Why not? We could add a flag bit to task_struct that means "RT
process". So kernel entry points would just need to check
current->is_rt
> then
> call rt scheduler with error indication
>
> the rt scheduler would then mark the current rt task with an error
> condition and let it handle it. We'd bypass the linux scheduler entirely
> and would have to add a RT call
> run_user_mode_process(p);
Why not move the process to a Linux run queue on kernel traps? This
would take the process off the RTL run queue and would cause RTL to
call rtl_schedule() (or equivalent). This would (possibly) cause Linux
to be scheduled and thus normal kernel processing would continue.
> Doesn't sound so bad now. A error would basically loose RT
> functionality: that seems ok.
Dropping RTL priority when you enter kernel mode is fine.
> But it would require a bigger Linux patch.
Indeed.
> I described this idea to Linus and it made him deeply unhappy.
Precisely what made him unhappy? The requirement to patch all kernel
entry and exit points? Or just the concept of dropping RTL priority?
Regards,
Richard....
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