[ovs-discuss] CPU load caused by software interrupts

[Ben Pfaff]

Packet processing occurs in software interrupts, so this is unavoidable.

On Sat, Mar 01, 2014 at 10:26:59AM -0500, Sujayyendhiren RAMARAO SRINIVASAMURTHI wrote:
> Good day
> 
> Few more questions:
> - I have also observed that at high data rates OpenVSwitch CPU loading is
> about 50% and most of it is due to  software interrupts. Can that be
> reduced by changing any of the configuration parameters/Implementations ?
> 
> Regards
> Sujayyendhiren
> 
> On Fri, Feb 28, 2014 at 9:48 PM, Ben Pfaff <blp at nicira.com> wrote:
> 
> > On Fri, Feb 28, 2014 at 10:18:38AM -0500, Sujayyendhiren RAMARAO
> > SRINIVASAMURTHI wrote:
> > > *Design changes :*
> > >  As a research initiative, in OVS kernel module i have integrated a
> > lookup
> > > feature which takes about 16microseconds per data plane packet additional
> > > processing time. The implementation is quite stable.
> > >
> > > *General information :*
> > > - The OVS kernel module runs on a two core X-86 PC.
> > > - ovs-controller runs on another PC in the same LAN as the OVS PC.
> > > - Iperf source injects data packets onto the br0 bridge and br1 forwards
> > to
> > > iperf server. All of these in the same LAN.
> > >
> > >
> > > *Issues at high data rate:*
> > > (i) Beyond 280Mbps datarate packet losses are observed.
> >
> > There are 62500 16-us intervals in a second.  If your packets are 560
> > bytes long, then that's 280 Mbps.
> >
> 
> 
> 
> -- 
> Sujayyendhiren
> Graduate in Computer Science
> Rochester -NY

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