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Author Topic: [Answered] Why run SMP kernel on single-core 32-bit?  (Read 5059 times)

roarde

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[Answered] Why run SMP kernel on single-core 32-bit?
« on: August 19, 2010, 02:42:30 pm »

Is there an advantage to running an SMP kernel on a single core that couldn't be gained by reconfiguring a non-SMP kernel build?

While we're here, why have RAID there if no partition has multiple drives available?
« Last Edit: August 21, 2010, 01:18:36 am by sixforty »
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Robert
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MikeCindi

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Re: Why run SMP kernel on single-core 32-bit?
« Reply #1 on: August 19, 2010, 03:48:36 pm »

Hopefully I'm not speaking out of turn for the devs but the kernel is "vanilla" to include many possible hardware scenarios. You may gain a little bit of boot time and disk space by compiling a kernel specific to your machine. I have done this a few times in the past (5.x series) but didn't find that it improved much for me. It was a good learning experience though. If you need certain hardware supported that is not included in the default then you'll need to compile your own.

To answer your first question nothing is gained and nothing noticeable is lost. The second question is answered in my first paragraph.

Mike
« Last Edit: August 19, 2010, 03:50:50 pm by MikeCindi »
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VL64 7.1b3                                     RLU 486143

nightflier

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Re: Why run SMP kernel on single-core 32-bit?
« Reply #2 on: August 19, 2010, 05:31:55 pm »

I agree with MikeCindi. The kernel is built to work with a wide range of hardware. Multiple processors is only one of the components that may not exist on your system.
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roarde

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Re: [Answered] Why run SMP kernel on single-core 32-bit?
« Reply #3 on: August 21, 2010, 01:28:40 am »

Thanks for the responses, you told me exactly what I wanted to know.

I'm looking at something that may be used across several non-SMP machines, but may also end up on multi-core and/or 64-bit comps occasionally. Truthfully, I was kinda hoping someone could give a reason that using an SMP kernel is almost always better. IMO, it certainly is better to use just one kernel for general distribution, especially in a distro designed for ease of use; but in this case, there's a need to squeeze the last bit out of everything.

Looking really hard at kernel config is now one more thing on my to-do list, I guess.

Thanks again
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Robert
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MikeCindi

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Re: [Answered] Why run SMP kernel on single-core 32-bit?
« Reply #4 on: August 21, 2010, 08:16:10 am »

Unfortunately, VL doesn't have a viable 64-bit offering...yet. While most of us wouldn't notice a performance advantage with 64-bit the advantage of seeing more RAM without a kernel tweak is the "ease of use" that some would benefit from. The kernel tweak is to enable PAE so that it sees more than the standard 4GB of RAM. I have not yet put serious effort into this though but suspect it's not all that difficult.
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mike99

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Re: [Answered] Why run SMP kernel on single-core 32-bit?
« Reply #5 on: September 22, 2010, 09:10:56 am »

Hello,
"Backward compatability" is a good subject here since i have been saying a long while that Linux does not need alot of resources (ram/cpu) in order to run a "modern" looking OS. My understanding is that the kernel is a rolling upgrade, and gets larger over time. So, can i use a newer kernel with an older machine such as P2/K5 CPU if i bump up the memory to 512mb? Or, would it be better to install an older version of Vector that has an older kernel? I know I'm trying to shove a nickel in a dime slot here, but reason is, i have some older desktops that can be given/donated to Mexico and a couple laptops in the p3 600 range w/256mb memory.
Of course i wonder "if" i would be able to get the wireless to work on those older laptops as well, but maybe the newer kernel will help with that if it does not break the rest of the machine.
#2= is there a kernel cutoff point where support for 2CPU(core?) and/or 4CPU "is" supported. And, will a newer 32-bit kernel work on a laptop that says it is a 64-bit laptop?
#3= has to with Spanish but will post it in the Lang. Department if there is one.
*THANX FOR THE INFO.   mike
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