On Thu, 19 Apr 2007, Ingo Molnar wrote: > i disagree that the user 'would expect' this. Some users might. Others > would say: 'my 10-thread rendering engine is more important than a > 1-thread job because it's using 10 threads for a reason'. And the CFS > feedback so far strengthens this point: the default behavior of treating > the thread as a single scheduling (and CPU time accounting) unit works > pretty well on the desktop. > > think about it in another, 'kernel policy' way as well: we'd like to > _encourage_ more parallel user applications. Hurting them by accounting > all threads together sends the exact opposite message.
There are counter argouments too. Like, not every user knows if a certain process is MT or not. I agree though that doing accounting and fairness at a depth lower then USER is messy, and not only for performance. - Davide - 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/