Re: [dpdk-dev] [PATCH v2 1/2] mbuf: provide rte_pktmbuf_alloc_bulk API

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

On Thu, Dec 17, 2015 at 03:42:19PM +0000, Ananyev, Konstantin wrote:
> 
> 
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Yuanhan Liu
> > Sent: Thursday, December 17, 2015 6:41 AM
> > To: Xie, Huawei
> > Cc: dev@dpdk.org
> > Subject: Re: [dpdk-dev] [PATCH v2 1/2] mbuf: provide rte_pktmbuf_alloc_bulk API
> > 
> > > +{
> > > +	unsigned idx = 0;
> > > +	int rc;
> > > +
> > > +	rc = rte_mempool_get_bulk(pool, (void **)mbufs, count);
> > > +	if (unlikely(rc))
> > > +		return rc;
> > > +
> > > +	switch (count % 4) {
> > > +	while (idx != count) {
> > 
> > Well, that's an awkward trick, putting while between switch and case.
> > 
> > How about moving the whole switch block ahead, and use goto?
> > 
> > 	switch (count % 4) {
> > 	case 3:
> > 		goto __3;
> > 		break;
> > 	case 2:
> > 		goto __2;
> > 		break;
> > 	...
> > 
> > 	}
> > 
> > It basically generates same instructions, yet it improves the
> > readability a bit.
> 
> I am personally not a big fun of gotos, unless it is totally unavoidable.
> I think switch/while construction is pretty obvious these days.

To me, it's not. (well, maybe I have been out for a while :(

> For me the original variant looks cleaner,

I agree with you on that. But it sacrifices code readability a bit.
If two pieces of code generates same instructions, but one is cleaner
(shorter), another one is more readable, I'd prefer the later.

> so my vote would be to stick with it.

Okay. And anyway, above is just a suggestion, and I'm open to other
suggestions.

	--yliu