Messages in this thread | | | Date | Fri, 10 Oct 2003 08:21:20 -0700 | From | William Lee Irwin III <> | Subject | Re: 2.7 thoughts |
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William Lee Irwin III wrote: >> You need at least enough warning to get out of critical sections (e.g. >> holding a spinlock) and dump registers out to memory. i.e. as long as it >> takes to schedule out whatever's currently running on the thing. >> ... and unless you want to start enforcing realtime bounds, the answer >> to "how long do you have to give the kernel to do it?" is "forever". >> In practice, it won't take forever, but no finite time is enforcible.
On Fri, Oct 10, 2003 at 04:12:31PM +0100, Jamie Lokier wrote: > You can create a very peculiar scheduling state to make even > spinlocked sections multi-task, so the CPU can be released in a finite > time and quickly - about as quickly as taking an NMI and broadcasting > the critical IPIs to tell other CPUs to take over. > The peculiar state is restored to normal as soon as the number > of concurrent critical sections no longer exceeds the number of real CPUs.
DOH. Okay, that would do it.
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