RE: [PATCH net-next 2/3] net: mvpp2: adjust gso stop wake thresholds

[Yan Markman]

I will make this tomorrow.
Thanks for attention!
Best regards
Yan Markman
Tel. 05-44732819


-----Original Message-----
From: Antoine Tenart [mailto:antoine.tenart@xxxxxxxxxxx] 
Sent: Tuesday, February 27, 2018 7:14 PM
To: David Miller <davem@xxxxxxxxxxxxx>
Cc: antoine.tenart@xxxxxxxxxxx; Yan Markman <ymarkman@xxxxxxxxxxx>; mw@xxxxxxxxxxxx; Stefan Chulski <stefanc@xxxxxxxxxxx>; thomas.petazzoni@xxxxxxxxxxxxxxxxxx; gregory.clement@xxxxxxxxxxxxxxxxxx; miquel.raynal@xxxxxxxxxxxxxxxxxx; Nadav Haklai <nadavh@xxxxxxxxxxx>; maxime.chevallier@xxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: [PATCH net-next 2/3] net: mvpp2: adjust gso stop wake thresholds

Hi David,

On Tue, Feb 27, 2018 at 11:13:06AM -0500, David Miller wrote:
> From: Antoine Tenart <antoine.tenart@xxxxxxxxxxx>
> > From: Yan Markman <ymarkman@xxxxxxxxxxx>
> > -#define MVPP2_MAX_TSO_SEGS		300
> > +#define MVPP2_MAX_TSO_SEGS		100
> >  #define MVPP2_MAX_SKB_DESCS		(MVPP2_MAX_TSO_SEGS * 2 + MAX_SKB_FRAGS)
> >  
> >  /* Dfault number of RXQs in use */
> > @@ -5810,7 +5810,7 @@ static int mvpp2_txq_init(struct mvpp2_port *port,
> >  		txq_pcpu->tso_headers = NULL;
> >  
> >  		txq_pcpu->stop_threshold = txq->size - MVPP2_MAX_SKB_DESCS;
> > -		txq_pcpu->wake_threshold = txq_pcpu->stop_threshold / 2;
> > +		txq_pcpu->wake_threshold = txq_pcpu->stop_threshold - 100;
> >  
> 
> This number 100 is a magic constant.  If it is related to 
> MVPP2_MAX_TSO_SEGS, please use that define.  Otherwise define a new 
> one which is descriptive.

I agree. I'll ask Yan about it and update if possible.

Thanks!
Antoine

--
Antoine Ténart, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com