[dpdk-dev] [PATCH v2 5/5] app/testpmd: enable empty polls in burst stats

[Honnappa Nagarahalli]

Hi Ferruh,
	Thanks for the review comments

<snip>

> Subject: Re: [PATCH v2 5/5] app/testpmd: enable empty polls in burst stats
> 
> On 6/26/2020 11:09 PM, Honnappa Nagarahalli wrote:
> > The number of empty polls provides information about available CPU
> > head room in the presence of continuous polling.
> 
> +1 to have it, it can be useful.
> 
> >
> > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
> > Reviewed-by: Phil Yang <phil.yang at arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
> > Tested-by: Phil Yang <phil.yang at arm.com>
> > Tested-by: Ali Alnubani <alialnu at mellanox.com>
> 
> <...>
> 
> >  	/*
> >  	 * First compute the total number of packet bursts and the
> >  	 * two highest numbers of bursts of the same number of packets.
> >  	 */
> >  	total_burst = 0;
> > -	burst_stats[0] = burst_stats[1] = burst_stats[2] = 0;
> > -	pktnb_stats[0] = pktnb_stats[1] = pktnb_stats[2] = 0;
> > +	memset(&burst_stats, 0x0, sizeof(burst_stats));
> > +	memset(&pktnb_stats, 0x0, sizeof(pktnb_stats));
> > +
> >  	for (nb_pkt = 0; nb_pkt < MAX_PKT_BURST; nb_pkt++) {
> >  		nb_burst = pbs->pkt_burst_spread[nb_pkt];
> > -		if (nb_burst == 0)
> > -			continue;
> >  		total_burst += nb_burst;
> > -		if (nb_burst > burst_stats[0]) {
> > -			burst_stats[1] = burst_stats[0];
> > -			pktnb_stats[1] = pktnb_stats[0];
> > +
> > +		/* Show empty poll stats always */
> > +		if (nb_pkt == 0) {
> >  			burst_stats[0] = nb_burst;
> >  			pktnb_stats[0] = nb_pkt;
> 
> just a minor issue but this assignment is not needed.
The empty poll stats are being shown always (even if there were no empty polls). The check 'nb_pkts == 0' indicates that the burst stats are for empty polls. Hence this assignment is required. But, this can be moved out of the loop to provide clarity. I will do that.

> 
> > -		} else if (nb_burst > burst_stats[1]) {
> > +			continue;
> > +		}
> > +
> > +		if (nb_burst == 0)
> > +			continue;
> 
> again another minor issue, can have this check above 'nb_pkt == 0', to prevent
> unnecssary "burst_stats[0] = nb_burst;" assignment if "nb_burst == 0".
The empty polls are always shown, even if there were 0% empty polls.

> 
> <...>
> 
> Reviewed-by: Ferruh Yigit <ferruh.yigit at intel.com>