I don’t know much about networking sorry. I’m building a client / server where the server streams a lot of data to the client and I’m trying to maximise throughput (through TCP). If I run both client and server I get pretty high throughput. However, when going over the network card (the 2 machines are … Read more
We are running ubuntu 11.04 with 2.6.38-13-generic kernel on Intel(R) Xeon(R) CPU E5620 @ 2.40GHz with 48 GB RAM dedicated server with Hardware RAID. top command output is showing many kernel threads running on different cores. thread number ksoftirqd – 16 (one on each core) kworker – 35 migration – 16 (one on each core) … Read more
I’m running Debian and I’m running into an IRQ problem, two cards that generate a lot of IRQ interrupts are sharing the same IRQ (16). I found on the HP Bios an option that states “allow OS to trip IRQ”, I enable it, but how do I actually change the IRQ from the OS? Answer … Read more
I’m reading a book on Windows Internals and there’s something I don’t understand: “The kernel handles software interrupts either as part of hardware interrupt handling or synchronously when a thread invokes kernel functions related to the software interrupt.” So does this mean that software interrupts or exceptions will only be handled under these conditions: a. … Read more
Our server recently had a very bad day, and one of the indicators/reasons seems to be that RES interrupts are douple their normal value, but what does this mean ? (other interrupts: LOC+100%, eth1/TLB +30%) Answer They are “Rescheduling interrupts”, as far as I can tell they’re caused when the kernel moves a process between … Read more
I had a problem with CPU7 overload. I found that it was caused by the eth0 interrupts, as you can see on below cat /proc/interrupts. I’m using 2.6.35.2 kernel and Quad-Core AMD Opteron(tm) Processor 2354. I would like that interrupt were supported by all cores so I’ve tried to echo ff > /proc/irq/16/smp_affinity but it’s … Read more
Currently I am seeing a lot of CPU usage on events/1 and I was wanting to know how to figure out what is causing that? cat /proc/interrupts CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7 CPU8 CPU9 CPU10 CPU11 CPU12 CPU13 CPU14 CPU15 0: 575075290 0 0 0 0 0 0 0 0 0 0 … Read more
I’m not sure if I’m at the right place to ask this but I’m learning about operating systems and I can’t find any info on this. I read that interrupts are created when a call is made in user mode that requests a system service. But I can’t find the reason why this happens. I’m … Read more
I have a centos vm and I am trying to distribute the softirqs across multiple cores. I have modified the smp_affinity_list from 3 to 0-3 but instead of balancing the interrupts, it just moved the interrupts to cpu 0. is there a way at all to balance the interrupts? I am using CentOS Linux release … Read more
I have a VPN server with Intel X710 and Xeon E5-2630 v4. Debian 10. Based on accel-ppp, pptp protocol. Single SFP interface, two vlans. Problem – interrupts are not evenly distributed across queues. In the first queue, more than 10 times more interrupts come than the rest. Because of this, after running set_irq_affinity -x all … Read more
