Kernelnewbies Digest, Vol 19, Issue 43
flat view
From: zhaoqiao <hidden>
Date: 2012-06-22 01:29:02
2012/6/22 [off-list ref]
Send Kernelnewbies mailing list submissions to kernelnewbies at kernelnewbies.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies or, via email, send a message with subject or body 'help' to kernelnewbies-request at kernelnewbies.org You can reach the person managing the list at kernelnewbies-owner at kernelnewbies.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Kernelnewbies digest..." Today's Topics: 1. Re: download the source code of some commands (Greg Freemyer) 2. could some current.h files be simplified? (Robert P. J. Day) 3. Re: download the source code of some commands (Wang Lei) 4. Re: download the source code of some commands (??) 5. Re: Kernel Memory (michi1 at michaelblizek.twilightparadox.com) ---------------------------------------------------------------------- Message: 1 Date: Thu, 21 Jun 2012 10:42:12 -0400 From: Greg Freemyer <redacted> Subject: Re: download the source code of some commands To: ?? <redacted> Cc: kernelnewbies <redacted> Message-ID: <CAGpXXZLM7s_=2xWcEDFtSrj_0-EjgP7aP7XNu1XEmZMEhXT53w@mail.gmail.comquoted
Content-Type: text/plain; charset=UTF-8 On Thu, Jun 21, 2012 at 8:48 AM, ?? [off-list ref] wrote:quoted
? Hi all: ? ? ?? I want to see some source code of some commands,for example,halt,reboot,uptime,and so on. but i don't kown where to download??? can you give me some advice? Thanks in advance!You need to figure out how your distro of choice lets you query the filelist for packages. I use openSUSE primarily and it has the Yast tool that lets you do that in the software management section. uptime => coreutils reboot => aaa_base halt => aaa_base Once you know the package your distro uses you can download the corresponding source package for it. You will have better luck learning the process you need to know by asking on a distro specific mailing list. Greg hi,
you can use the download tool to get the sources code. eg: apt-get source ssh (ubuntu) you can get ssh source code. but, not all !
------------------------------ Message: 2 Date: Thu, 21 Jun 2012 10:54:59 -0400 (EDT) From: "Robert P. J. Day" <redacted> Subject: could some current.h files be simplified? To: Kernel Newbies <redacted> Message-ID: <alpine.DEB.2.02.1206211048240.22454@oneiric> Content-Type: TEXT/PLAIN; charset=US-ASCII it *seems* as if a number of current.h files from various architectures could be simplified. here's <asm-generic/current.h>, which gives any architecture a generic starting point in defining both get_current() and current: #ifndef __ASM_GENERIC_CURRENT_H #define __ASM_GENERIC_CURRENT_H #include <linux/thread_info.h> #define get_current() (current_thread_info()->task) #define current get_current() #endif /* __ASM_GENERIC_CURRENT_H */ and if that's acceptable, any architecture is welcome to simply include it as, for instance, mips does in <asm/current.h>: #include <asm-generic/current.h> but here's the current.h file for parisc: #ifndef _PARISC_CURRENT_H #define _PARISC_CURRENT_H #include <linux/thread_info.h> struct task_struct; static inline struct task_struct * get_current(void) { return current_thread_info()->task; } #define current get_current() #endif /* !(_PARISC_CURRENT_H) */ i'm not sure i see why the generic version wasn't adequate for parisc (apart from the explicit pointer casting). same thing with the cris architecture and, i'm sure, others. is there any reason why some of those current.h files can't just include the generic one? rday -- ======================================================================== Robert P. J. Day Ottawa, Ontario, CANADA http://crashcourse.ca Twitter: http://twitter.com/rpjday LinkedIn: http://ca.linkedin.com/in/rpjday ======================================================================== ------------------------------ Message: 3 Date: Thu, 21 Jun 2012 23:22:49 +0800 From: Wang Lei <redacted> Subject: Re: download the source code of some commands To: ?? <redacted> Cc: kernelnewbies <redacted> Message-ID: [ref] Content-Type: text/plain; charset=utf-8 If you use Debian or other distribution with apt package system. You can use whereis to locate this command. [~]$ whereis halt halt: /sbin/halt /usr/share/man/man5/halt.5.gz /usr/share/man/man8/halt.8.gz Then, use dpkg -S to show which package it's included. This one is: sysvinit. [~]$ dpkg -S /sbin/halt sysvinit: /sbin/halt Now, you can download the source from Debian source, use: [~]$ apt-get source sysvinit Or if you want the original source, use aptitude (or apt-cache) find it's homepage. [~]$ aptitude show sysvinit Package: sysvinit ...... Homepage: http://savannah.nongnu.org/projects/sysvinit At last, get it from there. As for other package systems, I think there should be a way too. Or you can google. On 2012-06-21 20:48:48 +0800, ?? wrote:quoted
Hi all: I want to see some source code of some commands,for example,halt,reboot,uptime,and so on. but i don't kown where to download? can you give me some advice? Thanks in advance! _______________________________________________ Kernelnewbies mailing list Kernelnewbies at kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies-- Regards, Lei ------------------------------ Message: 4 Date: Thu, 21 Jun 2012 23:46:21 +0800 From: ?? <redacted> Subject: Re: download the source code of some commands To: Wang Lei <redacted> Cc: kernelnewbies <redacted> Message-ID: <CAJrRU3XDpS620jOe+Q8W+siuGvR3CzzJOHZg3e+pWSSU5t0Tuw@mail.gmail.comquoted
Content-Type: text/plain; charset="gb2312" 2012/6/21 Wang Lei [off-list ref]quoted
If you use Debian or other distribution with apt package system. You can use whereis to locate this command. [~]$ whereis halt halt: /sbin/halt /usr/share/man/man5/halt.5.gz /usr/share/man/man8/halt.8.gz Then, use dpkg -S to show which package it's included. This one is: sysvinit. [~]$ dpkg -S /sbin/halt sysvinit: /sbin/halt Now, you can download the source from Debian source, use: [~]$ apt-get source sysvinit Or if you want the original source, use aptitude (or apt-cache) find it's homepage. [~]$ aptitude show sysvinit Package: sysvinit ...... Homepage: http://savannah.nongnu.org/projects/sysvinit At last, get it from there. As for other package systems, I think there should be a way too. Or you can google.Thank you very much ! i follow your steps, and download the source code successfully. On 2012-06-21 20:48:48 +0800, ?? wrote:quoted
Hi all: I want to see some source code of some commands,for example,halt,reboot,uptime,and so on. but i don't kown where to download? can you give me some advice? Thanks in advance!quoted
quoted
_______________________________________________ Kernelnewbies mailing list Kernelnewbies at kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies-- Regards, Lei-------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20120621/6e586022/attachment-0001.html ------------------------------ Message: 5 Date: Thu, 21 Jun 2012 17:48:25 +0200 From: michi1 at michaelblizek.twilightparadox.com Subject: Re: Kernel Memory To: Vijay Chauhan <redacted> Cc: kernelnewbies at kernelnewbies.org Message-ID: <20120621154824.GA2280@grml> Content-Type: text/plain; charset=us-ascii Hi! On 17:57 Thu 21 Jun , Vijay Chauhan wrote:quoted
Hello, I am newbie. It has been said "kernel memory is not pageable" What does it mean? There is no concept of kernel virtual address? Any simple explanation will help me to udnerstand.The right term is actually "kernel memory is not swappable". Swapping means writing inactive memory to disk and then using it for something else. Kernel memory not being swappable is a design decicion made in the early linux days. Operating systems which swap kernel memory need to isolate everything which should not be swappd out (e.g. things needed for swap-in, realtime stuff, security sensitive data, ...). This is quite a bit of work. I also guess it is pretty pointless nowadays. Installed memory and is getting so huge that virtual memory developers have a hard time trying to keep cpu-usage overhead for swapping user space memory low.quoted
There is no concept of kernel virtual address?Kernel memory uses virtual addresses as well. However, these the entire system memory is continuously mapped somewhere in the virtual address space. The drawback is that fragmentation turns allocation of large continuous memory regions into a game of luck. There is also an virtual address area (vmalloc) which is used to dynamically map multiple scattered pages to a continuous region. But this is rather slow and rarely used. You might want to take a look at: http://lwn.net/Kernel/LDD3/ -Michi -- programing a layer 3+4 network protocol for mesh networks see http://michaelblizek.twilightparadox.com ------------------------------ _______________________________________________ Kernelnewbies mailing list Kernelnewbies at kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies End of Kernelnewbies Digest, Vol 19, Issue 43 *********************************************
-------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20120622/de0985e7/attachment-0001.html