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From: Neil Horman <nhorman@tuxdriver.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH 4/4] lib/librte_eal: Optimized memcpy in arch/x86/rte_memcpy.h for both SSE and AVX platforms
Date: Tue, 20 Jan 2015 14:16:24 -0500	[thread overview]
Message-ID: <20150120191624.GJ18449@hmsreliant.think-freely.org> (raw)
In-Reply-To: <20150120091538.4c3a1363@urahara>

On Tue, Jan 20, 2015 at 09:15:38AM -0800, Stephen Hemminger wrote:
> On Mon, 19 Jan 2015 09:53:34 +0800
> zhihong.wang@intel.com wrote:
> 
> > Main code changes:
> > 
> > 1. Differentiate architectural features based on CPU flags
> > 
> >     a. Implement separated move functions for SSE/AVX/AVX2 to make full utilization of cache bandwidth
> > 
> >     b. Implement separated copy flow specifically optimized for target architecture
> > 
> > 2. Rewrite the memcpy function "rte_memcpy"
> > 
> >     a. Add store aligning
> > 
> >     b. Add load aligning based on architectural features
> > 
> >     c. Put block copy loop into inline move functions for better control of instruction order
> > 
> >     d. Eliminate unnecessary MOVs
> > 
> > 3. Rewrite the inline move functions
> > 
> >     a. Add move functions for unaligned load cases
> > 
> >     b. Change instruction order in copy loops for better pipeline utilization
> > 
> >     c. Use intrinsics instead of assembly code
> > 
> > 4. Remove slow glibc call for constant copies
> > 
> > Signed-off-by: Zhihong Wang <zhihong.wang@intel.com>
> 
> Dumb question: why not fix glibc memcpy instead?
> What is special about rte_memcpy?
> 
> 
Fair point.  Though, does glibc implement optimized memcpys per arch?  Or do
they just rely on the __builtin's from gcc to get optimized variants?

Neil

  reply	other threads:[~2015-01-20 19:16 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-19  1:53 [dpdk-dev] [PATCH 0/4] DPDK memcpy optimization 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 [this message]
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         ` [dpdk-dev] [snabb-devel] " Luke Gorrie
2015-01-29  3:42 ` [dpdk-dev] " Fu, JingguoX

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