On Fri, Jun 19, 2009 at 05:52:02PM +0200, Nils Goroll wrote: > I am trying to reduce context switches on a V890 with 16 cores by > delegating one core to interrupt handling (by setting all others to > nointr using psradm).
The best way to do this is to create processor sets, with the set that handles OS tasks containing processors that handle interrupts and the other set containining the nointr processors. If you're really concerned about context switching, you might also benefit from processor binding, which only lets a process run on a particular cpu. Lately, the scheduler guys have made a bunch of improvements that allow processes to be more sticky, though. (Less likely to migrate from one CPU to another, but that is different from a context switch) What version of the OS are you running? > Does the hardware design of this machine imply that (a) particular > core(s) is best suited for this task? Almost any multiprocessor machine that has NUMA characteristics will benefit from having the interrupts placed on the CPU that's closest to the hardware that connects to the bus that the interrupts are coming from. From a discussion long ago, I remember the v890 has some NUMA characteristics, but I don't honestly know if we treat it like a NUMA machine. Jonathan Chew, who's lurking on the list somewhere, might have more details. -j _______________________________________________ perf-discuss mailing list perf-discuss@opensolaris.org
