Messages in this thread | | | Date | Mon, 06 Aug 2007 13:06:47 +0200 | From | dragoran <> | Subject | Re: allow non root users to set io priority "idle" ? |
| |
Andi Kleen wrote: >> couldn't this be fixed by bumping idle tasks to middle while they hold a >> > > Usually to high. > > But it's all complicated and hasn't been done consistently > (there are real time mutexes in the -rt kernel for example, > but there are lots of other locks and they have higher overhead too) > and it's unclear we really want to do all this complexity anyways. > > Also as I said the problem could then still happen in user space > which then would all need to be fixed to handle PI too. > > In some cases the relationship is also not as simple as a single > lock. And for IO handling it would be likely quite hard. > > I personally always found idle priorities quite dubious because > even if they worked reliable for the CPU they will clear your cache/ > load your memory controller and impact all other programs because > of this. And for the disk they will cause additional seeks which are > also very costly. > > ok, thx so that means that the best that can be done for now is to run beagle as best effort with prio 7 (like its done now).
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |