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47 views

What is the source of the interrupt count in /proc/interrupts

I have a system that should receive an interrupt from a digital I/O card at 10Hz. Every so often the CPU usage will ramp up to about 60%. When I examine /proc/interrupts the count for interrupt ...
2
votes
1answer
100 views

Interrupts are confined to only CPU0 Core why?

Why interrupts are confined to CPU0, rather than using other cores that are available? Only for LOC: I could see the interrupts being distributed to other cores why it's not happening for eth0 and ...
2
votes
1answer
35 views

Events/1 and Server Interrupts

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 ...
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0answers
224 views

ksoftirqd causes very high cpu usage - server is sometimes completely unusable

the ksoftirqd process on my root (Ubuntu 12.04 x64 with kernel 3.11.6) causes occasionally a very high usage of the first cpu core (sometimes only 5 minutes, then 30 minutes long, ... it feels just ...
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1answer
162 views

Tracing down High Linux Load - HDD at fault or too many interrupts ? (ksoftirqd Time 437:44.13)

Server Stats: "cat /proc/version" Output Linux version 2.6.18-308.24.1.el5 (mockbuild@builder17.centos.org) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-52)) #1 SMP Tue Dec 4 17:43:34 EST 2012 ...
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0answers
101 views

Can't update smp_affinity

As part of the experiments that we are running to optimize the performance of the applications on our Linux box we are trying to assign all the network interrupts to a single cpu core. Unfortunately, ...
2
votes
1answer
116 views

How does a NIC send a hardware interrupt? [closed]

Some context. A few weeks ago, a NIC was replaced on a box without much troubleshooting to find a clear resolution to the problem. A senior administrator got into a small tiff with an entry-level ...
2
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0answers
48 views

High Interrupts and DPC in Windows after reboot

We have seen this several times in Win 2003 R2 32bit, XenApp 4.5 server where we have to reboot them to get rid of the problem. Sometimes more than once. We've had this issue on both smaller virtual ...
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0answers
100 views

Softirq has raisen without reason

Monitoring munin stats I found that on CPU's graph there was softirq value increased. What might be the reason? Currently I am experiencing problems with mysql cpu consumption. But how those things ...
7
votes
2answers
2k views

CPU0 is swamped with eth1 interrupts

I've got an Ubuntu VM, running inside Ubuntu-based Xen XCP. It hosts a custom FCGI-based HTTP service, behind nginx. Under load from ab the first CPU core is saturated, and the rest is under-loaded. ...
2
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0answers
306 views

Disabling IRQ#16 when removing DVI cable [closed]

I have a computer running with a Blackmagic Decklink card and a usbscreen. The problem i'm having is somethimes a irq conflict occurs and the OS disables irq16 witch both the decklink card and the usb ...
2
votes
1answer
387 views

Linux Kernel IRQ Routing with irqbalance / kernel options

I'm trying to get my Xen Dom0 distributing the irqs in an smp enviroment. As far as I know there are 2 Options: Use irqbalance Configure the kernel without cpu hotplug support My System is Debian ...
4
votes
1answer
2k views

Software Interrupts CPU time is high and keeps growing

My system is a Debian 6.0.3 x86_64 box w/kernel 2.6.32-5-openvz-amd64, it hosts a number of OpenVZ containers. I have recently migrated from LXC/newer kernel from backports repo to the stable OpenVZ ...
-1
votes
2answers
371 views

Can it be because of any Kernel Bugs?specifically spin lock

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 ...
-3
votes
1answer
150 views

Can a large number of network hardware interrupts cause a machine to be underutilized?

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 ...
7
votes
2answers
3k views

How to ban hardware interrupts with IRQBALANCE_BANNED_CPUS on Ubuntu?

I would like to ban interrupts from certain CPUs. I heard about the IRQBALANCE_BANNED_CPUS option. I see irqbalance is running in the background of my machine. Where do I go to edit and how do I ...
2
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0answers
116 views

CPU load inhibits interrupts on Linux

I have an Ubuntu box with 3.2 kernel, CPU with 2 cores and CAN (Controller Area Network) card based on SJA1000 controller attached via PCI bus. I'm testing receive capabilities of the card. It can ...
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3answers
2k views

Linux Interrupts Issue

Is there a simple way to determine if interrupts are a performance issue? I have the following from cat /proc/interrupts but really don't have a history of this server so I don't know if this could ...
2
votes
1answer
490 views

High interrupts, sometimes freezes

We have a Win 2003 R2 TS (x86) which has some "bad days". I have not been collecting data on this myself until just now, but it seems most of the time it runs fine, but some days we see high CPU ...
0
votes
1answer
860 views

What's the difference between hardware and software interrupt? [closed]

I'm gonna sketch my understanding of both. I've googled around but i'm not sure about my knowledge. Please correct me! Hardware interrupt is generated by the operation system event scheduler to ...
0
votes
1answer
268 views

Irregular interrupts balance in AMD Opetron Quad-Core

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 ...
4
votes
1answer
269 views

BSD 50% interrupt utilization in irq0/clock

On OpenBSD on an Atom 450, with HPET configured in the BIOS and not, also with Hyperthreading/ACPI on-off, nothing seems to make a difference. Here's my vmstat -iz # vmstat 2 procs memory ...
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5answers
5k views

What network loads require NIC polling vs interrupts?

Does anyone have some data or basic calculations that can answer when frame coalescing (NAPI) is required and when a single interrupt per frame is sufficient? My hardware: IBM BladeServer HS22, ...
2
votes
2answers
2k views

ethernet smp_affinity vs /proc/interrupts vs /sys/class/net/ethX/device

My goal is to configure our CentOS ("free" RHEL) 5.x servers for custom low-latency network programs. I would like to experiment with binding ethernet NIC interrupt handling to the same CPU on which ...
4
votes
1answer
7k views

NAPI vs Adaptive Interrupts

Could anyone please explain how two following technologies are used to mitigate interrupt overhead under high networking load? Adaptive-rx/Adaptive-tx, and NAPI; I would appreciate an answer that ...
2
votes
1answer
894 views

Distribute IP packets accross different NIC queues with MSI (Message Signalled Interrupts)

NetXtreme II BCM5709 Gigabit Ethernet NIC supports MSI feature (Message Signaled Interrupts) and it has 8 queues. Each queue has its own Interrupt handler in /proc/interrupts. What I am trying to ...
5
votes
3answers
5k views

How can I find out what is causing interrupts on Windows?

Occasionally I come across servers (Windows 2003 and 2008) with high processor % interrupt time. Is there a way to see what program or device is causing the interrupts?
0
votes
1answer
445 views

What are RES interrupts (from Munin)

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%, ...
0
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2answers
229 views

kernel software trap handling

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 ...
9
votes
1answer
9k views

What's the cause of high LOC interrupts?

I'm seeing huge spikes in LOC interrupts - around 4 million per second, what exactly is the LOC interrupt, what would cause these spikes, and what can I do about it? Here's a munin graph illustrating ...
0
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2answers
767 views

Alternative to /proc/interrupts

I would like to obtain information about interrupts assigned to my network cards. Is there any other way, than /proc/interrupts?
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2answers
898 views

NIC interface names in /proc/interrupts

When I look at /proc/interrupts: $ cat /proc/interrupts CPU0 CPU1 (...) 12: 4 0 IO-APIC-edge i8042 14: 145 65310875 IO-APIC-edge ide0 50: ...
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3answers
3k views

cause for high Interrupts and context switches

Hey guys, I have a quad core and I have spotted on munin (monitoring interrupts and context switches), that my interrupts and context switches spiked to 25k a second while the average was 250 for some ...
0
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2answers
970 views

Handle IRQ in Debian

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 ...
4
votes
3answers
7k views

What is “Interrupts” process and why it so loves my CPU?

I have windows XP SP3 on Intel Core Duo 2GHz. The "Interrupts" process, according to the Process Explorer, continuously take 30-40% CPU. Is it normal?