Search Results

Search found 11543 results on 462 pages for 'kernel module'.

Page 307/462 | < Previous Page | 303 304 305 306 307 308 309 310 311 312 313 314  | Next Page >

• Tool to diagonalize large matrices

  - by Xodarap

  I want to compute a diffusion kernel, which involves taking exp(b*A) where A is a large matrix. In order to play with values of b, I'd like to diagonalize A (so that exp(A) runs quickly). My matrix is about 25k x 25k, but is very sparse - only about 60k values are non-zero. Matlab's "eigs" function runs of out memory, as does octave's "eig" and R's "eigen." Is there a tool to find the decomposition of large, sparse matrices? Dunno if this is relevant, but A is an adjacency matrix, so it's symmetric, and it is full rank.

  Read the article

• best method of turning millions of x,y,z positions of particles into visualisation

  - by Griff

  I'm interested in different algorithms people use to visualise millions of particles in a box. I know you can use Cloud-In-Cell, adaptive mesh, Kernel smoothing, nearest grid point methods etc to reduce the load in memory but there is very little documentation on how to do these things online. i.e. I have array with: x,y,z 1,2,3 4,5,6 6,7,8 xi,yi,zi for i = 100 million for example. I don't want a package like Mayavi/Paraview to do it, I want to code this myself then load the decomposed matrix into Mayavi (rather than on-the-fly rendering) My poor 8Gb Macbook explodes if I try and use the particle positions. Any tutorials would be appreciated.

  Read the article

• mounting without -o loop

  - by jumpinjoe

  Hi, I have written a dummy (ram disk) block device driver for linux kernel. When the driver is loaded, I can see it as /dev/mybd. I can successfully transfer data onto it using dd command, compare the copied data successfully. The problem is that when I create ext2/3 filesystem on it, I have to use -o loop option with the mount command. Otherwise mount fails with following result: mount: wrong fs type, bad option, bad superblock on mybd, missing codepage or helper program, or other error What could be the problem? Please help. Thanks.

  Read the article

• Any book that covers internals of recent versions of Unix OS

  - by claws

  This summer I'm getting into UNIX (mostly *BSD) development. I've graduate level knowledge about operating systems. I can also understand the code & read from here and there but the thing is I want to make most of my time. Reading books are best for this. From my search I found that these two books The Design and Implementation of the 4.4 BSD Operating System (1996) "Unix Internals: The New Frontiers" by Uresh Vahalia (1996) (See here for 2nd edition) are like established books on UNIX OS internals. But the thing is these books are pretty much outdated. So, Is there any recent books that covers internals of recent Unix OS? How about books on other Unix operating systems? They seem to be recent than above books but how close are they to OpenBSD/FreeBSD? Solaris 10 and OpenSolaris Kernel Architecture, 2 edition (July 20, 2006) HP-UX 11i Internals (February 1, 2004) I really don't prefer HP-UX as its not open source.

  Read the article

• Understanding top output in Linux

  - by Rayne

  Hi, I'm trying to determine the CPU usage of a program by looking at the output from Top in Linux. I understand that %us means userspace and %sy means system/kernel etc. But say I see 100%us. Does this mean that the CPU is really only doing useful work? What if a CPU is tied up waiting for resources that are not avaliable, or cache misses, would it also show up in the %us column, or any other column? Thank you.

  Read the article

• Strange behavior of for loop in scheduler_tick

  - by EpsilonVector

  I'm working on Linux kernel 2.4 (homework) and I inserted the following code into the scheduler_tick function: if (unlikely(rt_task(p)) || (p->policy==SCHED_PROD && p->time_ran>=p->process_expected_time)) { /* * RR tasks need a special form of timeslice management. * FIFO tasks have no timeslices. */ if ((p->policy == SCHED_RR || /*change*/p->policy==SCHED_PROD) && !--p->time_slice) { /*changes*/ if (p->policy == SCHED_PROD){ for (i=0; i<5000; i++){ printk("I'm leeching off SCHED_RR code! %d\n", i); } } /*end changes*/ The addition was added for debugging purposes. For some reason this causes very weird behavior: when a SCHED_PROD process triggers this code (and consequently the loop that follows) the loop counts to about 4600 normally, but then goes back to 4600 each time it counts to 4800, and gets stuck in an infinite loop. What's going on?? EDIT: The i variable is my own.

  Read the article

• compile error: The import xxxx cannot be resolved

  - by Zachary

  I am developing a Java project using Eclipse. The project uses another project called engine, which I have added in my project build-path. As I need to call a dabo class, called House, in one of my project class, named Window, I have used the following code as usual: import ee.asus.kernel.House; I got however the following error in compiling time: Exception in thread "main" java.lang.Error: Unresolved compilation problems: The import ee cannot be resolved House cannot be resolved to a type House cannot be resolved to a type House cannot be resolved to a type at main.ee.asus.GUI.FrameWindow.Window.<init>(Window.java:10) at main.ee.asus.GUI.StartApplication.main(StartApplication.java:13) It's worth to point out that my prject and the dabo project use the same directory/packages names. Does anyone have a clue where the error may be?

  Read the article

• How to make external Mathematica functions interruptible?

  - by Szabolcs

  I had an earlier question about integrating Mathematica with functions written in C++. This is a follow-up question: If the computation takes too long I'd like to be able to abort it using Evaluation Abort Evaluation. Which of the technologies suggested in the answers make it possible to have an interruptible C-based extension function? How can "interruptibility" be implemented on the C side? I need to make my function interruptible in a way which will corrupt neither it, nor the Mathematica kernel (i.e. it should be possible to call the function again from Mathematica after it has been interrupted)

  Read the article

• Is it safe to catch EXCEPTION_GUARD_PAGE

  - by Michael J

  Environment is VC++ 9 on various Win platforms (XP and later) I'm writing an unhandled exception handler. I have a vague recollection from my kernel days that it was bad to catch an EXCEPTION_GUARD_PAGE, as this was generated to tell the OS to enlarge the stack. My question is twofold: Can such an exception occur in user space? If so, is it safe to catch it? I'm not especially interested in doing anything with it. I just want to know if I need to put special code in to not catch it (as I'm catching everything at the moment).

  Read the article

• Customizing Log4j to filter PatternLayout

  - by JavaScriptDude

  Greetings, I have just starting migrating to WLS 10.x and have noticed that the thread name [%t] for WL is quite verbose and more informative than I need for my deployment needs. Ultimately, I only care about the thread ID but WL gives me this:    [ACTIVE] ExecuteThread: '0' for queue: 'weblogic.kernel.Default (self-tuning)' ~ Does anybody know if there is a way in log4j to write a custom filter that will allow me to override PatternLayout so I can parse the WLS Thread Name to just output the thread ID which in this case above is 0. I'd rather extend then customize as it makes upgrading libraries so much easier. Thanks :) - JsD

  Read the article

• Practicing buffer overflow attack in Ubuntu

  - by wakandan

  I am trying to learn to use buffer overflow attack in Ubuntu. Unfortunately, I cannot turn off Address Space Layout Randomization (ASLR) feature in this OS, which is turned on by default. I have tried some work around found in some fedora books: echo "0" > /proc/sys/kernel/randomize_va_space but for some reason the protection's still there. Please give me some suggestions. Thanks. [edit]Actually the above command was not successful, it said "Permission Denied", even with sudo. How can I fix that? [adding] I kept on getting segmetation fault error when it shows an address in stack. Is it related to non-executable stack in ubuntu :(?

  Read the article

• Sockets: RAW or STREAM

  - by user1415536

  May be the question is a bit stupid, but I'll ask it. I read a lot about raw sockets in network, have seen several examples. So, basically with raw sockets it's possible to build own stack of headers, like stack = IP + TCP/UDP + OWN_HEADER. My question is, is it possible to get some kind of ready frame of first two(IP + TCP/UDP) from the linux kernel and then just append own header to them? The operating system in question is linux and the language is C. I cannot find any function which can do such a thing, but may be I'm digging in a wrong direction.

  Read the article

• When to choose C over C++?

  - by aaa

  Hi. I have become a fond of C++ thanks to this website. Before, I programmed exclusively in C/Fortran, thinking that C++ was too slow (not anymore). Is there a reason to write new project purely in C? this is besides obvious things like low-level kernel/system components. What about intermediate things, like communication libraries, for example MPI? Is C still more portable than C++? I have messed with pretty exotic systems, like Cray, but have yet to see non-embedded system without C++. thanks

  Read the article

• How would I go about writing a Linux TTY sniffer?

  - by alienate

  For educational purposes (not that anyone should care the motivations behind such an exercise) I'd like to write a program that can read/write to/from alternate tty/pty's. I've read papers (from the 1990's) but can't employ the implementation they use, on modern UNIXes. I was hoping that someone had researched into this in the past, or at least, read documentation pertaining to it, that they could provide. I also wonder if (considering the fact that Linux doesn't have STREAMs) if this exercise must be done via a loadable kernel module? I have many questions and probably a misunderstanding of some of the fundamental ideologies that allow such objectives to be put in place, could someone help? :)

  Read the article

• What do you tell people your profession is? [closed]

  - by user110296

  My technical title is Member of the Technical Staff, and like you most of you, I design/write code for a living. I can never decide what to answer when someone asks what I do for a living? Software Developer? Software Engineer? [Kernel] Programmer? Computer Scientist? These all seem to have various bad connotations. I guess I like Software Engineer the best, but unfortunately this term has been coopted by people who don't actually code. I made the mistake of taking a 'Software Engineering' class, and realized that I definitely don't want to be associated with people who major in this. Probably this is too subjective, so feel free to community wiki it or whatever, but I think it is a valid question and I would like to hear what others have decided on and their reasoning.

  Read the article

• how to use NtCreateMutant(Zw) to create a mutex in C++

  - by Simon

  Hey i want to create a mutex with the kernel function NtCreateMutant. I did it like this: Handle hMutex; NTSTATUS ntMutex = NtOpenMutant(&hMutex,MUTEX_ALL_ACCESS,false); the NTSTATUS value that is returned: C0000024 STATUS_OBJECT_TYPE_MISMATCH hope someone can help me with calling NtOpenMutant the right way. With the windows API OpenMutex(..) its working just fine.. HANDLE hMutex; hMutex = OpenMutex(MUTEX_ALL_ACCESS, FALSE, "Name"); Hope someone can explain me how to use the nativ function :)

  Read the article

• What are the main reasons against the Windows Registry?

  - by dbemerlin

  If i want to develop a registry-like System for Linux, which Windows Registry design failures should i avoid? Which features would be absolutely necessary? What are the main concerns (security, ease-of-configuration, ...)? I think the Windows Registry was not a bad idea, just the implementation didn't fullfill the promises. A common place for configurations including for example apache config, database config or mail server config wouldn't be a bad idea and might improve maintainability, especially if it has options for (protected) remote access. I once worked on a kernel based solution but stopped because others said that registries are useless (because the windows registry is)... what do you think?

  Read the article

• How to extract a single function from a source file

  - by Adam Matan

  Hi, I'm working on a small academic research about extremely long and complicated functions in the Linux kernel. I'm trying to figure out if there is a good reason to write 600 or 800 lines-long functions. For that purpose, I would like to find a tool that can extract a function from a .c file, so I can run some automated tests on the function. For example, If I have the function cifs_parse_mount_options() within the file connect.c, I'm seeking a solution that would roughly work like: extract /fs/cifs/connect.c cifs_parse_mount_options and return the 523 lines of code(!) of the function, from the opening braces to the closing braces. Of course, any way of manipulating existing software packages like gcc to do that, would be most helpful too. Thanks, Udi EDIT : The answers to Regex to pull out C function prototype declarations? convinced me that matching function declaration by regex is far from trivial.

  Read the article

• Address of instruction causing SIGSEGV in external program

  - by karramba

  I want to get address of instruction that causes external program to SIGSEGV. I tried using ptrace for this, but I'm getting EIP from kernel space (probably default signal handler?). How GDB is able to get the correct EIP? Is there a way to make GDB provide this information using some API? edit: I don't have sources of the program, only binary executable. I need automation, so I can't simply use "run", "info registers" in GDB. I want to implement "info registers" in my own mini-debugger :)

  Read the article

• Increasing FD_SETSIZE

  - by user1633717

  I need to increase the FD_SETSIZE value from 1024 to 4096. I know it'd be better to use poll()/epoll() but I want to understand what are pros/cons. The main question is: have I to recompile glibc? I read several thread where the change of .h after changing FD_SETSIZE works recompiling only the user application. Reading the glibc code (and the kernel too), actually it seems to me that if I want to use select(), FD_* macro and so on, I have to recompile all because the size of fd_set is changed. At this point I have to recompile all not only my application because if in the system there is an another "common" application that uses select and friends, I could have problem. Am I right?

  Read the article

• C : Memory layout of C program execution

  - by pavun_cool

  Hi All , I wanted know how the kernel is providing memory for simple C program . For example : #include<stdio.h> #include<malloc.h> int my_global = 10 ; main() { char *str ; static int val ; str = ( char *) malloc ( 100 ) ; scanf ( "%s" , str ) ; printf( " val:%s\n",str ) ; } See, In this program I have used static , global and malloc for allocating dynamic memory So , how the memory lay out will be ... ? Any one give me url , which will have have details information about this process..

  Read the article

• Keeping track of dirty blocks on a block device

  - by mikeY

  I'm looking for a way to keep track of what blocks on a block device are modified after a point in time. How I eventually want to use this for is to keep two 2TB disks in sync, one which only comes online (connected through USB) once a month. Without knowing what blocks have been modified, I have to go through the whole 2TB every time. I'm using a recent GNU/Linux OS and have C and Python experience. I'm hoping to avoid writing kernel level code as I don't have any experience in that area whatsoever. My current theory is that there should be some hooks somewhere where my code can get called when a disk flush is performed. Any ideas?

  Read the article

• Start diving into large open source projetcs

  - by Vanangamudi

  How to start learning and reading the source of large and complex projects like Blender3D and Gimp, for instance. Since the developers busy improving it and there is no docs exist at present, how do we start developing and customizing these projects. Linux kernel deserve to have several books on its code, also these kind of project do deserve the same. And there are no unit tests available for this kind of projects. Say I'm going to read and understand the source code blender. How do I start. How to setup the development environment for developing the app? If it includes several dependencies, and assume that their source code also available how to setup this kind of inter-related, coherent source code to debug?

  Read the article

• Is Android IPC plumbing exposed in any official and/or supported way?

  - by mathrick

  I'm interested in knowing how much the IPC mechanisms are meant to be exposed to the outside world. That is, if I wanted to impersonate a dalvik VM instance without having my app actually written in Java, am I allowed to do so, or will the protocol change the next time I look away from the screen? If it's allowed, what are the stability guarantees or lack thereof? Is there anything like documentation, or am I supposed just to read the fine sources on android.git.kernel.org? The purpose of it all would be to write apps in !Java languages while retaining the ability to construct GUIs. I don't care or mind if the code is technically inside a dalvik process as a JNI callout, what I'm interested in is "if I'm really good at pretending I'm Java over the wire, can I do everything actual Java code can? Or is there something that's only available as Java bytecode and nothing else?"

  Read the article

• MPICH2 vs KERRYGHED

  - by user311906

  Hi All right now I am moving first steps in clustering. I installed MPICH2 on my Ubuntu at home and I have a silly question about it. For what I am reading right now it seems that it provides the capability of sending processes to other pcs. I went for this lib just because I set it up very quickly and easily. Compared to MPICH2 , do you know what is the advantage of having a different clustering system like KERRYGHED? It seems that these ones also provide this capability, but the Kernel must be rebuild, so I suppose that it is going to be faster. What other advantages are remarkable for a clustering system like this? Thanks

  Read the article

< Previous Page | 303 304 305 306 307 308 309 310 311 312 313 314  | Next Page >