>Their tlb shootdown is not only synchronous, but it only shoots one page at a time, synchronously. QNX6.6 introduced this too (as a fix for a race condition t

>Their tlb shootdown is not only synchronous, but it only shoots one page at a time, synchronously. QNX6.6 introduced this too (as a fix for a race condition that existed in QNX6.5 and lower) and it was a huge pain to get actual realtime inbetween the TLB flush storms. Like, this is a make-or-break issue right there. TLB flushes can easily eat 10% of all CPU cores if you start and end a process every second.