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  Linus Torvalds apologizes for Linux 4.8 kernel bug


On Oct 2, Linus Torvalds proudly announced the release of Linux 4.8. But just days after the release, a bug was found in the kernel and Linus came out and apologized for this bug. I'm really sorry I applied that last series from Andrew just before doing the 4.8 release, because they cause problems, and now it is in 4.8 (and that buggy crap is marked for stable too). In particular, I just got this kernel BUG at ./include/linux/swap.h:276 and the end result was a dea...

   LINUX,LINUX KERNEL,NEWS,LINUS TORVALDS,BUG_ON     2016-10-07 03:46:17


  New Linux kernel fixes power-saving issues


Greg Kroah-Hartman has released long-term kernel 3.0.20 and stable kernel 3.2.5. Both contain just a single bug fix that allows PCIe power-saving technology ASPM (Active State Power Management) to be used on systems with a BIOS that activates ASPM on some components, but states in the FADT (Fixed ACPI Description Table) consulted by Linux that ASPM is not supported. According to Matthew Garrett, who developed the patch, the change can reduce the power consumption of a Thinkpad X220 by 5&nbs...

   Linux kernel,Power saving,Fix     2012-02-08 10:10:36


  Microsoft is the 17th largest contributor to Linux


The Linux Foundation has released 2012 Linux White Paper which analyzes developers and contributors of the Linux kernel from 2.6.36 to 3.2.The top ten contributors are: Red Hat, Intel, Novell, IBM, Texas Instruments, Broadcom, Nokia, Samsung, Oracle, and Google. The software giant Microsoft's contribution ranked at 17, while the company's CEO Steve Ballmer has claimed previously that Linux is a cancer. Microsoft engineers have contributed 688 patches, which are mostly related to Hyper-V vir...

   Linux,Microsoft,Contribution     2012-04-05 07:43:19


  About tmpfs


tmpfs is another confusing name in Linux kernel, its implementation is in mm/shmem.c, shmem has no relation to tmpfs at first glance although we know tmpfs is based on memory. We can understand why we use this name by seeing where this is used. In a desktop Linux system, tmpfs is loaded usually: % grep tmpfs /proc/mountsdevtmpfs /dev devtmpfs rw,seclabel,nosuid,relatime,size=1958956k,nr_inodes=489739,mode=755 0 0tmpfs /dev/shm tmpfs rw,seclabel,nosuid,nodev,relatime 0 0tmpfs /run tmpfs rw,seclab...

   tmpfs,Linux,file system     2013-06-14 12:10:56


  Building The Linux Kernel In 60 Seconds


In less than one minute, it's now possible to build the Linux kernel from source on a desktop. Besides finishing up the Phoronix Test Suite 3.6-Arendal release this weekend, on Saturday I began running some new Intel CPU benchmarks. In building the Linux 3.1 kernel for x86_64 in a default configuration (make defconfig), I've now managed to trim down the compile time to less than sixty seconds on a single-socket desktop system. Similar speeds can be achieved out of multi-socket servers and othe...

   Linux kernal,Build,Intel processor,sgort time     2011-12-12 07:45:32


  Shortest command on Linux


Usually when we log in to a Linux system,. we may type some frequently used Linux commands such as pwd,ls, ps etc. All these commands are really simple but powerful with different options. But do you know what is the shortest command on Linux? The answer is w. According to Linux manual, w will show who is logged on and what they are doing on the system. w displays information about the users currently on the machine, and their processes. The header shows, in this order, the current time, how l...

   Linux,w,shortest command     2014-04-30 11:07:38


  How Computers Boot Up


The previous post described motherboards and the memory map in Intel computers to set the scene for the initial phases of boot. Booting is an involved, hacky, multi-stage affair – fun stuff. Here’s an outline of the process: An outline of the boot sequence Things start rolling when you press the power button on the computer (no! do tell!). Once the motherboard is powered up it initializes its own firmware – the chipset and other tidbits – and tries to get the CPU running...

   Computer,Boot-up,Rationale     2012-04-11 13:43:02


  Beginners guide to Linux directory structure


Have you ever looked in your / directory, you’ll see a lot of directories. Here we are presenting beginners guide to linux directory structure explaining what they mean and what are the contents of these directories.Screenshot of contents of root directory: /This is called root partition. All files and directories start with root partition. Write privileges under this directory are avaible with root user only. Not to confuse it with root user’s home directory, know the difference...

   Linux,File system structure,Beginner's guide     2012-04-20 12:19:32


  System programming is still there


System programming is the practice of writing system software. System software lives at a low level, interfacing directly with the kernel and core system libraries. Your shell and your text editor, your compiler and your debugger, your core utilities and system daemons are all system software. But so are the network server, the web server, and the database. These components are entirely system software, primarily if not exclusively interfacing with the kernel and the C library. But nowadays more...

   System programming     2014-02-27 05:46:48


  do {...} while (0) in macros


If you are a C programmer, you must be familiar with macros. They are powerful and can help you ease your work if used correctly. However, if you don't define macros carefully, they may bite you and drive you crazy. In many C programs, you may see a special macro definition which may seem not so straightforward. Here is one example: #define __set_task_state(tsk, state_value) \ do { (tsk)->state = (state_value); } while (0) There are many this kind of macros which uses do{...}while(0)...

   C,macro,C++     2014-01-23 07:16:13