On Mon, Dec 18, 2006 at 03:37:36PM +1100, Paul Mackerras wrote: > Mohan Kumar M writes: > > > To overcome this problem, I have created the patch, which > > checks for the condition if the machine is ppc970 based and maxcpus > > kernel parameter is specified. If the condition is met, the default > > distribution server is assigned to be current boot cpu instead of > > assigning from the gserver#s property. > > It feels hacky to be basing this sort of thing on the PVR. I would > like to understand the real problem better. Is it that we are > sometimes setting default_distrib_server to point to a CPU which is > not running? If so, why and how?
At the time of kexec/kdump shutdown sequence all secondary processors are removed from the Global Interrupt Queue by calling the corresponding rtas-set-indicator call. So even though default_distrib_server is 0xff PIC should distribute the interrupts only to the processors available in GIQ (please correct me if I am wrong), but its not happening in our JS20 box. Our JS20 firmware version is FW04310120 dated 07/26/04. > Is this something that is specific > to the firmware on IBM 970-based blade systems? Is there in fact a > firmware bug that this works around? Looks like a firmware bug, since I am not able to reproduce this problem on a JS21 box with the firmware version MB240_470 dated 03/23/2006. I am planning to upgrade JS20 with latest firmware and test with maxcpus=1 > Why don't we see it on non-970 > based systems? I have seen secondary thread related interrupt distribution problems on POWER5 boxes and I fixed it sometime back. Since POWER4 does not have SMT there is no interrupt distribution problem. > > Paul. _______________________________________________ fastboot mailing list [email protected] https://lists.osdl.org/mailman/listinfo/fastboot
