May 2013 - kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

what's best way for playing with kernel configurations and source code
by Alshamlan, Mohammad May 27, 2013

May 27, 2013

Hi everybody, How you can reconfigure and also modify your source code without affected your system? Please, if you want to suggest a virtual machine is the best option, then could you tell me why? Thanks in advance. -- Best Regards, Mohammad Alshamlan <http://www.linkedin.com/in/maalshamlan/> ARCS: Advanced Real-time and Computing Systems Lab<http://arcs-lab.eng.fiu.edu/> Department of Electrical and Computer Engineering FIU College of Engineering and Computing 10555 West Flagler St. EC 3900 Miami, FL 33174

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hi Why is "can't find a register in class ‘AREG’ while reloading ‘asm’" ?
by lx May 27, 2013

May 27, 2013

hi all: The codes is: static int match(int len,const char * name,struct dir_entry * de) { register int same __asm__("ax"); if (!de || !de->inode || len > NAME_LEN) return 0; if (len < NAME_LEN && de->name[len]) return 0; *__asm__ ("cld\n\t"* "fs ; repe ; cmpsb\n\t" "setz %%al" :"=a" (same) :"0" (0),"S" ((long) name),"D" ((long) de->name),"c" (len) :"cx","di","si"); return same; } When I make it, the error messages is: *namei.c:35: error: can't find a register in class ‘AREG’ while reloading ‘asm’* * * *This is why? * *Thank you*

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File system implementation
by Dibyayan Chakraborty May 27, 2013

May 27, 2013

Hi, I want to implement a file system and integrate with my system. Now first i have to implement the code for disk-formatting(like populating the super_block , root inode etc). I want to see the source code for the ext3 file system for this purpose. Please tell me which file in the kernel source contains the implementation.

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★ Kernelnewbies, Gabriel Duarte te mandou uma mensagem
by Badoo May 26, 2013

May 26, 2013

Gabriel Duarte te mandou uma mensagem Só você pode ver o conteúdo desta mensagem e quem a enviou. Você pode deletar a qualquer momento. Para responder basta clicar no link: http://us1.badoo.com/01241659707/in/Oi7OUnQRcws/?lang_id=61&g=57&m=63&mid=5… Se os links desta mensagem não funcionaram, copie e cole-os na barra de endereços de seu navegador. E-mail enviado como parte do sistema de mensagens do Gabriel Duarte. Se recebeu este e-mail por engano, por favor, simplesmente ignore-o. Em breve a mensagem será removida do sistema. Divirta-se! A Equipe Badoo E-mail enviado por Badoo Trading Limited. http://us1.badoo.com/impersonation.phtml?lang_id=61&email=kernelnewbies%40k… Badoo Trading Limited é uma sociedade limitada registada na Inglaterra e País de Gales sob o CRN 7540255 e firma registrada em 131 - 151 Great Titchfield Street, Londres, W1W 5BB.

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building a kernel from a mounted partition
by Andy Johnson May 25, 2013

May 25, 2013

Hello, I have a dual boot machine, Ubuntu/Fedora. I have a kernel tree on the fedora partition. Now, I had build a kernel on the Fedora partition successfully. I did **not** change anything in the tree, and then When I boot into Ubuntu and mount the fedora partition, and go there and run "make" , it builds ** all ** the tree again ! any I idea why ? And after the build on Ubuntu is over successfully, if I boot into Fedora again and run make, it **again** builds all the tree. Is there a way to avoid this ? rgs Andy

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File System : Block Groups
by Dibyayan Chakraborty May 25, 2013

May 25, 2013

Hi, I have a query regarding the purpose of dividing the entire partition into block groups(as done by ext2 , ext3 ). The main purpose is to replicate the super_block and other important information so that it can be recovered in case of data corruption. Other purpose is to enable efficient storage in order to minimize defragmentation and head seek time. My questions are : Are there any other purpose of this ? How it is possible to detect that there is some corruption in the main super_block information ? Is some kind of check sum is used ? What is the standard way of doing it ? -- With Regards Dibyayan Chakraborty

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Kernel .config file overwritten
by Lakshmipathi.G May 25, 2013

May 25, 2013

Hello - I wanted to compile my kernel from sources. I needed to add one line in .config file, because that option is not possible to change by 'make menuconfig'. But then when I start compilation, these lines are shown at startup: Code: scripts/kconfig/conf --silentoldconfig Kconfig # # configuration written to .config # and my .config is saved as .config.old file and new .config is created. How can I use my manually modified .config file? src: http://ubuntuforums.org/showthread.php?t=2087810 === I'm facing the same problem - anyone here know the solution ? -- ---- Cheers, Lakshmipathi.G FOSS Programmer. www.giis.co.in

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which kernel config creates /dev/usb ?
by Kevin Wilson May 25, 2013

May 25, 2013

Hello, I have configured a kernel, built it and rebooted It is 3.9.0 kernel. There is no /dev/usb after boot (there is of course /dev) Any idea which kernel config creates /dev/usb ? rgs, Kevin

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File System
by Dibyayan Chakraborty May 25, 2013

May 25, 2013

Hi, I want to implement a file system and integrate with my system. Now first i have to implement the code for disk-formatting(like populating the super_block , root inode etc). I want to see the source code for the ext3 file system for this purpose. Please tell me which file in the kernel source contains the implementation.

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CPU usage of particular process
by Rahul Bedarkar May 24, 2013

May 24, 2013

Hi, I am trying to write small program to get CPU usage for a particular process. My logic is to read user, nice, system, idle values from /proc/stat. Then read user and system time from /proc/<pid>/stat. Then wait for some time and again read same values. After that I am doing following calculations CPU% = (no_of_processor * (process_cpu_usage2-process_cpu_usage1) * 100 ) / (total_cpu_usage2-total_cpu_usage1) When I compare my output with top, it looks like correct, but sometimes it is more than 100. Is my logic correct here ? Please correct me if I am worng. Regards, Rahul

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