Re: relationship between cpu_affinity and Packet RX Processing

2013-03-30 Thread Rami Rosen
Hi, Stay tuned as I intend to put on the web an expanded document, including documentations about kernel internals (besides networking). Regards, Rami Rosen http://ramirose.wix.com/ramirosen On Fri, Mar 29, 2013 at 4:36 PM, Kumar amit mehta gmate.a...@gmail.com wrote: On Tue, Mar 26, 2013 at

Re: relationship between cpu_affinity and Packet RX Processing

2013-03-30 Thread Paulo Petruzalek
Thanks a lot for this document Rami! I'm starting to study the kernel and it will greatly help me to figure out how to dig into the source code. Looking forward for the expanded version as well! Best regards, Paulo iPhoneから送信 30/03/2013 05:16、Rami Rosen roszenr...@gmail.com のメッセージ: Hi,

Re: relationship between cpu_affinity and Packet RX Processing

2013-03-29 Thread Kumar amit mehta
On Tue, Mar 26, 2013 at 09:31:01PM +0200, Rami Rosen wrote: Hi, 1) You can be sure that it does not use more than one rx queue. You can find more info about RX queues in http://media.wix.com/ugd//295986_4ef6dbdf11fd0a7f74f09741b4b5b2ee.pdf (I wrote it, a shameless plug...) 2) Does

Re: relationship between cpu_affinity and Packet RX Processing

2013-03-29 Thread Kumar amit mehta
On Tue, Mar 26, 2013 at 09:31:01PM +0200, Rami Rosen wrote: Hi, 1) You can be sure that it does not use more than one rx queue. You can find more info about RX queues in http://media.wix.com/ugd//295986_4ef6dbdf11fd0a7f74f09741b4b5b2ee.pdf Thank you so much for sharing this.

relationship between cpu_affinity and Packet RX Processing

2013-03-26 Thread Kumar amit mehta
Hi All, I was reading some stuff on interrupts and irq lines today and I thought I'll expermient with the network rx path. To start with, I've a Virtual Machine running 3.8 linux kernel. My machine has 4 CPU cores, network (eth) interface is driven by pcnet_32 AMD driver and is tied to IRQ line

Re: relationship between cpu_affinity and Packet RX Processing

2013-03-26 Thread Arlie Stephens
Hi Amit, On Mar 26 2013, Kumar amit mehta wrote: Hi All, I was reading some stuff on interrupts and irq lines today and I thought I'll expermient with the network rx path. To start with, I've a Virtual Machine running 3.8 linux kernel. My machine has 4 CPU cores, network (eth) interface

Re: relationship between cpu_affinity and Packet RX Processing

2013-03-26 Thread Rami Rosen
Hi, Kumar, 1) Regarding rx queues: what does ls /sys/class/net/eth0/queues show ? 2) can you try setting affinity for working only with CPU3 and see what happens after some traffic is sent by cat /proc/interrupts? regards, Rami Rosen http://ramirose.wix.com/ramirosen On Tue, Mar 26, 2013 at

Re: relationship between cpu_affinity and Packet RX Processing

2013-03-26 Thread Kumar amit mehta
On Tue, Mar 26, 2013 at 11:45:55AM -0700, Arlie Stephens wrote: I don't know for sure what linux does, but the NICs I've seen with multiple queues tend to select queues by hashing incoming packets based on source IP, sourse port, destination IP, destination port and (if TCP) protocol.

Re: relationship between cpu_affinity and Packet RX Processing

2013-03-26 Thread Kumar amit mehta
On Tue, Mar 26, 2013 at 08:35:56PM +0200, Rami Rosen wrote: 1) Regarding rx queues: what does ls /sys/class/net/eth0/queues show ? $ ls /sys/class/net/eth0/queues rx-0 tx-0 2) can you try setting affinity for working only with CPU3 and see what happens after some traffic is sent by cat

Re: relationship between cpu_affinity and Packet RX Processing

2013-03-26 Thread Rami Rosen
Hi, 1) You can be sure that it does not use more than one rx queue. You can find more info about RX queues in http://media.wix.com/ugd//295986_4ef6dbdf11fd0a7f74f09741b4b5b2ee.pdf (I wrote it, a shameless plug...) 2) Does the irqbalance service, which is common in some distros, is running ?