[dpdk-dev] [PATCH v3 0/5] vhost: optimize enqueue

[Thomas Monjalon]

2016-09-23 18:41, Jianbo Liu:
> On 23 September 2016 at 10:56, Wang, Zhihong <zhihong.wang at intel.com> wrote:
> .....
> > This is expected because the 2nd patch is just a baseline and all optimization
> > patches are organized in the rest of this patch set.
> >
> > I think you can do bottleneck analysis on ARM to see what's slowing down the
> > perf, there might be some micro-arch complications there, mostly likely in
> > memcpy.
> >
> > Do you use glibc's memcpy? I suggest to hand-crafted it on your own.
> >
> > Could you publish the mrg_rxbuf=on data also? Since it's more widely used
> > in terms of spec integrity.
> >
> I don't think it will be helpful for you, considering the differences
> between x86 and arm.
> So please move on with this patchset...

Jianbo,
I don't understand.
You said that the 2nd patch is a regression:
-       volatile uint16_t       last_used_idx;
+       uint16_t                last_used_idx;

And the overrall series lead to performance regression
for packets > 512 B, right?
But we don't know wether you have tested the v6 or not.

Zhihong talked about some improvements possible in rte_memcpy.
ARM64 is using libc memcpy in rte_memcpy.

Now you seem to give up.
Does it mean you accept having a regression in 16.11 release?
Are you working on rte_memcpy?