kernel thread as real threads..

Julian Elischer julian at
Mon Jan 23 14:22:50 PST 2006

John Baldwin wrote:

>On Thursday 19 January 2006 21:56, Julian Elischer wrote:
>>some progrsss..
>>as the first few lines show, it's not quite perfect yet but it's most of
>>the way there..
>>(Like proc 1 isn't init)
>One other note, watch out for the AIO daemons.  They have to be kernel procs 
>and not kthreads because they borrow the vmspace of the user process when 
>performing AIO on another process' behalf.
yeah I found that and the patches account for that.

However I would like to suggest that we change the way that aio works..

My suggestion is that when a process does AIO, that we "fork a ksegroup" 
and attach it to the
process, and assign it a (or some) worker thread to do the aio work.  
The userland process would
be oblivious of the extra (kernel) threads in that kseg and they would 
be independently schedulable.
They would however automatically have full access to the correct address 

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