[ntp:hackers] [Gpsd-dev] Single-writer/many-reader consistency: Test program written

todd glassey tglassey at earthlink.net
Wed Mar 30 16:41:36 UTC 2011


On 3/28/2011 11:23 PM, Terje Mathisen wrote:
> todd glassey wrote:
>> On 3/27/2011 1:17 PM, Terje Mathisen wrote:
>>> As I promised I've written a test program, with one writer and 3
>>> readers (I have 4 cores so all run at all times, I force them to be on
>>> separate cores).
>> What happens with Hex or dual cpu machines? Does the performance scale
>> as well or is it tied to a single-substrate?
>
> The maximum update rate will probably be _slightly_ lower on a 
> multi-chip system, but not by too much.
>
> Anyway, since it is currently running about 5 orders of magnitude 
> faster (13 MHz) than what's needed for a 100 Hz GPS, I really don't 
> worry about it.

My concern is for a shared memory model across a cloud or new C4 type 
infrastructure (this is a new array type model with an incredibly fast 
bus). Also remember I use NTP as a source of evidence and so my overhead 
models are about 2000 times what normal NTP uses today use.
>
> Terje
>
>



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