From: Jerin Jacob <jerin.jacob@caviumnetworks.com>
To: Jia He <hejianet@gmail.com>
Cc: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
"Zhao, Bing" <ilovethull@163.com>,
Olivier MATZ <olivier.matz@6wind.com>,
"dev@dpdk.org" <dev@dpdk.org>,
"jia.he@hxt-semitech.com" <jia.he@hxt-semitech.com>,
"jie2.liu@hxt-semitech.com" <jie2.liu@hxt-semitech.com>,
"bing.zhao@hxt-semitech.com" <bing.zhao@hxt-semitech.com>,
"Richardson, Bruce" <bruce.richardson@intel.com>,
jianbo.liu@arm.com, hemant.agrawal@nxp.com
Subject: Re: [dpdk-dev] [PATCH] ring: guarantee ordering of cons/prod loading when doing enqueue/dequeue
Date: Fri, 3 Nov 2017 18:17:41 +0530 [thread overview]
Message-ID: <20171103124740.GA20326@jerin> (raw)
In-Reply-To: <fc05d426-a48a-4887-7365-85822d3996ac@gmail.com>
-----Original Message-----
> Date: Fri, 3 Nov 2017 10:55:40 +0800
> From: Jia He <hejianet@gmail.com>
> To: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> Cc: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>, "Zhao, Bing"
> <ilovethull@163.com>, Olivier MATZ <olivier.matz@6wind.com>,
> "dev@dpdk.org" <dev@dpdk.org>, "jia.he@hxt-semitech.com"
> <jia.he@hxt-semitech.com>, "jie2.liu@hxt-semitech.com"
> <jie2.liu@hxt-semitech.com>, "bing.zhao@hxt-semitech.com"
> <bing.zhao@hxt-semitech.com>, "Richardson, Bruce"
> <bruce.richardson@intel.com>, jianbo.liu@arm.com, hemant.agrawal@nxp.com
> Subject: Re: [dpdk-dev] [PATCH] ring: guarantee ordering of cons/prod
> loading when doing enqueue/dequeue
> User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101
> Thunderbird/52.4.0
>
> Hi Jerin
>
>
> On 11/2/2017 4:57 PM, Jia He Wrote:
> >
> > Hi， Jerin
> > please see my performance test below
> > On 11/2/2017 3:04 AM, Jerin Jacob Wrote:
> > [...]
> > > Should it be like instead?
> > >
> > > +#else
> > > + *old_head = __atomic_load_n(&r->cons.head, __ATOMIC_ACQUIRE);
> > > + const uint32_t prod_tail = __atomic_load_n(&r->prod.tail,
> > > __ATOMIC_ACQUIRE);
> > > It would be nice to see how much overhead it gives.ie back to back
> > > __ATOMIC_ACQUIRE.
> > I can NOT test ring_perf_autotest in our server because of the something
> > wrong in PMU counter.
> > All the return value of rte_rdtsc is 0 with and without your provided ko
> > module. I am still
> > investigating the reason.
> >
>
> Hi Jerin
>
> As for the root cause of rte_rdtsc issue, it might be due to the pmu counter
> frequency is too low
>
> in our arm64 server("Amberwing" from qualcom)
>
> [586990.057779] arch_timer_get_cntfrq()=20000000
>
> Only 20MHz instead of 100M/200MHz, and CNTFRQ_EL0 is not even writable in
> kernel space.
May not be true, as I guess, linux 'perf' write those register in kernel
space. Another option could be write from ATF/Secure boot loader if that is the case.
>
> Maybe the code in ring_perf_autotest needs to be changed?
Increase the "iterations" to measure @ 200MHz.
>
> e.g.
>
> printf("SC empty dequeue: %.2F\n",
> (double)(sc_end-sc_start) / iterations);
> printf("MC empty dequeue: %.2F\n",
> (double)(mc_end-mc_start) / iterations);
>
> Otherwise it is always 0 if the time difference divides by iterations.
>
>
> --
> Cheers,
> Jia
>
next prev parent reply other threads:[~2017-11-03 12:48 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-10 9:56 Jia He
2017-10-12 15:53 ` Olivier MATZ
2017-10-12 16:15 ` Stephen Hemminger
2017-10-12 17:05 ` Ananyev, Konstantin
2017-10-12 17:23 ` Jerin Jacob
2017-10-13 1:02 ` Jia He
2017-10-13 1:15 ` Jia He
2017-10-13 1:16 ` Jia He
2017-10-13 1:49 ` Jerin Jacob
2017-10-13 3:23 ` Jia He
2017-10-13 5:57 ` Zhao, Bing
2017-10-13 7:33 ` Jianbo Liu
2017-10-13 8:20 ` Jia He
2017-10-19 10:02 ` Ananyev, Konstantin
2017-10-19 11:18 ` Zhao, Bing
2017-10-19 14:15 ` Ananyev, Konstantin
2017-10-19 20:02 ` Ananyev, Konstantin
2017-10-20 1:57 ` Jia He
2017-10-20 5:43 ` Jerin Jacob
2017-10-23 8:49 ` Jia He
2017-10-23 9:05 ` Kuusisaari, Juhamatti
2017-10-23 9:10 ` Bruce Richardson
2017-10-23 10:06 ` Jerin Jacob
2017-10-24 2:04 ` Jia He
2017-10-25 13:26 ` Jerin Jacob
2017-10-26 2:27 ` Jia He
2017-10-31 2:55 ` Jia He
2017-10-31 11:14 ` Jerin Jacob
2017-11-01 2:53 ` Jia He
2017-11-01 19:04 ` Jerin Jacob
2017-11-02 1:09 ` Jia He
2017-11-02 8:57 ` Jia He
2017-11-03 2:55 ` Jia He
2017-11-03 12:47 ` Jerin Jacob [this message]
2017-11-01 4:48 ` Jia He
2017-11-01 19:10 ` Jerin Jacob
2017-10-20 7:03 ` Ananyev, Konstantin
2017-10-13 0:24 ` Liu, Jie2
2017-10-13 2:12 ` Zhao, Bing
2017-10-13 2:34 ` Jerin Jacob
2017-10-16 10:51 ` Kuusisaari, Juhamatti
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