Search Results

Search found 36698 results on 1468 pages for 'old linux fan'.

Page 108/1468 | < Previous Page | 104 105 106 107 108 109 110 111 112 113 114 115  | Next Page >

  • Lock a mutex multiple times in the same thread

    - by Megacan
    Hi, I'm developing an application on an embedded linux OS (uClinux) and I need to be able to lock the mutex more than once (by the same thread). I have a mutex and a mutexattr defined and initialized as follows: pthread_mutexattr_t waiting_barcode_mutexattr; pthread_mutex_t waiting_barcode_mutex; pthread_mutexattr_init(&waiting_barcode_mutexattr); pthread_mutexattr_settype(&waiting_barcode_mutexattr, PTHREAD_MUTEX_RECURSIVE); pthread_mutex_init(&waiting_barcode_mutex, &waiting_barcode_mutexattr); But when I try to acquire the lock twice it blocks on the second lock: pthread_mutex_lock(&waiting_barcode_mutex); pthread_mutex_lock(&waiting_barcode_mutex); Am I initializing it wrong or is there a better way of accomplishing the same? Thanks in advance.

    Read the article

  • Which display manager for a non interactive Python app and mplayer?

    - by Matt
    I am developing an application that will run on Linux to run fullscreen all the time (no menus or trays or anything will be visible). The application is going to be developed in Python, not that that matters as far as the display manager, but what I am having a hard time with is choosing a display manager. I need something with the smallest possible footprint, that will let me run a graphical Python app and have an mplayer window at the same time, at widescreen resolutions (widescreen, 16:10,16:9, etc). Other than that, it doesn't need a lot of features, but the end footprint size is the most important thing I'll be looking at. What display manager would you recommend?

    Read the article

  • Introducing the Oracle Linux Playground yum repo

    - by wcoekaer
    We just introduced a new yum repository/channel on http://public-yum.oracle.com called the playground channel. What we started doing is the following: When a new stable mainline kernel is released by Linus or GregKH, we internally build RPMs to test it and do some QA work around it to keep track of what's going on with the latest development kernels. It helps us understand how performance moves up or down and if there are issues, we try to help look into them and of course send that stuff back upstream. Many Linux users out there are interested in trying out the latest features but there are some potential barriers to do this. (1) in general, you are looking at an upstream development distribution, which means that everything changes both in userspace(random applications) and kernel. Projects like Fedora are very useful and someone that wants to just see how the entire distribution evolves with all the changes, this is a great way to be current. A drawback here, though, is that if you have applications that are not part of the distribution, there's a lot of manual work involved or they might just not work because the changes are too drastic. The introduction of systemd is a good example. (2) when you look at many of our customers, that are interested in our database products or applications, the starting point of having a supported/certified userspace/distribution, like Oracle Linux, is a much easier way to get your feet wet in seeing what new/future Linux kernel enhancements could do. This is where the playground channel comes into play. When you install Oracle Linux 6 (which anyone can download and use from http://edelivery.oracle.com/linux), grab the latest public yum repository file http://public-yum.oracle.com/public-yum-ol6.repo, put it in /etc/yum.repos.d and enable the playground repo : [ol6_playground_latest] name=Latest mainline stable kernel for Oracle Linux 6 ($basearch) - Unsupported baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/playground/latest/$basearch/ gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 gpgcheck=1 enabled=1 Now, all you need to do : type yum update and you will be downloading the latest stable kernel which will install cleanly on Oracle Linux 6. Thus you end up with a stable Linux distribution where you can install all your software, and then download the latest stable kernel (at time of writing this is 3.6.7) without having to recompile a kernel, without having to jump through hoops. There is of course a big, very important disclaimer this is NOT for PRODUCTION use. We want to try and help make it easy for people that are interested, from a user perspective, where the Linux kernel is going and make it easy to install and use it and play around with new features. Without having to learn how to compile a kernel and without necessarily having to install a complete new distribution with all the changes top to bottom. So we don't or won't introduce any new userspace changes, this project really is around making it easy to try out the latest upstream Linux kernels in a very easy way on an environment that's stable and you can keep current, since all the latest errata for Oracle Linux 6 are published on the public yum repo as well. So one repository location for all your current changes and the upstream kernels. We hope that this will get more users to try out the latest kernel and report their findings. We are always interested in understanding stability and performance characteristics. As new features are going into the mainline kernel, that could potentially be interesting or useful for various products, we will try to point them out on our blogs and give an example on how something can be used so you can try it out for yourselves. Anyway, I hope people will find this useful and that it will help increase interested in upstream development beyond reading lkml by some of the more non-kernel-developer types.

    Read the article

  • Linux C++: Linker is outputting strange errors

    - by knight666
    Alright, here is the output I get: arm-none-linux-gnueabi-ld --entry=main -dynamic-linker=/system/bin/linker -rpath-link=/home/oem/android-ndk-r3/build/platforms/android-5/arch-arm/usr/lib -L/home/oem/android-ndk-r3/build/platforms/android-5/arch-arm/usr/lib -nostdlib -lstdc++ -lm -lGLESv1_CM -rpath=/home/oem/android-ndk-r3/build/platforms/android-5/arch-arm/usr/lib -rpath=../../YoghurtGum/lib/Android -L./lib/Android intermediate/Alien.o intermediate/Bullet.o intermediate/Game.o intermediate/Player.o ../../YoghurtGum/bin/YoghurtGum.a -o bin/Galaxians.android intermediate/Game.o: In function `Galaxians::Init()': /media/YoghurtGum/Tests/Galaxians/src/Game.cpp:45: undefined reference to `__cxa_end_cleanup' /media/YoghurtGum/Tests/Galaxians/src/Game.cpp:44: undefined reference to `__cxa_end_cleanup' intermediate/Game.o:(.ARM.extab+0x18): undefined reference to `__gxx_personality_v0' intermediate/Game.o: In function `Player::Update()': /media/YoghurtGum/Tests/Galaxians/src/Player.h:41: undefined reference to `__cxa_end_cleanup' intermediate/Game.o:(.ARM.extab.text._ZN6Player6UpdateEv[_ZN6Player6UpdateEv]+0x0): undefined reference to `__gxx_personality_v0' intermediate/Game.o:(.rodata._ZTIN10YoghurtGum4GameE[_ZTIN10YoghurtGum4GameE]+0x0): undefined reference to `vtable for __cxxabiv1::__class_type_info' intermediate/Game.o:(.rodata._ZTI6Player[_ZTI6Player]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info' intermediate/Game.o:(.rodata._ZTIN10YoghurtGum6EntityE[_ZTIN10YoghurtGum6EntityE]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info' intermediate/Game.o:(.rodata._ZTIN10YoghurtGum6ObjectE[_ZTIN10YoghurtGum6ObjectE]+0x0): undefined reference to `vtable for __cxxabiv1::__class_type_info' intermediate/Game.o:(.rodata._ZTI6Bullet[_ZTI6Bullet]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info' intermediate/Game.o:(.rodata._ZTI5Alien[_ZTI5Alien]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info' intermediate/Game.o:(.rodata+0x20): undefined reference to `vtable for __cxxabiv1::__si_class_type_info' ../../YoghurtGum/bin/YoghurtGum.a(Sprite.o):(.rodata._ZTIN10YoghurtGum16SpriteDataOpenGLE[_ZTIN10YoghurtGum16SpriteDataOpenGLE]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info' ../../YoghurtGum/bin/YoghurtGum.a(Sprite.o):(.rodata._ZTIN10YoghurtGum10SpriteDataE[_ZTIN10YoghurtGum10SpriteDataE]+0x0): undefined reference to `vtable for __cxxabiv1::__class_type_info' make: *** [bin/Galaxians.android] Fout 1 Here's an error I managed to decipher: intermediate/Game.o: In function `Galaxians::Init()': /media/YoghurtGum/Tests/Galaxians/src/Game.cpp:45: undefined reference to `__cxa_end_cleanup' /media/YoghurtGum/Tests/Galaxians/src/Game.cpp:44: undefined reference to `__cxa_end_cleanup' This is line 43 through 45: Assets::AddSprite(new Sprite("media\\ViperMarkII.bmp"), "ship"); Assets::AddSprite(new Sprite("media\\alien.bmp"), "alien"); Assets::AddSprite(new Sprite("media\\bat_ball.bmp"), "bullet"); So, what seems funny to me is that the first new is fine (line 43), but the second one isn't. What could cause this? intermediate/Game.o: In function `Player::Update()': /media/YoghurtGum/Tests/Galaxians/src/Player.h:41: undefined reference to `__cxa_end_cleanup' Another issue with new: Engine::game->scene_current->AddObject(new Bullet(m_X + 10, m_Y)); I have no idea where to begin with the other issues. These are my makefiles, They're a giant mess because I'm just trying to get it to work. Static library: # ====================================== # # # # YoghurtGum static library # # # # ====================================== # include ../YoghurtGum.mk PROGS = bin/YoghurtGum.a SOURCES = $(wildcard src/*.cpp) #$(YG_PATH_LIB)/libGLESv1_CM.so \ #$(YG_PATH_LIB)/libEGL.so \ YG_LINK_OPTIONS = -shared YG_LIBRARIES = \ $(YG_PATH_LIB)/libc.a \ $(YG_PATH_LIB)/libc.so \ $(YG_PATH_LIB)/libstdc++.a \ $(YG_PATH_LIB)/libstdc++.so \ $(YG_PATH_LIB)/libm.a \ $(YG_PATH_LIB)/libm.so \ $(YG_PATH_LIB)/libui.so \ $(YG_PATH_LIB)/liblog.so \ $(YG_PATH_LIB)/libGLESv2.so \ $(YG_PATH_LIB)/libcutils.so \ YG_OBJECTS = $(patsubst src/%.cpp, $(YG_INT)/%.o, $(SOURCES)) YG_NDK_PATH_LIB = /home/oem/android-ndk-r3/build/platforms/android-5/arch-arm/usr/lib all: $(PROGS) rebuild: clean $(PROGS) # remove all .o objects from intermediate and all .android objects from bin clean: rm -f $(YG_INT)/*.o $(YG_BIN)/*.a copy: acpy ../$(PROGS) $(PROGS): $(YG_OBJECTS) $(YG_ARCHIVER) -vq $(PROGS) $(YG_NDK_PATH_LIB)/crtbegin_static.o $(YG_NDK_PATH_LIB)/crtend_android.o $^ && \ $(YG_ARCHIVER) -vr $(PROGS) $(YG_LIBRARIES) $(YG_OBJECTS): $(YG_INT)/%.o : $(YG_SRC)/%.cpp $(YG_COMPILER) $(YG_FLAGS) -I $(GLES_INCLUDES) -c $< -o $@ Test game project: # ====================================== # # # # Galaxians # # # # ====================================== # include ../../YoghurtGum.mk PROGS = bin/Galaxians.android YG_COMPILER = arm-none-linux-gnueabi-g++ YG_LINKER = arm-none-linux-gnueabi-ld YG_PATH_LIB = ./lib/Android YG_LIBRARIES = ../../YoghurtGum/bin/YoghurtGum.a YG_PROGS = bin/Galaxians.android GLES_INCLUDES = ../../YoghurtGum/src ANDROID_NDK_ROOT = /home/oem/android-ndk-r3 NDK_PLATFORM_VER = 5 YG_NDK_PATH_LIB = $(ANDROID_NDK_ROOT)/build/platforms/android-$(NDK_PLATFORM_VER)/arch-arm/usr/lib YG_LIBS = -nostdlib -lstdc++ -lm -lGLESv1_CM #YG_COMPILE_OPTIONS = -g -rdynamic -Wall -Werror -O2 -w YG_COMPILE_OPTIONS = -g -Wall -Werror -O2 -w YG_LINK_OPTIONS = --entry=main -dynamic-linker=/system/bin/linker -rpath-link=$(YG_NDK_PATH_LIB) -L$(YG_NDK_PATH_LIB) $(YG_LIBS) SOURCES = $(wildcard src/*.cpp) YG_OBJECTS = $(patsubst src/%.cpp, intermediate/%.o, $(SOURCES)) all: $(PROGS) rebuild: clean $(PROGS) clean: rm -f intermediate/*.o bin/*.android $(PROGS): $(YG_OBJECTS) $(YG_LINKER) $(YG_LINK_OPTIONS) -rpath=$(YG_NDK_PATH_LIB) -rpath=../../YoghurtGum/lib/Android -L$(YG_PATH_LIB) $^ $(YG_LIBRARIES) -o $@ $(YG_OBJECTS): intermediate/%.o : src/%.cpp $(YG_COMPILER) $(YG_COMPILE_OPTIONS) -I ../../YoghurtGum/src/GLES -I ../../YoghurtGum/src -c $< -o $@ Any help would be appreciated.

    Read the article

  • Ubuntu on Thinkpad Edge 11/13/14/15

    - by lasseespeholt
    I think a community wiki on problems (and solutions) when installing Ubuntu (10.10) on a Thinkpad Edge 11 would be nice (because I just got one ;)). I'll contribute with my own problems and solutions, and hope others will join too. Thinkwiki entry for the Edge 11 Known problems: No wifi-driver, solution: answer #1, answer #2 Fan is loud, even though it's on auto. No solution. Thinkfan is a possible solution, but correction values for sensors should be supplied (mapping sensors to specific areas). Also, one sensor is between -100C and +100C - maybe some kind of deactivation would help. FN keys stop working: see below. No sound on headphones: see below.

    Read the article

  • Ubuntu on Thinkpad Edge 11

    - by lasseespeholt
    Hi, I think a community wiki on problems (and solutions) when installing Ubuntu (10.10) on a Thinkpad Edge 11 would be nice (because I just got one ;)). I'll contribute with my own problems and solutions, and hope others will join too. Thinkwiki entry for the Edge 11 Known problems: No wifi-driver, solution: answer #1, answer #2 Fan is load, even though it's on auto. No solution. Thinkfan is a possible solution, but correction values for sensors should be supplied (mapping sensors to specific areas). Also, one sensor is between -100C and +100C - maybe some kind of deactivation would help.

    Read the article

  • Upgrading PHP, MySQL old-passwords issue

    - by Rushyo
    I've inherited a Windows 2k3 server running an XAMPP-installation from the stone age. I needed to upgrade PHP to facilitate an upgrade to MediaWiki to facilitate a new MediaWiki extension (to facilitate some documentation to facilitate doing my job to facilitate getting paid to facilit... you get the idea). However... installing a new version of PHP resulted in PHP's MySQL libraries refusing to communicate using MySQL's 'old style' 152-bit passwords. Not a problem in theory. The MySQL installation is post-4.1, so it should have the functionality to upgrade the user's passwords from 152-bit to 328-bit (what a weird hashing algorithm...). I ran the following: SET PASSWORD = PASSWORD('foo'); on MySQL but querying: SELECT user, password FROM mysql.user; returned just the same password I started out with - 152-bit. Now... I suspect you're thinking 'AHA! old-passwords is on!'. Unfortunately it's not - I've disabled it in the configuration (explicitly set it to 0), made doubly sure I have an absolute reference to that configuration file and ensured the service isn't using the --old-passwords flag. The service was reset after each and every operation. So I went onto another system and generated the 328-bit hash on there, copying the hash over to the first MySQL instance. Unfortunately, that didn't work either (I did remember to FLUSH PRIVILEGES). The application error is: "'mysqlnd cannot connect to MySQL 4.1+ using the old insecure authentication. Please use an administration tool [...snip...] Is there anything else I can try to get PHP to recognise MySQL as not using the 'old insecure authentication'? MySQL seems to be stuck in 'old-passwords' mode and I can't get it out of it.

    Read the article

  • Linux Kernel - Red/Black Trees

    - by CodeRanger
    I'm trying to implement a red/black tree in Linux per task_struct using code from linux/rbtree.h. I can get a red/black tree inserting properly in a standalone space in the kernel such as a module but when I try to get the same code to function with the rb_root declared in either task_struct or task_struct-files_struct, I get a SEGFAULT everytime I try an insert. Here's some code: In task_struct I create a rb_root struct for my tree (not a pointer). In init_task.h, macro INIT_TASK(tsk), I set this equal to RB_ROOT. To do an insert, I use this code: rb_insert(&(current-fd_tree), &rbnode); This is where the issue occurs. My insert command is the standard insert that is documented in all RBTree documentation for the kernel: int my_insert(struct rb_root *root, struct mytype *data) { struct rb_node **new = &(root->rb_node), *parent = NULL; /* Figure out where to put new node */ while (*new) { struct mytype *this = container_of(*new, struct mytype, node); int result = strcmp(data->keystring, this->keystring); parent = *new; if (result < 0) new = &((*new)->rb_left); else if (result > 0) new = &((*new)->rb_right); else return FALSE; } /* Add new node and rebalance tree. */ rb_link_node(&data->node, parent, new); rb_insert_color(&data->node, root); return TRUE; } Is there something I'm missing? Some reason this would work fine if I made a tree root outside of task_struct? If I make rb_root inside of a module this insert works fine. But once I put the actual tree root in the task_struct or even in the task_struct-files_struct, I get a SEGFAULT. Can a root node not be added in these structs? Any tips are greatly appreciated. I've tried nearly everything I can think of.

    Read the article

  • Linux RFID reader HID Device not matching driver

    - by blietaer
    Hello, I got a RFID reader (GigaTek PCR330A-00) that is meant to be recognized under linux/windows as a (Human Interface Device) keyboard/USB. I hate to say this but it is working as a charm under Win7 but not "really" under Linux. Under Debian-like distros (x/k/Ubuntu, Debian,..), or Gentoo, or... I just can't have the device working at all: the device scan well (it has its USB 5V, so it is happy/beeping/blinking) something happened in the dmesg, but no immediate screen display of the RFID Tag code as expected (and seen under win7) Support is claiming it is ok under RHEL or SLED "enterprises" distros... and I must admit I saw it working under a RHEL4... I tried stealing the driver but did not succeed having my reader working... My question is thus double: 1./ How can I hack the kernel to add support to my device (simply register PID/VID?) ? 2./ What is different at all in a "enterprise" proprietary distro? how can I re-use it? Thank you for any hint/help. Cheers,

    Read the article

  • Synchronizing files between Linux servers, through FTP

    - by Daniel Magliola
    I have the following configuration of servers: 1 central linux server, a VPS 8 satellite linux servers, "crappy shared hostings" I have a bunch of files that I need to have in all servers. Right now i'm copying them everywhere manually, but I want to be able to copy them to the central server, and then have a scheduled process that runs every now and then and synchronizes them (only outwardly, no need to try to find "new" files in the satellite servers). There are a couple of catches though: I can't have any custom software in the satellite servers, or do strange command line things that'll auto connect to them and send the files directly. I know this is the way these kinds of things are normally done, but the satellite servers are crappy shared hosting ones where I have absolutely no control over anything. I need to send the files over FTP I also need to have, in my central server, a list of the files that are available in each of the satellite servers, to make sure they are ready before I send traffic to them. If I were to do this manually, the steps would be: get the list of files in a satellite server compare to my own, and send the files that are missing get the list of files again, and store it in my central database. I'd like to know what tools are out there that can alleviate as much of this as possible, first the syncing, and then the "getting the list of files available in the other server". I'm going to be doing everything from PHP, not sure if there are good tools to "use FTP from PHP", which i'm pretty sure i'll have to do for step 3 at least. Thanks in advance for any ideas! Daniel

    Read the article

  • Listing directories in Linux from C

    - by nunos
    I am trying to simulate linux command ls using linux api from c. Looking at the code it does make sense, but when I run it I get "stat error: No such file or directory". I have checked that opendir is working ok. I think the problem is in stat, which is returning -1 even though I think it should return 0. What am I missing? Thanks for your help. #include <stdio.h> #include <stdlib.h> #include <string.h> #include <dirent.h> #include <sys/stat.h> #include <errno.h> int main(int argc, char *argv[]) { DIR *dirp; struct dirent *direntp; struct stat stat_buf; char *str; if (argc != 2) { fprintf( stderr, "Usage: %s dir_name\n", argv[0]); exit(1); } if ((dirp = opendir( argv[1])) == NULL) { perror(argv[1]); exit(2); } while ((direntp = readdir( dirp)) != NULL) { if (stat(direntp->d_name, &stat_buf)==-1) { perror("stat ERROR"); exit(3); } if (S_ISREG(stat_buf.st_mode)) str = "regular"; else if (S_ISDIR(stat_buf.st_mode)) str = "directory"; else str = "other"; printf("%-25s - %s\n", direntp->d_name, str); } closedir(dirp); exit(0); }

    Read the article

  • F#, Linux and makefiles

    - by rwallace
    I intend to distribute an F# program as both binary and source so the user has the option of recompiling it if desired. On Windows, I understand how to do this: provide .fsproj and .sln files, which both Visual Studio and MSBuild can understand. On Linux, the traditional solution for C programs is a makefile. This depends on gcc being directly available, which it always is. The F# compiler can be installed on Linux and works under Mono, so that's fine so far. However, as far as I can tell, it doesn't create a scenario where fsc runs the compiler, instead the command is mono ...path.../fsc.exe. This is also fine, except I don't know what the path is going to be. So the full command to run the compiler in my case could be mono ~/FSharp-2.0.0.0/bin/fsc.exe types.fs tptp.fs main.fs -r FSharp.PowerPack.dll except that I'm not sure where fsc.exe will actually be located on the user's machine. Is there a way to find that out within a makefile, or would it be better to fall back on just explaining the above in the documentation and relying on the user to modify the command according to his setup?

    Read the article

  • linux new/delete, malloc/free large memory blocks

    - by brian_mk
    Hi folks, We have a linux system (kubuntu 7.10) that runs a number of CORBA Server processes. The server software uses glibc libraries for memory allocation. The linux PC has 4G physical memory. Swap is disabled for speed reasons. Upon receiving a request to process data, one of the server processes allocates a large data buffer (using the standard C++ operator 'new'). The buffer size varies depening upon a number of parameters but is typically around 1.2G Bytes. It can be up to about 1.9G Bytes. When the request has completed, the buffer is released using 'delete'. This works fine for several consecutive requests that allocate buffers of the same size or if the request allocates a smaller size than the previous. The memory appears to be free'd ok - otherwise buffer allocation attempts would eventually fail after just a couple of requests. In any case, we can see the buffer memory being allocated and freed for each request using tools such as KSysGuard etc. The problem arises when a request requires a buffer larger than the previous. In this case, operator 'new' throws an exception. It's as if the memory that has been free'd from the first allocation cannot be re-allocated even though there is sufficient free physical memory available. If I kill and restart the server process after the first operation, then the second request for a larger buffer size succeeds. i.e. killing the process appears to fully release the freed memory back to the system. Can anyone offer an explanation as to what might be going on here? Could it be some kind of fragmentation or mapping table size issue? I am thinking of replacing new/delete with malloc/free and use mallopt to tune the way the memory is being released to the system. BTW - I'm not sure if it's relevant to our problem, but the server uses Pthreads that get created and destroyed on each processing request. Cheers, Brian.

    Read the article

  • Port Win32 DLL hook to Linux

    - by peachykeen
    I have a program (NWShader) which hooks into a second program's OpenGL calls (NWN) to do post-processing effects and whatnot. NWShader was originally built for Windows, generally modern versions (win32), and uses both DLL exports (to get Windows to load it and grab some OpenGL functions) and Detours (to hook into other functions). I'm using the trick where Win will look in the current directory for any DLLs before checking the sysdir, so it loads mine. I have on DLL that redirects with this method: #pragma comment(linker, "/export:oldFunc=nwshader.newFunc) To send them to a different named function in my own DLL. I then do any processing and call the original function from the system DLL. I need to port NWShader to Linux (NWN exists in both flavors). As far as I can tell, what I need to make is a shared library (.so file). If this is preloaded before the NWN executable (I found a shell script to handle this), my functions will be called. The only problem is I need to call the original function (I would use various DLL dynamic loading methods for this, I think) and need to be able to do Detour-like hooking of internal functions. At the moment I'm building on Ubuntu 9.10 x64 (with the 32-bit compiler flags). I haven't been able to find much on Google to help with this, but I don't know exactly what the *nix community refers to it as. I can code C++, but I'm more used to Windows. Being OpenGL, the only part the needs modified to be compatible with Linux is the hooking code and the calls. Is there a simple and easy way to do this, or will it involve recreating Detours and dynamically loading the original function addresses?

    Read the article

  • Linux Scheduling Mechanism in 2.6.22?

    - by Mazen
    Hello, I'm doing some kind of performance evaluation using two different vanilla Linux kernels, 2.6.22 and 2.6.31, since I assume each of them uses a different scheduling mechanism: 2.6.22 uses the old O(1) scheduler, whilst 2.6.31 adopts the CFS. Could anybody confirm the correction of this assumption?

    Read the article

  • Linux C debugging library to detect memory corruptions

    - by calandoa
    When working sometimes ago on an embedded system with a simple MMU, I used to program dynamically this MMU to detect memory corruptions. For instance, at some moment at runtime, the foo variable was overwritten with some unexpected data (probably by a dangling pointer or whatever). So I added the additional debugging code : at init, the memory used by foo was indicated as a forbidden region to the MMU; each time foo was accessed on purpose, access to the region was allowed just before then forbidden just after; a MMU irq handler was added to dump the master and the address responsible of the violation. This was actually some kind of watchpoint, but directly self-handled by the code itself. Now, I would like to reuse the same trick, but on a x86 platform. The problem is that I am very far from understanding how is working the MMU on this platform, and how it is used by Linux, but I wonder if any library/tool/system call already exist to deal with this problem. Note that I am aware that various tools exist like Valgrind or GDB to manage memory problems, but as far as I know, none of these tools car be dynamically reconfigured by the debugged code. I am mainly interested for user space under Linux, but any info on kernel mode or under Windows is also welcome!

    Read the article

  • Building a custom Linux Live CD

    - by Mike Heinz
    Can anyone point me to a good tutorial on creating a bootable Linux CD from scratch? I need help with a fairly specialized problem: my firm sells an expansion card that requires custom firmware. Currently we use an extremely old live CD image of RH7.2 that we update with current firmware. Manufacturing puts the cards in a machine, boots off the CD, the CD writes the firmware, they power off and pull the cards. Because of this cycle, it's essential that the CD boot and shut down as quickly as possible. The problem is that with the next generation of cards, I have to update the CD to a 2.6 kernel. It's easy enough to acquire a pre-existing live CD - but those all are designed for showing off Linux on the desktop - which means they take forever to boot. Can anyone fix me up with a current How-To? Update: So, just as a final update for anyone reading this later - the tool I ended up using was "livecd-creator". My reason for choosing this tool was that it is available for RedHat-based distributions like CentOs, Fedora and RHEL - which are all distributions that my company supports already. In addition, while the project is very poorly documented it is extremely customizable. I was able to create a minimal LiveCD and edit the boot sequence so that it booted directly into the firmware updater instead of a bash shell. The whole job would have only taken an hour or two if there had been a README explaining the configuration file!

    Read the article

  • Changing default compiler in Linux, using SCons

    - by ereOn
    On my Linux platform, I have several versions of gcc. Under usr/bin I have: gcc34 gcc44 gcc Here are some outputs: $ gcc --version gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-48) $ gcc44 --version gcc44 (GCC) 4.4.0 20090514 (Red Hat 4.4.0-6) I need to use the 4.4 version of gcc however the default seems to the 4.1 one. I there a way to replace /usr/bin/gcc and make gcc44 the default compiler not using a symlink to /usr/bin/gcc44 ? The reason why I can't use a symlink is because my code will have to be shipped in a RPM package using mock. mock creates a minimal linux installation from scratch and just install the specified dependencies before compiling my code in it. I cannot customize this "minimal installation". Ideally, the perfect solution would be to install an official RPM package that replaces gcc with gcc44 as the default compiler. Is there such a package ? Is this even possible/good ? Additional information I have to use SCons (a make alternative) and it doesn't let me specify the binary to use for gcc. I will also accept any answer that will tell me how to specify the gcc binary in my SConstruct file.

    Read the article

  • unbuffered I/O in Linux

    - by stuck
    I'm writing lots and lots of data that will not be read again for weeks - as my program runs the amount of free memory on the machine (displayed with 'free' or 'top') drops very quickly, the amount of memory my app uses does not increase - neither does the amount of memory used by other processes. This leads me to believe the memory is being consumed by the filesystems cache - since I do not intend to read this data for a long time I'm hoping to bypass the systems buffers, such that my data is written directly to disk. I dont have dreams of improving perf or being a super ninja, my hope is to give a hint to the filesystem that I'm not going to be coming back for this memory any time soon, so dont spend time optimizing for those cases. On Windows I've faced similar problems and fixed the problem using FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH - the machines memory was not consumed by my app and the machine was more usable in general. I'm hoping to duplicate the improvements I've seen but on Linux. On Windows there is the restriction of writing in sector sized pieces, I'm happy with this restriction for the amount of gain I've measured. is there a similar way to do this in Linux?

    Read the article

  • Externally disabling signals for a Linux program.

    - by Harry
    Hello, On Linux, is it possible to somehow disable signaling for programs externally... that is, without modifying their source code? Context: I'm calling a C (and also a Java) program from within a bash script on Linux. I don't want any interruptions for my bash script, and for the other programs that the script launches (as foreground processes). While I can use a... trap '' INT ... in my bash script to disable the Ctrl C signal, this works only when the program control happens to be in the bash code. That is, if I press Ctrl C while the C program is running, the C program gets interrupted and it exits! This C program is doing some critical operation because of which I don't want it be interrupted. I don't have access to the source code of this C program, so signal handling inside the C program is out of question. #!/bin/bash trap 'echo You pressed Ctrl C' INT # A C program to emulate a real-world, long-running program, # which I don't want to be interrupted, and for which I # don't have the source code! # # File: y.c # To build: gcc -o y y.c # # #include <stdio.h> # int main(int argc, char *argv[]) { # printf("Performing a critical operation...\n"); # for(;;); // Do nothing forever. # printf("Performing a critical operation... done.\n"); # } ./y Regards, /HS

    Read the article

  • How do I enable SQLite on Linux/Apache/PHP?

    - by Edward Tanguay
    To enable SQLite on my Windows/Apache/PHP setup, I uncomment the following lines in the php.ini file and restart Apache: extension=php_pdo.dll extension=php_pdo_sqlite.dll Now I have a VPS with Suse Linux 10.3 and Apache/PHP was set automatically. Looking through the php.ini file to make the above changes, I see that things are a little different on Linux: there is no list of extensions to uncomment I found "extension_dir = /usr/lib/php5/extensions" but in this directory find only: pdo.so pdo_mysql.so How can I enable SQLite in this Linux environment?

    Read the article

  • How to run a Turnkey Linux virtual machine on XenServer?

    - by Jader Dias
    Turnkey Linux distributes Linux virtual machines in a Xen compatible format. I have a XenServer instance running and I would like to run a recently downloaded Turnkey Linux virtual machine on it. But I have never used XenServer before. Can you point me a tutorial specific for this case, since the manual doens't seem to cover it very well?

    Read the article

  • Why are Linux-based operating systems considered safer than Windows?

    - by echoblaze
    I hear that Linux-based systems are better for security. Apparently they don't have viruses and do not need antivirus software. Even my university claims this - they refuse to have Windows on their servers, which is a real shame because we wanted to use the .NET framework to create some websites. The only reason I can see Linux being safer is because it's open-source, so bugs theoretically would get caught and fixed sooner. I know a bit about how operating systems work, but haven't really delved into how Linux and Windows implement their OS. Can someone explain the difference that makes Linux-based systems more secure?

    Read the article

< Previous Page | 104 105 106 107 108 109 110 111 112 113 114 115  | Next Page >