From: Luke Gorrie <luke@snabb.co>
To: "snabb-devel@googlegroups.com" <snabb-devel@googlegroups.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [snabb-devel] RE: [PATCH 0/4] DPDK memcpy optimization
Date: Tue, 27 Jan 2015 14:57:44 +0100 [thread overview]
Message-ID: <CAA2XHbeqZyK-RZEVh-+afwMWoL1ORg1aFvsmDaUeDNCTjmupcA@mail.gmail.com> (raw)
In-Reply-To: <F60F360A2500CD45ACDB1D700268892D0E76129D@SHSMSX101.ccr.corp.intel.com>
Hi again John,
Thank you for the patient answers :-)
Thank you for pointing this out: I was mistakenly testing your Sandy Bridge
code on Haswell (lacking -DRTE_MACHINE_CPUFLAG_AVX2).
Correcting that, your code is both the fastest and the smallest in my
humble micro benchmarking tests.
Looks like you have done great work! You probably knew that already :-) but
thank you for walking me through it.
The code compiles to 745 bytes of object code (smaller than glibc 2.20
memcpy) and cachebenches like this:
Memory Copy Library Cache Test
C Size Nanosec MB/sec % Chnge
------- ------- ------- -------
256 0.01 97587.60 1.00
384 0.01 97628.83 1.00
512 0.01 97613.95 1.00
768 0.01 147811.44 0.66
1024 0.01 158938.68 0.93
1536 0.01 168487.49 0.94
2048 0.01 174278.83 0.97
3072 0.01 156922.58 1.11
4096 0.01 145811.59 1.08
6144 0.01 157388.27 0.93
8192 0.01 149616.95 1.05
12288 0.01 149064.26 1.00
16384 0.01 107895.06 1.38
the key difference from my perspective is that glibc 2.20 memcpy
performance goes way down for >= 2048 bytes when they switch from vector
moves to string moves, while your code stays consistent.
I will take it for a spin in a real application.
Cheers,
-Luke
next prev parent reply other threads:[~2015-01-27 13:57 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-19 1:53 [dpdk-dev] " zhihong.wang
2015-01-19 1:53 ` [dpdk-dev] [PATCH 1/4] app/test: Disabled VTA for memcpy test in app/test/Makefile zhihong.wang
2015-01-19 1:53 ` [dpdk-dev] [PATCH 2/4] app/test: Removed unnecessary test cases in test_memcpy.c zhihong.wang
2015-01-19 1:53 ` [dpdk-dev] [PATCH 3/4] app/test: Extended test coverage in test_memcpy_perf.c zhihong.wang
2015-01-19 1:53 ` [dpdk-dev] [PATCH 4/4] lib/librte_eal: Optimized memcpy in arch/x86/rte_memcpy.h for both SSE and AVX platforms zhihong.wang
2015-01-20 17:15 ` Stephen Hemminger
2015-01-20 19:16 ` Neil Horman
2015-01-21 3:18 ` Wang, Zhihong
2015-01-25 20:02 ` Jim Thompson
2015-01-26 14:43 ` Wodkowski, PawelX
2015-01-27 5:12 ` Wang, Zhihong
2015-01-19 13:02 ` [dpdk-dev] [PATCH 0/4] DPDK memcpy optimization Neil Horman
2015-01-20 3:01 ` Wang, Zhihong
2015-01-20 15:11 ` Neil Horman
2015-01-20 16:14 ` Bruce Richardson
2015-01-21 3:44 ` Wang, Zhihong
2015-01-21 11:40 ` Bruce Richardson
2015-01-21 12:02 ` Ananyev, Konstantin
2015-01-21 12:38 ` Neil Horman
2015-01-23 3:26 ` Wang, Zhihong
2015-01-21 12:36 ` Marc Sune
2015-01-21 13:02 ` Bruce Richardson
2015-01-21 13:21 ` Marc Sune
2015-01-21 13:26 ` Bruce Richardson
2015-01-21 19:49 ` Stephen Hemminger
2015-01-21 20:54 ` Neil Horman
2015-01-21 21:25 ` Jim Thompson
2015-01-22 0:53 ` Stephen Hemminger
2015-01-22 9:06 ` Luke Gorrie
2015-01-22 13:29 ` Jay Rolette
2015-01-22 18:27 ` Luke Gorrie
2015-01-22 19:36 ` Jay Rolette
2015-01-22 18:21 ` EDMISON, Kelvin (Kelvin)
2015-01-27 8:22 ` Wang, Zhihong
2015-01-28 21:48 ` EDMISON, Kelvin (Kelvin)
2015-01-29 1:53 ` Wang, Zhihong
2015-01-23 6:52 ` Wang, Zhihong
2015-01-26 18:29 ` Ananyev, Konstantin
2015-01-27 1:42 ` Wang, Zhihong
2015-01-27 11:30 ` Ananyev, Konstantin
2015-01-27 12:19 ` Ananyev, Konstantin
2015-01-28 2:06 ` Wang, Zhihong
2015-01-25 14:50 ` Luke Gorrie
2015-01-26 1:30 ` Wang, Zhihong
2015-01-26 8:03 ` Luke Gorrie
2015-01-27 7:19 ` Wang, Zhihong
2015-01-27 13:57 ` Luke Gorrie [this message]
2015-01-29 3:42 ` Fu, JingguoX
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