On Sat, Sep 15, 2007 at 04:29:39PM -0700, David Schwartz wrote: > > > Hello, > > > > is it expected that application sending 8900bytes datagram > > through 10Gbps NIC > > utilizes CPU to 100% and similarly the receiver also utilizes CPU to 100%. > > Is it something wrong or this is quite OK? > > > > (The box is dual single core Opteron 2.4GHz with Myricom 10GE NIC.) > > It's extremely hard to understand what it is that you're saying. Perhaps if > I explain the two things I first thought when you posted this, it will > explain why your post is vague: > > 1) *Any* task will use the CPU to 100% while it's running. Even if you ask > the computer to add 1 to 1, while it's doing that add for you, the task is > using 100% of the CPU. > > 2) If you ask the CPU to do any task over and over again as quickly as it > can, and it has nothing else to do, that task will get 100% of the CPU? > > So what are you really asking?
I think he means that his application saturates the 10Gbps NIC with 8900 bytes datagrams and it consumes 100% of the CPU while doing this, and it's the same on the receiver side. I'm not surprized at all, considering that it means around 140kpps, or pauses of about 7 microseconds between each frame. Those pauses are too short to do anything else, resulting in the task to appear as taking 100% CPU. But IMHO, that does not mean that the machine is saturated; If the task had more work to do between each datagram, it would possibly be done. Same if it had to send shorter frames twice as fast. Willy - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/