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3
votes
2answers
2k views

Making a IRQ SMP Affinity change permanent

I have to change the smp_affinity of a interrupt permanently. The following code needs to be executed when the server reboots: echo "1" > /proc/irq/152/smp_affinity_list echo "2" > ...
1
vote
1answer
112 views

How does handling an interrupt affects a multi-threaded user space process?

Say, I put a breakpoint (int 3 from now on) somewhere in a user space process code. One of the threads hits the breakpoint... And what happens next? My judgement is: this is an interrupt, so it is ...
1
vote
1answer
302 views

What value is stored in linux xtime variable?

Whenever I print the value of /proc/interrupts the value of rtc0 in IRQ8 which is for RTC shows only 1 interrupt on CPU0. I have read that when booting the value of the xtime variable is stored from ...
0
votes
1answer
39 views

Cannot compile device tree blob due to missing node/label

I'm trying to create a petalinux image using the petalinux SDK. After I start a build I get an error when the process tries to build the system.dtb The error is "(phandle references): Reference to ...
2
votes
0answers
471 views

How to configure FreeBSD to run headless without hitting high interrupt rates?

When running headless (without monitor, keyboard, mouse attached) FreeBSD versions 8.2, 8.3, 9.0 and NetBSD version 5.0 has known issues (FreeBSD PR 156596, NetBSD 46596) to generate extremely high ...
2
votes
0answers
121 views

Which counter generates timer interrupts?

I did a iotop to observe the interrupts on my computer. This is the interrupt shown most often. 0 [PIC-edge time] 247 Ints/s (max: 389) I believe it's the timer interrupt, well since ...
2
votes
0answers
700 views

“Remote function call interrupts” (CAL in /proc interrupts). What is it?

I'm running a test program which generates a large number of threads and asynchronous I/O. I'm seeing very high counts of these interrupts in /proc/interrupts, the program cannot scale beyond a ...
1
vote
0answers
139 views

What is the difference between Local timer interrupts and the timer?

When I do cat /proc/interrupts on my multicore x86_64 desktop PC (kernel 3.16) I see this: 0: 16 0 IO-APIC-edge timer LOC: 529283 401319 Local timer interrupts ...
1
vote
0answers
70 views

How does an X86 Linux system maintain the system time, when no NTP etc. is in play?

When an x86 Linux system is powered up and running, how does it keep track of software time? E.g. is it incrementing a software counter based on hardware interrupts from the RTC, or is there some ...
1
vote
0answers
266 views

Which softirq will execute if interrupt is generated on same line: preempted or new softirq?

Following is the sequence of events: interrupt generated at line 1. line 1 disable. ISR executed. Set sofirq bit 1 line 1 enable. softirq executes and suddenly interrupts come at line 1. softirq ...
0
votes
0answers
17 views

Stack pointer of the interrupt stack

Linux kernel has separate stacks for user mode and kernel mode process and also some special stacks. One of this special stacks is interrupt stack with the size 16 kilobytes placed in the ...
0
votes
0answers
43 views

default cpu affinity

On a CentOS 6 system with 32 cores, what could make all processes run under core 0 only? This is a system running nothing but a few stunnel processes actively. This is not a system we would set IRQ ...
0
votes
0answers
67 views

keyboard still working after calling free_irq(1, NULL);

I'm developing a kernel module which free the IRQ number 1 in order to disable the keyboard in Intel architectures. according to wikipedia the IRQ 1 is used for keyboard. but after building and ...
0
votes
0answers
214 views

Cannot change CPU affinity on 3.13 kernel for eth0 interrupts

We are running 3.13 kernel (Ubuntu 14.04) on an IBM x3550 servers. I think I may have found a bug changing IRQ affinity for eth0 internet interface, that corresponds to IRQ 43 on this device. ...
0
votes
0answers
225 views

Tunnel Win7 guest in VirtualBox through Tor running on Host

I have windows 7 running as a Guest in Virtualbox on my machine with ArchLinux as a Host. I want to redirect all the traffic from my Guest through Tor. For that I want to use a "Anonymizing Middlebox" ...