Re: mlock(1)

[Neil Horman <nhorman@redhat.com>]

Neil Horman wrote:
> Jeff Garzik wrote:
> 
>>
>> How feasible is it to create an mlock(1) utility, that would allow 
>> priveleged users to execute a daemon such that none of the memory the 
>> daemon allocates will ever be swapped out?
>>
>> ntp daemon does mlock(2) internally, for example, but IMHO this is 
>> really a policy decision that could be moved out of the app.
>>
>> Unfortunately I am VM-ignorant as always ;-)
>>
>>     Jeff
>>
> 
> I think it would be pretty easy to do.  Since mlock(2) operates on the 
> calling processes vma tree you'd need an interface to the kernel that 
> let you specify a child process and an address range to lock.  Then in 
> the kernel you'd need to translate the pid into task struct and 
> replicate the functionality of sys_mlock without the assumption that 
> current points to the task that you're modifying.  Sounds like something 
> you could do pretty easy with a proc file in fact.
> 
> 
> Neil
> 
>>
>>
>> -

Clarification: didn't mean to say child process there.  Any process 
would be modifiable with this interface I think.
Neil

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