin forev= er > > > > Hi, > > > > On 02/12/2015 09:16 AM, Cunming Liang wrote: > > > Add a sched_yield() syscall if the thread spins for too long, waiting= other thread > > to finish its operations on the ring. > > > That gives pre-empted thread a chance to proceed and finish with ring > > enqnue/dequeue operation. > > > The purpose is to reduce contention on the ring. By ring_perf_test, i= t doesn't > > shows additional perf penalty. > > > > > > Signed-off-by: Cunming Liang > > > --- > > > v5 changes: > > > add RTE_RING_PAUSE_REP to config file > > > > > > v4 changes: > > > update and add more comments on sched_yield() > > > > > > v3 changes: > > > new patch adding sched_yield() in rte_ring to avoid long spin > > > > > > config/common_bsdapp | 1 + > > > config/common_linuxapp | 1 + > > > lib/librte_ring/rte_ring.h | 31 +++++++++++++++++++++++++++---- > > > 3 files changed, 29 insertions(+), 4 deletions(-) > > > > > > diff --git a/config/common_bsdapp b/config/common_bsdapp > > > index 57bacb8..52c5143 100644 > > > --- a/config/common_bsdapp > > > +++ b/config/common_bsdapp > > > @@ -234,6 +234,7 @@ CONFIG_RTE_PMD_PACKET_PREFETCH=3Dy > > > CONFIG_RTE_LIBRTE_RING=3Dy > > > CONFIG_RTE_LIBRTE_RING_DEBUG=3Dn > > > CONFIG_RTE_RING_SPLIT_PROD_CONS=3Dn > > > +CONFIG_RTE_RING_PAUSE_REP=3Dn > > > > Maybe it's better to use CONFIG_RTE_RING_PAUSE_REP=3D0 instead? > > If I understand well, it has to be set to an integer value to > > enable it, am I correct? > [LCM] If RTE_RING_PAUSE_REP=3DN (no define), by default will use 0. If it= 's set to 'y'(=3D1), will issue yield in the most frequent rate. > It also can set as integer to assign any number. All cases works for this= configure. > One point is in configure file, just demonstrate the default way to use i= t. > It can't prevent to use anything unexpected. Except we rule the n & y ill= egal for this option. > The meaningful value of it can write in the doc. I also think that it is better avoid 'y' and 'n' (though as you said it wou= ld work), but use integers for all cases. Less confusion for the users. Konstantin=20 > > > > Thanks, > > Olivier