Use of double pointer in linux kernel Hash list implementation

Posted by bala1486 on Stack Overflow See other posts from Stack Overflow or by bala1486
Published on 2010-06-17T02:51:21Z Indexed on 2010/06/17 3:13 UTC
Read the original article Hit count: 508

Filed under:

linux

|

linux-kernel

Hi, I am trying to understand Linux Kernel implementation of linked list and hash table. A link to the implementation is here. I understood the linked list implementation. But i am little confused of why double pointers is being used in hlist (**pprev). Link for hlist is here. I understand that hlist is used in implementation of hash table since head of the list requires only one pointer and it saves space. Why cant it be done using single pointer (just *prev like the linked list)? Please help me.

© Stack Overflow or respective owner

Related posts about linux

apt-get install and update fail

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I've got a problem with apt-get update and apt-get install ... commands . every time update or installing fails and errors are : Get:1 http://dl.google.com stable Release.gpg [198B] Ign http://dl.google.com/linux/chrome/deb/ stable/main Translation-en_US Get:2 http://dl… >>> More
kernel module compiling error

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
sh@ubuntu:/home/ccpp/helloworld$ make gcc-4.6 -O2 -DMODULE -D_KERNEL_ -W -Wall -Wstrict-prototypes -Wmissing-prototypes -isystem /lib/modules/`uname -r`/build/include -c -o hello-1.o hello-1.c hello-1.c:4:0: warning: "MODULE" redefined [enabled by default] <command-line>:0:0: note: this is… >>> More
Build-Essentials installation failing

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I am having trouble accessing the several critical header files that show to be a part of the build process. The "Ubuntu Software Center" shows "Build Essentials" as installed: Next I did the following two commands, which did not improve the problem: ~$ sudo apt-get install build-essential [sudo]… >>> More
Updating Debian kernel

as seen on Super User - Search for 'Super User'
I'm trying to update my Debian machine to 2.6.32-46 (which is the new stable). However, after doing apt-get update my apt-cache search linux-image shows me: linux-headers-2.6.32-5-486 - Header files for Linux 2.6.32-5-486 linux-headers-2.6.32-5-686-bigmem - Header files for Linux 2.6.32-5-686-bigmem linux-headers-2… >>> More
Serial connection over a single USB cable (Windows to linux, or linux to linux)

as seen on Server Fault - Search for 'Server Fault'
I'm helping out with a project for an embedded device that only has USB and no serial. This device is running Linux. These days, when we need to connect to a serial port on a device we typically use a USB to serial adapter (on something like a phone system or a load balancing device, etc). I would… >>> More

Related posts about linux-kernel

Out of disk space - /boot at 100%

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
My /boot is at 100%. When I run aptitude search ~ilinux-image I'm getting loads of unused images. When I try to delete one of them (after checking which one is currently in use by doing uname -r), e.g apt-get autoremove linux-image-3.2.0-44-generic I get: Reading package lists... Done Building dependency… >>> More
Linux Kernel Threads - scheduler

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi People, Is Linux Kernel scheduler a part of init process? My understanding is that it is part of Kernel threads managed internally not visible to user by either top or ps. Please correct my understanding. Is it possible to view standard kernel threads through any kernel debugger to see how standard… >>> More
Linux kernel scheduling

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I wish to know how Old Linux scheduling algorithm SJF (shortest job first) calculates the process runtime ? >>> More
The newbie's guide to hacking the Linux kernel

as seen on Internet.com - Search for 'Internet.com'
<b>TuxRadar: </b>"We asked prolific kernel hacker (and Linux Format reader!) Greg Kroah-Hartman to tell us what it takes for newbies to patch the Linux kernel - here's what he had to say." >>> More
Google open source guru says Android code will be in Linux kernel in time

as seen on Internet.com - Search for 'Internet.com'
<b>ZDNet:</b> "Google’s Android code will assume its rightful place in the Linux kernel — in good time, the company’s top open source guru says." >>> More