Peter Nguyen petern at
Mon Apr 30 06:31:03 CEST 2007

OK.  Where is this code located? 

I'm currently using L4Ka::Pistachio, API version 0x84.0x5, Kernel ID 4.2 (as
stated when printing out the KIP in open firmware).

Some other questions:

1) Are external interrupts disabled during the polling process as well?
2) Forgive my ignorance, but is L4 multithreaded? I'm asking this because of
the minimal nature of a microkernel (which may not require multithreading
given the minimal code that theoretically is there to execute).

Ben Leslie-2 wrote:
> On Wed Apr 25, 2007 at 18:50:21 -0700, Peter Nguyen wrote:
>>OK, so with that in mind, where does the polling take place?  I might be
>>wrong in saying this, but is there a portion of code that deals directly
>>with the polling of I/O?  The reason i ask this is that i think that the
>>polling of I/O has an affect on the performance monitoring facilities,
>>specifically when a performance counter overflows.  This would, in turn,
>>have an affect on the ability to take samples given that samples might not
>>be taken while waiting for input.
> On our kernel this happens within the kernel itself. There is also a
> non-blocking version which allows you to perform the polling at
> user-level itself. I would suggest you do this which would possibly
> avoid the problems you are seeing.
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