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From: "Yang, Zhiyong" <zhiyong.yang@intel.com>
To: "Richardson, Bruce" <bruce.richardson@intel.com>
Cc: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
	Thomas Monjalon <thomas.monjalon@6wind.com>,
	"dev@dpdk.org" <dev@dpdk.org>,
	"yuanhan.liu@linux.intel.com" <yuanhan.liu@linux.intel.com>,
	"De Lara Guarch, Pablo" <pablo.de.lara.guarch@intel.com>
Subject: Re: [dpdk-dev] [PATCH 1/4] eal/common: introduce rte_memset on IA platform
Date: Fri, 16 Dec 2016 10:19:43 +0000	[thread overview]
Message-ID: <E182254E98A5DA4EB1E657AC7CB9BD2A3EB59F21@BGSMSX101.gar.corp.intel.com> (raw)
In-Reply-To: <20161215101242.GA125588@bricha3-MOBL3.ger.corp.intel.com>

Hi, Bruce:

> -----Original Message-----
> From: Richardson, Bruce
> Sent: Thursday, December 15, 2016 6:13 PM
> To: Yang, Zhiyong <zhiyong.yang@intel.com>
> Cc: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Thomas
> Monjalon <thomas.monjalon@6wind.com>; dev@dpdk.org;
> yuanhan.liu@linux.intel.com; De Lara Guarch, Pablo
> <pablo.de.lara.guarch@intel.com>
> Subject: Re: [dpdk-dev] [PATCH 1/4] eal/common: introduce rte_memset on
> IA platform
> 
> On Thu, Dec 15, 2016 at 06:51:08AM +0000, Yang, Zhiyong wrote:
> > Hi, Thomas, Konstantin:
> >
> > > -----Original Message-----
> > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Yang, Zhiyong
> > > Sent: Sunday, December 11, 2016 8:33 PM
> > > To: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Thomas
> > > Monjalon <thomas.monjalon@6wind.com>
> > > Cc: dev@dpdk.org; yuanhan.liu@linux.intel.com; Richardson, Bruce
> > > <bruce.richardson@intel.com>; De Lara Guarch, Pablo
> > > <pablo.de.lara.guarch@intel.com>
> > > Subject: Re: [dpdk-dev] [PATCH 1/4] eal/common: introduce
> rte_memset
> > > on IA platform
> > >
> > > Hi, Konstantin, Bruce:
> > >
> > > > -----Original Message-----
> > > > From: Ananyev, Konstantin
> > > > Sent: Thursday, December 8, 2016 6:31 PM
> > > > To: Yang, Zhiyong <zhiyong.yang@intel.com>; Thomas Monjalon
> > > > <thomas.monjalon@6wind.com>
> > > > Cc: dev@dpdk.org; yuanhan.liu@linux.intel.com; Richardson, Bruce
> > > > <bruce.richardson@intel.com>; De Lara Guarch, Pablo
> > > > <pablo.de.lara.guarch@intel.com>
> > > > Subject: RE: [dpdk-dev] [PATCH 1/4] eal/common: introduce
> > > > rte_memset on IA platform
> > > >
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: Yang, Zhiyong
> > > > > Sent: Thursday, December 8, 2016 9:53 AM
> > > > > To: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Thomas
> > > > > Monjalon <thomas.monjalon@6wind.com>
> > > > > Cc: dev@dpdk.org; yuanhan.liu@linux.intel.com; Richardson, Bruce
> > > > > <bruce.richardson@intel.com>; De Lara Guarch, Pablo
> > > > > <pablo.de.lara.guarch@intel.com>
> > > > > Subject: RE: [dpdk-dev] [PATCH 1/4] eal/common: introduce
> > > > > rte_memset on IA platform
> > > > >
> > > > extern void *(*__rte_memset_vector)( (void *s, int c, size_t n);
> > > >
> > > > static inline void*
> > > > rte_memset_huge(void *s, int c, size_t n) {
> > > >    return __rte_memset_vector(s, c, n); }
> > > >
> > > > static inline void *
> > > > rte_memset(void *s, int c, size_t n) {
> > > > 	If (n < XXX)
> > > > 		return rte_memset_scalar(s, c, n);
> > > > 	else
> > > > 		return rte_memset_huge(s, c, n); }
> > > >
> > > > XXX could be either a define, or could also be a variable, so it
> > > > can be setuped at startup, depending on the architecture.
> > > >
> > > > Would that work?
> > > > Konstantin
> > > >
> > I have implemented the code for  choosing the functions at run time.
> > rte_memcpy is used more frequently, So I test it at run time.
> >
> > typedef void *(*rte_memcpy_vector_t)(void *dst, const void *src,
> > size_t n); extern rte_memcpy_vector_t rte_memcpy_vector; static inline
> > void * rte_memcpy(void *dst, const void *src, size_t n) {
> >         return rte_memcpy_vector(dst, src, n); } In order to reduce
> > the overhead at run time, I assign the function address to var
> > rte_memcpy_vector before main() starts to init the var.
> >
> > static void __attribute__((constructor))
> > rte_memcpy_init(void)
> > {
> > 	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX2))
> > 	{
> > 		rte_memcpy_vector = rte_memcpy_avx2;
> > 	}
> > 	else if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE4_1))
> > 	{
> > 		rte_memcpy_vector = rte_memcpy_sse;
> > 	}
> > 	else
> > 	{
> > 		rte_memcpy_vector = memcpy;
> > 	}
> >
> > }
> > I run the same virtio/vhost loopback tests without NIC.
> > I can see the  throughput drop  when running choosing functions at run
> > time compared to original code as following on the same platform(my
> machine is haswell)
> > 	Packet size	perf drop
> > 	64 		-4%
> > 	256 		-5.4%
> > 	1024		-5%
> > 	1500		-2.5%
> > Another thing, I run the memcpy_perf_autotest,  when N= <128, the
> > rte_memcpy perf gains almost disappears When choosing functions at run
> > time.  For N=other numbers, the perf gains will become narrow.
> >
> How narrow. How significant is the improvement that we gain from having to
> maintain our own copy of memcpy. If the libc version is nearly as good we
> should just use that.
> 
> /Bruce

Zhihong sent a patch about rte_memcpy,  From the patch,  
we can see the optimization job for memcpy will bring obvious perf improvements
than glibc for DPDK.
http://www.dpdk.org/dev/patchwork/patch/17753/
git log as following:
This patch is tested on Ivy Bridge, Haswell and Skylake, it provides
up to 20% gain for Virtio Vhost PVP traffic, with packet size ranging
from 64 to 1500 bytes.

thanks
Zhiyong

  reply	other threads:[~2016-12-16 10:19 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-05  8:26 [dpdk-dev] [PATCH 0/4] eal/common: introduce rte_memset and related test Zhiyong Yang
2016-12-02 10:00 ` Maxime Coquelin
2016-12-06  6:33   ` Yang, Zhiyong
2016-12-06  8:29     ` Maxime Coquelin
2016-12-07  9:28       ` Yang, Zhiyong
2016-12-07  9:37         ` Yuanhan Liu
2016-12-07  9:43           ` Yang, Zhiyong
2016-12-07  9:48             ` Yuanhan Liu
2016-12-05  8:26 ` [dpdk-dev] [PATCH 1/4] eal/common: introduce rte_memset on IA platform Zhiyong Yang
2016-12-02 10:25   ` Thomas Monjalon
2016-12-08  7:41     ` Yang, Zhiyong
2016-12-08  9:26       ` Ananyev, Konstantin
2016-12-08  9:53         ` Yang, Zhiyong
2016-12-08 10:27           ` Bruce Richardson
2016-12-08 10:30           ` Ananyev, Konstantin
2016-12-11 12:32             ` Yang, Zhiyong
2016-12-15  6:51               ` Yang, Zhiyong
2016-12-15 10:12                 ` Bruce Richardson
2016-12-16 10:19                   ` Yang, Zhiyong [this message]
2016-12-19  6:27                     ` Yuanhan Liu
2016-12-20  2:41                       ` Yao, Lei A
2016-12-15 10:53                 ` Ananyev, Konstantin
2016-12-16  2:15                   ` Yang, Zhiyong
2016-12-16 11:47                     ` Ananyev, Konstantin
2016-12-20  9:31                       ` Yang, Zhiyong
2016-12-08 15:09       ` Thomas Monjalon
2016-12-11 12:04         ` Yang, Zhiyong
2016-12-27 10:04   ` [dpdk-dev] [PATCH v2 0/4] eal/common: introduce rte_memset and related test Zhiyong Yang
2016-12-27 10:04     ` [dpdk-dev] [PATCH v2 1/4] eal/common: introduce rte_memset on IA platform Zhiyong Yang
2016-12-27 10:04     ` [dpdk-dev] [PATCH v2 2/4] app/test: add functional autotest for rte_memset Zhiyong Yang
2016-12-27 10:04     ` [dpdk-dev] [PATCH v2 3/4] app/test: add performance " Zhiyong Yang
2016-12-27 10:04     ` [dpdk-dev] [PATCH v2 4/4] lib/librte_vhost: improve vhost perf using rte_memset Zhiyong Yang
2017-01-09  9:48     ` [dpdk-dev] [PATCH v2 0/4] eal/common: introduce rte_memset and related test Yang, Zhiyong
2017-01-17  6:24       ` Yang, Zhiyong
2017-01-17 20:14         ` Thomas Monjalon
2017-01-18  0:15           ` Vincent JARDIN
2017-01-18  2:42           ` Yang, Zhiyong
2017-01-18  7:42             ` Thomas Monjalon
2017-01-19  1:36               ` Yang, Zhiyong
2016-12-05  8:26 ` [dpdk-dev] [PATCH 2/4] app/test: add functional autotest for rte_memset Zhiyong Yang
2016-12-05  8:26 ` [dpdk-dev] [PATCH 3/4] app/test: add performance " Zhiyong Yang
2016-12-05  8:26 ` [dpdk-dev] [PATCH 4/4] lib/librte_vhost: improve vhost perf using rte_memset Zhiyong Yang
2016-12-02  9:46   ` Thomas Monjalon
2016-12-06  8:04     ` Yang, Zhiyong

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