Kernel_Protector (kernelprotector@yahoo.com) on 5/9/06 wrote:
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>What Tanenbaum says is perfectly correct.

According to you.

>According to my view, since its a kernel, its design should be planned good.
>variable codes(codes which interact with hardware, daily new hardwares appears)
>Vs fixed codes(or not frequently changing codes and 100% >reliable codes and does not deal with hardware)
>only fixed codes should be running in kernel space with full priviledges and variable
>codes should be running in user space.


No amount of planning can substitute for seeing what is going on. If you try to freeze software in stone and never change it over the course of 10 years, you're going to be very very sorry.

>if IPC, Memory management those which has a complete programming which wont have
>bugs(since the codes for these may be small and which wont have any frequent code
>change) only runs in the kernel and everything else(remaining drivers) which might
>have code change even daily runs in the user-level, will result in a good secured and reliable OS.

Has it occurred to you that these functions might need to change over time?

>regarding performance,
>i like to say this...
>i had a program which took 15 minutes to complete with a pentium II processor.the
>same program took 7 mintues to complete with a pentium III processor. and it took
>only 2 or 3 minutes in a pentium IV processor.

Do you write code which can run efficiently (> 90% speed up) on N threads, for arbitrary N? If not, I wouldn't count on that any more.

Besides, just because hardware gets faster isn't an excuse to write bad software. That's like saying that we don't need seat belts in cars since people tend to be healthier over time as nutrition and our understanding of the body improves.

>the performance will be increased by the hardware automatically as time goes on.BUT
>will a kernel safety like microkernel be given by any >hardware automatically ???

Is a ukernel really that much safer than existing operating systems? It seems to me that some systems like VMS, zOS and NSK all have up times as high as a couple of decades. Doesn't seem like safety's really a problem...

[blather snipped]

DK