Messages in this thread |  | | Date | Thu, 5 Oct 2000 11:20:49 +0200 | From | Pavel Machek <> | Subject | Re: Weightless process class |
| |
Hi!
> A process can't grab a kernel lock and then switch > back to user mode, can it? (if it could, I can > imagine some nasty DoS attacks...) > > Problem is, when we decide to schedule in a process > or not, we know the process was last stuck in > schedule() ... in kernel mode ;( > > I'd love to be proven wrong though ... this would be > some extremely useful functionality ;)
There was solution to it: bumping priority to normal when process is in kernel. Hard part was how to do it with 0 impact on normal kernel operation, and even that was solved (as you are testing for ptrace, anyway, you can make it test for extremely-low-prio in same assembly instruction). Pavel -- The best software in life is free (not shareware)! Pavel GCM d? s-: !g p?:+ au- a--@ w+ v- C++@ UL+++ L++ N++ E++ W--- M- Y- R+ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
|  |