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Re: How to kill slave kernel securely?

• To: mathgroup at smc.vnet.net
• Subject: [mg117164] Re: How to kill slave kernel securely?
• From: Oliver Ruebenkoenig <ruebenko at wolfram.com>
• Date: Thu, 10 Mar 2011 06:42:26 -0500 (EST)
• References: <201103091200.HAA14063@smc.vnet.net> <Pine.LNX.4.63.1103090610360.22963@wopr.wolfram.com>

On Thu, 10 Mar 2011, Alexey Popkov wrote:

>
>
> From: "Oliver Ruebenkoenig" <ruebenko at wolfram.com>
> To: "Alexey Popkov" <lehin.p at gmail.com>
> Cc: "comp.soft-sys.math.mathematica" <mathgroup at smc.vnet.net>
> Sent: Thursday, March 10, 2011 12:39 PM
> Subject: Re: [mg117082] How to kill slave kernel securely?
>
>
>> On Thu, 10 Mar 2011, Alexey Popkov wrote:
>>
>>> Instead of MemoryConstrained I would prefer to have
> 'FreeMemoryConstrained'
>>> function to protect from swapping securely...
>>>
>>
>> What is holding you from setting that MemoryConstraint to the amount of
>> physical memory you have?
>
> There are two problems:
>
> 1) I cannot know how much memory I should allow MathKernel to allocate
> because other applications can allocate memory too. If I simply set
> MemoryConstrained to the amount of physical memory or even to the half of
> physical memory the system still can go into swapping. From the other side I
> do wish to allow MathKernel to use almost all available free physical memory
> with except for about 200 MB which must be always available for other
> applications.

I am not sure I understand that. How would you that know with 
FreeMemoryConstrained.

If you do not want your system to go into swap, have you tried switching 
it off in the first place?

Assuming you are on Linux you could use ulimit to set memory constraints. 
This then would allow other processes to access the rest of the memory. I 
have no idea how and if this works, say, on windows.

>
> 2) My bitter experience with MemoryConstrained clearly shows that it is not
> a reliable function. It practical cases when I heavily use such functions as
> NDSolve, NIntegrate etc. it often allows MathKernel to take for example
> 500-900 MB more that I have set. And system goes into swapping...
>

You could forward that to the tech support for us to look at.

Oliver

• References:
  • How to kill slave kernel securely?
    • From: Alexey <lehin.p@gmail.com>