We seem to have occasions where sending an IPI takes significantly longer than 'normal'.  The cause is still being tracked down but in the meantime there are machines where raising IPI_RETRIES does help - it's not just a case of the machine staying locked up longer and then panic-ing anyway.  Several helpful folks on sparc64@ tried a patch that helped figure out what to raise this number to.
We seem to have occasions where sending an IPI takes significantly
longer than 'normal'.  The cause is still being tracked down but
in the meantime there are machines where raising IPI_RETRIES does
help - it's not just a case of the machine staying locked up longer
and then panic-ing anyway.  Several helpful folks on sparc64@ tried
a patch that helped figure out what to raise this number to.

Discussed on:	sparc64@
MFC after:	3 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase