Re: [PARPORT] Re: Something I do not understand in the parport code

Philip Blundell (
Sun, 19 Sep 1999 20:41:06 +0100

>> (BH_IMMEDIATELY) for a function is called as soon as possible,
>> which will carry out the work. And that function may consume ap
>> to 0.15 s before returning (as extreme case). Will that be tolerable?
>I don't know. Would some kernel hacker like to comment? It isn't very
>_nice_, but I think it's tolerable. Basically, no-one else's
>non-immediate bottom halves will get run, so it's probably bad news.

Up to 150ms in a bottom half? I think that will have an unacceptable impact
on things like networking and the serial driver.

If it's taking that long it needs to either be broken into little pieces, or
be organised as a kernel thread that gets woken rather than a bottom half.


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This archive was generated by hypermail 2.0b3 on Sun 19 Sep 1999 - 15:44:54 EDT