Virtual memory implementation Mach OS

Hi, this might help you a bit in understanding how Virtual memory(VM) is implemented in FreeBSD and Mach OS
http://www.geocities.com/no_escape03/mach-vm.pdf

njoy!!!
vaibhav

FreeBSD Network Buffer Allocation

You may find some important information on how Network buffer and its allocation works in FreeBSD in the following pdf file

http://www.bsdcan.org/2004/papers/NetworkBufferAllocation.pdf

njoy!!
Vaibhav

KTR log support implementation in FreeBSD

How can you monitor/log changes you make inside the FreeBSD Kernel?

The KTR support is provided by FreeBSD for tracing the logs that come from the kernel during
its execution.
The following lines must be added to the /usr/src/sys/i386/conf/MYKERNEL file to support
the KTR logs.
options KTR
options KTR_COMPILE=(KTR_MYLOG|KTR_PROC)
options KTR_CPUMASK=0xff
options KTR_ENTRIES=8192
options KTR_MASK=(KTR_MYLOG|KTR_PROC)
To see the logs following command can be used after logging on to the system or any
time during the user processes are run.
sysctl debug.ktr.cpumask=0
ktrdump –o > mylog.log
The file can be viewed using vi mylog.log


use
#man ktr for more information..

vaibhav

How are priority levels handled in FreeBSD for x86?

Question : What FreeBSD 5.2.1 does to handle priority level for x86?
Solution :
(A) Does FreeBSD 5.2.1 still use the spl() macros?

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FreeBSD- compile & install kernel

I am writing here after a very long time ..yeah coz of course work I hardly get time... When the sem started I had no clue what i will be studyin in my OS course but we were made to study FreeBSD deisgn & arch... I now i must say : "I am lovin it". I didn't know what a kernel was & how it worked until I saw the kernel code...
I will be posting a series of imp info on freeBSD and all I know.. I might be wrong at times coz m still studyin it...

The first step one must know is how to compile and install the kernel on freeBSD..
1.
#make -DNOCLEAN buildkernel KERNCONF=MYKERNEL
the -DNOCLEAN allows you to avoid the complete compilation of kernel and compiles only those files that have been modifies. i.e. helps you in avoiding clean compilation
2.
#make installkernel KERNCONF=MYKERNEL
this installs the kernel..
3.
#reboot

the system makes a copy of your old kernel /clean kernel in boot/kernel.old/kernel

Now when you reboot, just let the system use the new copy of your kernel

If you wish to rollback to the old configuration u may choose option "6" from the menu that comes during the booting process .... For this just press "6" .
When u get OK prompts type

OK unload kernel
OK boot boot/kernel.old/kernel

& u r back to the old copy of kernel...yeah the code changes you made will still be there & u need to remember what all changes to did....

my suggestion : When you make change & reboot.. come back to the old copy again to make changes so that the clean copy of kernel remains there...if u make changes to the modified copy & install the changes.. you will loose the clean kernel as u will have a dirty copy of kernel in kernel.old.

there is a lot more to come...
thanx to Dr chapin...

njoy!!!!
Vaibhav ..
Life is all about innovation & quality .....