priority controlled multitasking and UNIX OSs
3 Dec 2005 21:35:48 UTC
Topic 190288
(moderation:
as far as I know most UNIXs don't have something like Win32 priority controlled multitasking -- they have priorities controlled by the "nice" tool -- but these priorities don't have any effect which can be detected by humans. So running boinc on UNIXs will slow down the response time of your normal applications.
Isn't this annoying?
priority controlled multitasking and UNIX OSs
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And I thought it was the other way around....
Seriously this is just not true. BOINC runs with the lowest possible
priority (19), any "normal" user process runs at normal (0) priority.
Kernel processes at hight priority (e.g. -5). nice is just a tool
to modify the priority of a process.
So there is no problem running BOINC.
Stil can't stop shaking my head and wondering where you got that from.
A M$ website?
Michael
Team Linux Users Everywhere
RE: >> as far as I know
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> Seriously this is just not true. BOINC runs with the lowest possible
> priority (19), any "normal" user process runs at normal (0) priority.
and does this low priority have any effect which can be determined by humans?
E.g. will boinc be stopped dead if a process with higher prirority needs CPU time?
From my experience with various unixes priorities don't have any effect on UNIX -- processes share the CPU nearly independent of the "nice" setting.
The exception was solaris and "nice +19" -- but they "fixed" this meanwhile.
LINUX is similar.
Try running a CPU intensive task in the foreground and measure how long it takes -- without boinc running.
Then repeat this with boinc running.
On NT it takes the same amount of time -- due to priority class idle set for boinc.
Nt 3.51 offered focus controlled multitasking -- this was the best.
Also see
http://www.foelsche.com/PriorityHook/index.htm
Michael is right, you are
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Michael is right, you are wrong about Unix and 'nice'...
Perhaps if you are on a low utilization box, 'nice' might not matter too much...
If the Unix box is getting hammered, you will see a diff in the process utilization...
RE: Michael is right, you
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Been dealing with unix since
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Been dealing with unix since '87... professionally.
Unix is not a single user system. If you expect one process to have full CPU control, that just isn't going to happen.
> Unix is not a single user
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> Unix is not a single user system.
> If you expect one process to have full CPU control,
> that just isn't going to happen.
It actually was happening on SOLARIS until some time ago.
There nice +19 meant, that this process would not get the CPU if other processes with higher priority needed the CPU.
I can imagine the uselfullness of such a priority scheme.
I can see the usefulness right now
-- by running boinc on my system without slowing me down.
That you cannot see the usefulness shows that you are religions
-- unable to see the usefulness of something
because it does not match you religion.
Ok, I will not debate this
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Ok, I will not debate this further.
Keep on crunching, people way smarter than us need the help.
By the way -- that no such
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By the way -- that no such priority scheme exists UNIXs prevents me from running boinc on all the machines in my office
-- people would not put up with such a process taking CPU time
when they need the CPU.
Peter, I'm going to make
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Peter,
I'm going to make the assumption that you are not deliberately trying to insult the intelligence of the people who have responded to you with your offensive claims of religious zealotism, otherwise I wouldn't bother responding at all. The simple fact of the matter is that all flavours of unix do manage and prioritize tasks, and probably far better than Windows ever did.
I believe that capnrob97 was trying to point out that unix is true multitasking where even the highest priority tasks are going to release spare cpu cycles to lower priority tasks simply because they don't need them. Because of that, one process does not "own" the cpu and all tasks will get a chance of grabbing those otherwise spare cycles.
The fact that you choose not to understand what was being said, and even worse, to pour scorn on it when people responding to you were doing so in a calm and rational manner, seems to indicate that you don't really understand the nature and capabilities of unix. You are entitled to your own opinions but please don't insult the collective intelligences of those who do know a little about unix with claims that only SOLARIS knew how to prioritize tasks. And when you have no better argument to support your case please don't start insulting people.
Cheers,
Gary.
RE: Peter, > I believe
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