From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: "Wang, Zhihong" <zhihong.wang@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
Thomas Monjalon <thomas.monjalon@6wind.com>
Subject: Re: [dpdk-dev] [PATCH] vhost: optimize vhost memcpy
Date: Mon, 5 Dec 2016 18:37:09 +0800 [thread overview]
Message-ID: <20161205103709.GL24403@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <8F6C2BD409508844A0EFC19955BE09414E7FF22D@SHSMSX103.ccr.corp.intel.com>
On Mon, Dec 05, 2016 at 10:27:00AM +0000, Wang, Zhihong wrote:
> > I like this function a lot, since it's really simple and straightforward!
> > Moreover, it performs better.
> >
> > But, I don't quite like how this function is proposed:
> >
> > - rte_movX are more like internal help functions that should be used only
> > in corresponding rte_memcpy.h file.
> >
> > - It's a good optimization, however, it will not benefit for other use
> > cases, though vhost is the most typical case here.
> >
> > - The optimization proves to be good for X86, but think there is no
> > guarantee it may behave well for other platforms, say ARM.
> >
> > I still would suggest you to go this way: move this function into x86's
> > rte_memcpy.h and call it when the data is well aligned.
>
>
> Do you mean to add something like rte_memcpy_aligned() in
> lib/librte_eal/common/include/generic/rte_memcpy.h?
Yes, but this one is not supposed to be exported as a public API.
It should be called inside rte_memcpy (when data is well aligned).
In this way, only rte_memcpy is exposed, and nothing else should
be changed.
--yliu
>
> I thought of this way before, and didn't choose it because it requires
> changes in eal. But it would be a clean solution, I'd certainly like
> to implement it this way if people are okay with it.
>
>
> Thanks
> Zhihong
>
>
> >
> > --yliu
next prev parent reply other threads:[~2016-12-05 10:36 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-02 1:19 Zhihong Wang
2016-12-02 10:30 ` Thomas Monjalon
2016-12-05 8:27 ` Yuanhan Liu
2016-12-05 10:27 ` Wang, Zhihong
2016-12-05 10:37 ` Yuanhan Liu [this message]
2016-12-07 6:11 ` Wang, Zhihong
2016-12-07 1:31 ` [dpdk-dev] [PATCH v2] eal: optimize aligned rte_memcpy Zhihong Wang
2016-12-08 0:55 ` Yao, Lei A
2016-12-08 2:18 ` Yuanhan Liu
2017-01-17 15:08 ` Thomas Monjalon
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