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From: "Li, Xiaoyun" <xiaoyun.li@intel.com>
To: Thomas Monjalon <thomas@monjalon.net>
Cc: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
	"Richardson, Bruce" <bruce.richardson@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>,
	"Lu, Wenzhuo" <wenzhuo.lu@intel.com>,
	"Zhang, Helin" <helin.zhang@intel.com>,
	"ophirmu@mellanox.com" <ophirmu@mellanox.com>
Subject: Re: [dpdk-dev] [PATCH v8 1/3] eal/x86: run-time dispatch over memcpy
Date: Wed, 25 Oct 2017 10:32:25 +0000	[thread overview]
Message-ID: <B9E724F4CB7543449049E7AE7669D82F481870@SHSMSX101.ccr.corp.intel.com> (raw)
In-Reply-To: <4158692.mhjs8xbxgm@xps>



> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> Sent: Wednesday, October 25, 2017 17:00
> To: Li, Xiaoyun <xiaoyun.li@intel.com>
> Cc: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Richardson,
> Bruce <bruce.richardson@intel.com>; dev@dpdk.org; Lu, Wenzhuo
> <wenzhuo.lu@intel.com>; Zhang, Helin <helin.zhang@intel.com>;
> ophirmu@mellanox.com
> Subject: Re: [dpdk-dev] [PATCH v8 1/3] eal/x86: run-time dispatch over
> memcpy
> 
> 25/10/2017 10:54, Li, Xiaoyun:
> > > > > > > I think we should focus on micro-benchmark and find a
> > > > > > > reasonnable threshold for a reasonnable drop tradeoff.
> > > > > > >
> > > > > > Sadly, it may not be that simple. What shows best performance
> > > > > > for
> > > > > > micro- benchmarks may not show the same effect in a real
> application.
> > > > > >
> > > > > > /Bruce
> > > > >
> > > > > Then how to measure the performance?
> > > > >
> > > > > And I cannot reproduce 15% drop on mellanox.
> > > > > Could the person who tested 15% drop help to do test again with
> > > > > 1024 threshold and see if there is any improvement?
> > > >
> > > > As Bruce said, best performance on micro-benchmark may not show
> > > > the
> > > same effect in real applications.
> > > > And I cannot reproduce the 15% drop.
> > > > And I don't know if raising the threshold can improve the perf or not.
> > > > Could the person who tested 15% drop help to do test again with
> > > > 1024
> > > threshold and see if there is any improvement?
> > >
> > > As I already asked before - why not to make that threshold dynamic?
> > > Konstantin
> > >
> > I want to confirm that raising threshold is useful. Then can make it dynamic
> and set it very large as default.
> 
> You can confirm it with micro-benchmarks.

I did tests on memcpy_perf_test. Set threshold to 1024.
But when smaller than 1024 bytes, it costs 2~4 cycles more than the original.
Such as original is 10, right now is 12. Then the drop is 2/12=16%.
I don't know this kind of drop matters a lot or not.
And above 1024 bytes, the drop is almost 4% as I said before.

/Xiaoyun

  reply	other threads:[~2017-10-25 10:32 UTC|newest]

Thread overview: 87+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-26  7:41 [dpdk-dev] [PATCH v3 0/3] dynamic linking support Xiaoyun Li
2017-09-26  7:41 ` [dpdk-dev] [PATCH v3 1/3] eal/x86: run-time dispatch over memcpy Xiaoyun Li
2017-10-01 23:41   ` Ananyev, Konstantin
2017-10-02  0:12     ` Li, Xiaoyun
2017-09-26  7:41 ` [dpdk-dev] [PATCH v3 2/3] app/test: run-time dispatch over memcpy perf test Xiaoyun Li
2017-09-26  7:41 ` [dpdk-dev] [PATCH v3 3/3] efd: run-time dispatch over x86 EFD functions Xiaoyun Li
2017-10-02  0:08   ` Ananyev, Konstantin
2017-10-02  0:09     ` Li, Xiaoyun
2017-10-02  9:35     ` Ananyev, Konstantin
2017-10-02 16:13 ` [dpdk-dev] [PATCH v4 0/3] run-time Linking support Xiaoyun Li
2017-10-02 16:13   ` [dpdk-dev] [PATCH v4 1/3] eal/x86: run-time dispatch over memcpy Xiaoyun Li
2017-10-02 16:39     ` Ananyev, Konstantin
2017-10-02 23:10       ` Li, Xiaoyun
2017-10-03 11:15         ` Ananyev, Konstantin
2017-10-03 11:39           ` Li, Xiaoyun
2017-10-03 12:12             ` Ananyev, Konstantin
2017-10-03 12:23               ` Li, Xiaoyun
2017-10-02 16:13   ` [dpdk-dev] [PATCH v4 2/3] app/test: run-time dispatch over memcpy perf test Xiaoyun Li
2017-10-02 16:13   ` [dpdk-dev] [PATCH v4 3/3] efd: run-time dispatch over x86 EFD functions Xiaoyun Li
2017-10-02 16:52     ` Ananyev, Konstantin
2017-10-03  8:15       ` Li, Xiaoyun
2017-10-03 11:23         ` Ananyev, Konstantin
2017-10-03 11:27           ` Li, Xiaoyun
2017-10-03 14:59   ` [dpdk-dev] [PATCH v5 0/3] run-time Linking support Xiaoyun Li
2017-10-03 14:59     ` [dpdk-dev] [PATCH v5 1/3] eal/x86: run-time dispatch over memcpy Xiaoyun Li
2017-10-03 14:59     ` [dpdk-dev] [PATCH v5 2/3] app/test: run-time dispatch over memcpy perf test Xiaoyun Li
2017-10-03 14:59     ` [dpdk-dev] [PATCH v5 3/3] efd: run-time dispatch over x86 EFD functions Xiaoyun Li
2017-10-04 17:56     ` [dpdk-dev] [PATCH v5 0/3] run-time Linking support Ananyev, Konstantin
2017-10-04 22:33       ` Li, Xiaoyun
2017-10-04 22:58     ` [dpdk-dev] [PATCH v6 " Xiaoyun Li
2017-10-04 22:58       ` [dpdk-dev] [PATCH v6 1/3] eal/x86: run-time dispatch over memcpy Xiaoyun Li
2017-10-05  9:37         ` Ananyev, Konstantin
2017-10-05  9:38           ` Ananyev, Konstantin
2017-10-05 11:19           ` Li, Xiaoyun
2017-10-05 11:26             ` Richardson, Bruce
2017-10-05 11:26             ` Li, Xiaoyun
2017-10-05 12:12               ` Ananyev, Konstantin
2017-10-04 22:58       ` [dpdk-dev] [PATCH v6 2/3] app/test: run-time dispatch over memcpy perf test Xiaoyun Li
2017-10-04 22:58       ` [dpdk-dev] [PATCH v6 3/3] efd: run-time dispatch over x86 EFD functions Xiaoyun Li
2017-10-05  9:40         ` Ananyev, Konstantin
2017-10-05 10:23           ` Li, Xiaoyun
2017-10-05 12:33       ` [dpdk-dev] [PATCH v7 0/3] run-time Linking support Xiaoyun Li
2017-10-05 12:33         ` [dpdk-dev] [PATCH v7 1/3] eal/x86: run-time dispatch over memcpy Xiaoyun Li
2017-10-09 17:47           ` Thomas Monjalon
2017-10-13  1:06             ` Li, Xiaoyun
2017-10-13  7:21               ` Thomas Monjalon
2017-10-13  7:30                 ` Li, Xiaoyun
2017-10-13  7:31                 ` Ananyev, Konstantin
2017-10-13  7:36                   ` Thomas Monjalon
2017-10-13  7:41                     ` Li, Xiaoyun
2017-10-05 12:33         ` [dpdk-dev] [PATCH v7 2/3] app/test: run-time dispatch over memcpy perf test Xiaoyun Li
2017-10-05 12:33         ` [dpdk-dev] [PATCH v7 3/3] efd: run-time dispatch over x86 EFD functions Xiaoyun Li
2017-10-05 13:24         ` [dpdk-dev] [PATCH v7 0/3] run-time Linking support Ananyev, Konstantin
2017-10-09 17:40         ` Thomas Monjalon
2017-10-13  0:58           ` Li, Xiaoyun
2017-10-13  9:01         ` [dpdk-dev] [PATCH v8 " Xiaoyun Li
2017-10-13  9:01           ` [dpdk-dev] [PATCH v8 1/3] eal/x86: run-time dispatch over memcpy Xiaoyun Li
2017-10-13  9:28             ` Thomas Monjalon
2017-10-13 10:26               ` Ananyev, Konstantin
2017-10-17 21:24             ` Thomas Monjalon
2017-10-18  2:21               ` Li, Xiaoyun
2017-10-18  6:22                 ` Li, Xiaoyun
2017-10-19  2:45                   ` Li, Xiaoyun
2017-10-19  6:58                     ` Thomas Monjalon
2017-10-19  7:51                       ` Li, Xiaoyun
2017-10-19  8:33                         ` Thomas Monjalon
2017-10-19  8:50                           ` Li, Xiaoyun
2017-10-19  8:59                             ` Ananyev, Konstantin
2017-10-19  9:00                             ` Thomas Monjalon
2017-10-19  9:29                               ` Bruce Richardson
2017-10-20  1:02                                 ` Li, Xiaoyun
2017-10-25  6:55                                   ` Li, Xiaoyun
2017-10-25  7:25                                     ` Thomas Monjalon
2017-10-29  8:49                                       ` Thomas Monjalon
2017-11-02 10:22                                         ` Wang, Zhihong
2017-11-02 10:44                                           ` Thomas Monjalon
2017-11-02 10:58                                             ` Li, Xiaoyun
2017-11-02 12:15                                               ` Thomas Monjalon
2017-11-03  7:47                                             ` Yao, Lei A
2017-10-25  8:50                                     ` Ananyev, Konstantin
2017-10-25  8:54                                       ` Li, Xiaoyun
2017-10-25  9:00                                         ` Thomas Monjalon
2017-10-25 10:32                                           ` Li, Xiaoyun [this message]
2017-10-25  9:14                                         ` Ananyev, Konstantin
2017-10-13  9:01           ` [dpdk-dev] [PATCH v8 2/3] app/test: run-time dispatch over memcpy perf test Xiaoyun Li
2017-10-13  9:01           ` [dpdk-dev] [PATCH v8 3/3] efd: run-time dispatch over x86 EFD functions Xiaoyun Li
2017-10-13 13:13           ` [dpdk-dev] [PATCH v8 0/3] run-time Linking support Thomas Monjalon

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