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From: Thomas Monjalon <thomas@monjalon.net>
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" <ophirmu@mellanox.com>
Subject: Re: [dpdk-dev] [PATCH v8 1/3] eal/x86: run-time dispatch over memcpy
Date: Thu, 19 Oct 2017 08:58:54 +0200	[thread overview]
Message-ID: <1661434.2yK3chXuTC@xps> (raw)
In-Reply-To: <B9E724F4CB7543449049E7AE7669D82F47FD6D@SHSMSX101.ccr.corp.intel.com>

19/10/2017 04:45, Li, Xiaoyun:
> Hi
> > > >
> > > > The significant change of this patch is to call a function pointer
> > > > for packet size > 128 (RTE_X86_MEMCPY_THRESH).
> > > The perf drop is due to function call replacing inline.
> > >
> > > > Please could you provide some benchmark numbers?
> > > I ran memcpy_perf_test which would show the time cost of memcpy. I ran
> > > it on broadwell with sse and avx2.
> > > But I just draw pictures and looked at the trend not computed the
> > > exact percentage. Sorry about that.
> > > The picture shows results of copy size of 2, 4, 6, 8, 9, 12, 16, 32,
> > > 64, 128, 192, 256, 320, 384, 448, 512, 768, 1024, 1518, 1522, 1536,
> > > 1600, 2048, 2560, 3072, 3584, 4096, 4608, 5120, 5632, 6144, 6656, 7168,
> > 7680, 8192.
> > > In my test, the size grows, the drop degrades. (Using copy time
> > > indicates the
> > > perf.) From the trend picture, when the size is smaller than 128
> > > bytes, the perf drops a lot, almost 50%. And above 128 bytes, it
> > > approaches the original dpdk.
> > > I computed it right now, it shows that when greater than 128 bytes and
> > > smaller than 1024 bytes, the perf drops about 15%. When above 1024
> > > bytes, the perf drops about 4%.
> > >
> > > > From a test done at Mellanox, there might be a performance
> > > > degradation of about 15% in testpmd txonly with AVX2.
> > 
> 
> I did tests on X710, XXV710, X540 and MT27710 but didn't see performance degradation.
> 
> I used command "./x86_64-native-linuxapp-gcc/app/testpmd -c 0xf -n 4 -- -I" and set fwd txonly. 
> I tested it on v17.11-rc1, then revert my patch and tested it again.
> Show port stats all and see the throughput pps. But the results are similar and no drop.
> 
> Did I miss something?

I do not understand. Yesterday you confirmed a 15% drop with buffers between
128 and 1024 bytes.
But you do not see this drop in your txonly tests, right?

> > Another thing, I will test testpmd txonly with intel nics and mellanox these
> > days.
> > And try adjusting the RTE_X86_MEMCPY_THRESH to see if there is any
> > improvement.
> > 
> > > > Is there someone else seeing a performance degradation?

  reply	other threads:[~2017-10-19  6:58 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 [this message]
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
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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