Re: Fiasco.OC performance issues
Adam Lackorzynski <[email protected]>
| Newsgroups | gmane.comp.micro-kernel.l4.devel |
|---|---|
| Message-ID | <[email protected]> |
On Thu Jan 17, 2013 at 17:03:36 +0100, Sebastian Sumpf wrote: > I recently upgraded Fiasco.OC to SVN revision 42 and experience some > pretty severe performance degradation compared to revision 40 on the > Pandaboard (SMP). It seems that 'simga0' and the root task stall for 5 > to 10 seconds during boot up. I tracked the issue down to be caused by > the initial mapping operations, especially our root task maps all the > available memory during bootstrap. Within the kernel the > 'Context::xcpu_tlb_flush' is called for each mapping. The function sends > an IPI (to CPU1 which is idle) and then waits for an IPI in order to > signal the end of the operation. The whole operation seems to have > gotten slower compared to revision 40, but I could not find many > differences in the IPI-handling code. Do you have any ideas or > suggestions what could cause the delay (maybe scheduling changes) and > how to fix it? I noticed a similar/same thing but hadn't time to investigate yet. Adam -- Adam [email protected] Lackorzynski http://os.inf.tu-dresden.de/~adam/