* Linus Torvalds <[EMAIL PROTECTED]> wrote: > > It has been said that "perfection is the enemy of good". The two > > interactive tasks receiving 40% cpu while two niced background jobs > > receive 60% may well be perfect, but it's damn sure not good. > > Well, the real problem is really "server that works on behalf of > somebody else".
i think Mike's testcase was even simpler than that: two plain CPU hogs on nice +5 stole much more CPU time with Con's new interactivity code than they did with the current interactivity code. I'd agree with Mike that a phenomenon like that needs to be fixed. /less/ interactivity we can do easily in the current scheduler: just remove various bits here and there. The RSDL promise is that it gives us /more/ interactivity (with 'interactivity designed in', etc.), which in Mike's testcase does not seem to be the case. > And the problem is that a lot of clients actually end up doing *more* > in the X server than they do themselves directly. yeah. It's a hard case because X is not always a _clear_ interactive task - still the current interactivity code handles it quite well. but Mike's scenario wasnt even that complex. It wasnt even a hard case of X being starved by _other_ interactive tasks running on the same nice level. Mike's test-scenario was about two plain nice +5 CPU hogs starving nice +0 interactive tasks more than the current scheduler does, and this is really not an area where we want to see any regression. Con, could you work on this area a bit more? Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/