But if your interrupt handler doesn't register/mark a BH, then the
costs of "BH processing" (i.e. (bh_active & bh_mask)) are
trivial. Where is the gain in that extra flag?
> In truth for most of those cases running RTLinux is far simpler, far
> faster and far more reliable since in the RTLinux case you _will_
> hit your irq latency deadlines not "most of the time".
Unfortunately RTLinux is further removed from the "real world" of
Linux. Launching RTLinux processes is quite different (you have to
load a module), and you don't get message queues, semaphores and the
things people expect. I've had just this criticism from someone
considering to use Linux/RTLinux instead of pSOS+.
>From looking at the current Linux capabilities, it looks to me like we
can indeed give hard-RT performance. Sure, it may mean not using
broken 8390 drivers which globally disable interrupts while spending
1.6 ms reading a packet, but hey, we can live with that ;-)
Being able to do all this with normal Linux without having to resort
to RTLinux is a goal worthy of pursuit.
Regards,
Richard....
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