[dpdk-dev] [PATCH v1 2/2] Test cases for rte_memcmp functions

[Thomas Monjalon]

2017-01-09 05:29, Wang, Zhihong:
> From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com]
> > 2016-06-07 11:09, Wang, Zhihong:
> > > From: Ravi Kerur [mailto:rkerur at gmail.com]
> > > > Zhilong, Thomas,
> > > >
> > > > If there is enough interest within DPDK community I can work on adding
> > support
> > > > for 'unaligned access' and 'test cases' for it. Please let me know either
> > way.
> > >
> > > Hi Ravi,
> > >
> > > This rte_memcmp is proved with better performance than glibc's in aligned
> > > cases, I think it has good value to DPDK lib.
> > >
> > > Though we don't have memcmp in critical pmd data path, it offers a better
> > > choice for applications who do.
> > 
> > Re-thinking about this series, could it be some values to have a rte_memcmp
> > implementation?
> 
> I think this series (rte_memcmp included) could help:
> 
>  1. Potentially better performance in hot paths.
> 
>  2. Agile for tuning.
> 
>  3. Avoid performance complications -- unusual but possible,
>     like the glibc memset issue I met while working on vhost
>     enqueue.
> 
> > What is the value compared to glibc one? Why not working on glibc?
> 
> As to working on glibc, wider design consideration and test
> coverage might be needed, and we'll face different release
> cycles, can we have the same agility? Also working with old
> glibc could be a problem.

Probably we need both: add the optimized version in DPDK while working
on a glibc optimization.
This strategy could be applicable to memcpy, memcmp and memset.