packet drop with intel gigabit / marwell gigabit

[dima]

> i increased hz from 2000 to 5000, now the packet loss is decreased
> from 5-6% to 0.6-0,8% !!!
> huge improve!
> should i increase hz more?

You can. But remember that higher HZ values spend more CPU time for task switching. So if the hardware is used for something more than only network workload you would get performance penalty in other areas. A faster CPU would be a useful option in your case (with a proper HZ increase)

It seems that this card has very small buffer size. And it's nothing you can do about that.

> 
> 
> ----- Original Message ----- 
> From: "OxY" <oxy at field.hu>
> To: "Chuck Swiger" <cswiger at mac.com>
> Cc: <freebsd-performance at freebsd.org>
> Sent: Saturday, March 18, 2006 2:23 PM
> Subject: Re: packet drop with intel gigabit / marwell gigabit
> 
> 
> > currently i use HZ=2000
> > here's the output of netstat -i, -s, and vmstat -i :
> > (currently i am uploading on the gigabit with ftp, 3 threads)
> >
> > Field root# vmstat -i
> > interrupt                          total       rate
> > irq0: clk                       27503959       1993
> > irq1: atkbd0                           1          0
> > irq3: fxp0                             2          0
> > irq7:                                146          0
> > stray irq7                           146          0
> > irq8: rtc                        1765569        127
> > irq10: atapci1                   2807786        203
> > irq11: atapci0                    475039         34
> > irq13: npx0                            1          0
> > irq14: ata0                           99          0
> > Total                           32552748       2359
> >
> > Field root# netstat -i
> > Name    Mtu Network       Address              Ipkts Ierrs    Opkts Oerrs 
> > Coll
> > fxp0   1500 <Link#1>      00:a0:c9:8d:79:68 13163545     0 21899372     1 
> > 0
> > fxp0   1500 195.38.96.64/ field                  141     - 
> > 6     -     -
> > em0    1500 <Link#2>      00:0e:0c:a2:ac:42 68644181     4 66793904     0 
> > 0
> > em0    1500 195.38.96.64/ field             211255811     - 
> >      -     -
> > lo0   16384 <Link#3>                        129622061     0 129622061 
> > 0 0
> >
> > netstat -s is here:
> > http://field.hu/netstat.txt
> >
> > ----- Original Message ----- 
> > From: "Chuck Swiger" <cswiger at mac.com>
> > To: "OxY" <oxy at field.hu>
> > Cc: <freebsd-performance at freebsd.org>
> > Sent: Saturday, March 18, 2006 1:37 PM
> > Subject: Re: packet drop with intel gigabit / marwell gigabit
> >
> >
> >> OxY wrote:
> >>> yeah, i googled these settings, but i put them back to default then!
> >>> i measured iperf performance, and it showed that the packet drop is
> >>> depending on the system load..
> >>
> >> If you are using the normal interrupt-driven configuration, you should 
> >> look at
> >> netstat -i, -s, and vmstat -i.  If you're turning on device polling, you 
> >> ought
> >> to retry your testing at higher HZ (try 2000 or 5000):
> >>
> >>   echo 'kern.hz="2000"' >> /boot/loader.conf
> >>
> >> -- 
> >> -Chuck
> >
> > _______________________________________________
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> > http://lists.freebsd.org/mailman/listinfo/freebsd-performance
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> 
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