S
Stan Brown
On Wed Jan 19 22:10:18 2000 Phil Covington wrote...
>
>----- Original Message -----
>From: "Stan Brown" <[email protected]>
>
><snip>
>
>> Are you asying we can't get to an _average_ scan time in the 10's of
>> milliseconds with the standard scheduler? Or are you concerned that
>> some scans may be long? If so by about how much?
>>
>> --
>
>Unfortunately I am saying that even with the POSIX soft realtime support in
>the normal linux kernel you are not going to see scan times under 20 ms on
>an unloaded system. With increasing system load the scans will be even
>longer by an unpredictable amount and will jump around all over the place (jitter). <
Hmm, wasn't there a second choice in the realtime flavors that used POSIX calls?
--
Stan Brown [email protected] 843-745-3154
Westvaco
Charleston SC.
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>
>----- Original Message -----
>From: "Stan Brown" <[email protected]>
>
><snip>
>
>> Are you asying we can't get to an _average_ scan time in the 10's of
>> milliseconds with the standard scheduler? Or are you concerned that
>> some scans may be long? If so by about how much?
>>
>> --
>
>Unfortunately I am saying that even with the POSIX soft realtime support in
>the normal linux kernel you are not going to see scan times under 20 ms on
>an unloaded system. With increasing system load the scans will be even
>longer by an unpredictable amount and will jump around all over the place (jitter). <
Hmm, wasn't there a second choice in the realtime flavors that used POSIX calls?
--
Stan Brown [email protected] 843-745-3154
Westvaco
Charleston SC.
_______________________________________________
LinuxPLC mailing list
[email protected]
http://linuxplc.org/mailman/listinfo/linuxplc