Re: Today Linus redesigns the networking driver interface (was Re: tulip driver in ...)
Richard Gooch (rgooch@atnf.csiro.au)
Wed, 23 Sep 1998 23:21:59 +1000
Andrea Arcangeli writes:
> On Wed, 23 Sep 1998, Richard Gooch wrote:
>
> >BTW: if you're idling, that doesn't mean that BH's are called before
> >the next timer tick. AFAIK do_bottom_half() is only called on return
> >from syscall/interrupt and when rescheduling.
> >Waiting for the next timer tick would be horrible for latency,
> >though.
>
> If you queue the handler in the timer_bh OK, you are sure that the
> bh will be marked (in the worst case after 1/HZ sec). All other bh
> has not timeout so if you don' t mark it and there are not other
> code that mark it _incidentally_ the bh handler will never run. This
> is what I understand from the code.
My point is that 1/HZ is a *long* time. 10 ms for packet processing is
awful.
Regards,
Richard....
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