on a project I am working on, we are seeing out-of-order issues in certain circumstances on a SMP system when we are reading a UDP stream from the network. We can see it arrives from the network in order by sniffing off a hub connected between the sender and receiver. However sometimes it appears to arrive out of order when read from the...
I was reading the concept of OSX Services and it seemed very cool to me to have utilities like Dictionary, highlight-text-and-open-in-browser and a million other services that provide functionality based on what the user is currently doing. I have heard it mention that this mechanism is more similar to how pipes work in *nix, rather tha...
Hello, I am trying to understand the virtio mechanism in linux. I read that the kick function will notify the host side about the newly published buffers. I am looking especially at virtio_net.Once a packet is ready for transmission the kick function is called here. From here i traced the call and i think it goes to this. From here whe...
I have trouble to find the kernel API to enable some qdisc policies "tc" utility run from user-space. I found the modules in net/sched/sch_*.c but I'm not sure how to use them. For instance, if I want to enable TBF, should I do something like the following in my code? static struct Qdisc_ops tbf_qdisc_ops __read_mostly = { .ne...
I know that the qemu-kvm does the device emulation stuff in KVM. Is the qemu-kvm being executed in the userspace of the host? So when a kick function is encountered, it exits the VM through a hypercall into the hypervisor, then the hypervisor hand over to qemu-kvm in host userspace. Next after doing the needed things, the qemu-kvm transi...
How the Linux drivers interact with the host devices through the Android Emulator? I mean for instance how a virtual sound device driver, compiled for ARM and running inside of the Emulator communicates with the actual speaker on the computer. I heard that you need to use a special kernel image when running on top of the Emulator, so I ...
I just wrote a RTC driver for an NXP RTC chip on my board, it works great. This chip also has some battery backed RAM that I'd like to make available to a user space application. The RTC framework doesn't support this. It's only 512 bytes but I'm tossed between doing a seekable CHAR driver or a full blown BLOCK driver. I've never don...
Hi all, I am doing a script in which I change MAC address of interface in linux machine. But when I change the MAC address of the interface it generates an RARP packet (to get an IP address for the new MAC which is assigned). But this is not desirable in my scheme of things. I do not want the RARP to be generated. Can you guys suggest m...
Hello, i have an problem with modprobe command...i compiled the hello world module and inserted using "insmod" command...and its working..when i see "lsmod" its in that list...but when i insert this module using "modprobe" i am getting the FATAL error....that is root@okapi:/home/ravi# modprobe ./hello.ko FATAL: Module ./hello.ko not f...
Hi, The question is in the title =) ...
I am getting this message at step 6 of the instructions from this wiki: http://wiki.cyanogenmod.com/index.php/Building_from_source#Prepare_Kernel_From_Source Input: make ARCH=arm CROSS_COMPILE=CCOMPILER oldconfig Error Message: make: * No rule to make target 'oldconfig'. Stop. can someone help? ...
I am an old hand with hardware and device drivers and used much earlier Linux versions for hardware control. I am recently back in the game of Linux and device control using embedded processing and have discovered a lot has changed in the Linux world (for the better). However, I am struggling with a hardware control issue involving a ver...
Hi Guys, I have a piece of C code which with a chunk of memory(static array) can mimic file operations (It has APIs similar to fopen/fclose etc). So, any code that is compiled with this mimicking FileSystem can use these APIs as a FileSystem for all their needs :) But I was wondering, if its possible somehow to register these APIs with...
Hello, I am trying to profile my software (in Linux) with oprofile. My software consists of both userspace and kernel module. First my doubt is what does the --separate=kernel option do? What will be the difference when running without that option? I did try to see it but couldn't find any difference. Could you please post an example? C...
I was studying the Kernel Architecture and its programming to get the idea about Kernel. I know C programming but the structures and pointers mentioned in kernel code are going over my head. Like below int irq = regs.orig_eax & 0xff; asmlinkage int handle_IRQ_event(unsigned int irq, struct pt_regs *regs, ...
How do the Linux kernel developers test their code locally and after they have it committed? Do they use some kind of unit testing, build automation? test plans? ...
Hi, I wish to know what are the methods exist to check the Health of a process. Considering that on a system 10000 process are running and you have to make sure that in case any of these process goes down we need to make the process UP. ...
I'm trying to track down a kernel binary; is there a way to determine the version (build string) of a Linux 'uImage' binary? Running strings uImage piped into various trailing grep statements leads me to think I'm dealing with a compressed image... ...
i have ubuntu installed on the lenovo s10e netbook. i am not sure if this is related to the issue. i am new to source builds so i would appreciate some direction. i followed instructions on cyanogen's wiki (http://wiki.cyanogenmod.com/index.php/Building_from_source) i am stuck on the last step of 'Building CyanogenMod' after starting th...
This should be simple. Yet, it's giving me Hell. Problem I have compiled the latest kernel and when I reboot my box, it generates a kernel panic related to the filesystem. Question How do I get the new kernel to recognize the VMWare filesystem? There must be some setting somewhere that lets the Linux installation know that the "hard ...