4 ms·
Look up the Blackberry Playbook vs iPad comparison they did a while back. Playbook was QNX-based. They were browsing with some games running IIRC. There wasn't
by nickpsecurity 9y ago
Look up the Blackberry Playbook vs iPad comparison they did a while back. Playbook was QNX-based. They were browsing with some games running IIRC. There wasn't any lag on the switches. Being a RTOS, it stayed responsive.
The BeOS demo toward the end is similar where they fire up a load of 3D apps, videos, etc with the system gradually slowing but still handling the load. That was on mid-90's hardware.
EROS was a capability-secure microkernel with persistence for saving or restoring running state of system. One thing they liked doing at demos was unplugging it during file transfers. After it restarted, the system would pick up where it left off.
In security side, there's been a few security and separation kernels to never have a reported breach in the field. They passed 2-5 years of pentesting by evaluators, too, doing many times better than monolithic kernels in defects found. Also easier to mitigate covert channels or do formal verification since they're small enough to analyze to begin with.
- zokula 9y agoOne of those things is not like the others. BeOS did not have a microkernel.
- nickpsecurity 9y agoAll the reporting I've seen on it said it had a microkernel. I've included both the first thing from Google and my UNIX Alternatives List that has an in-depth link on BeOS. https://arstechnica.com/information-technology/2008/02/first-look-haiku-poetically-resurrects-beos/ https://arstechnica.com/information-technology/2008/02/first... https://news.ycombinator.com/item?id=10957020 https://news.ycombinator.com/item?id=10957020 It also had the kind of compile-time slowdowns one expects with a lot of context switches on older CPU's. So, what's your source that there's not a microkernel at the center?
- waddlesplash 9y agoBeOS absolutely did not have a microkernel; all the hardware drivers, filesystem interfaces, and lowest-level network protocols ran in ring 0.
- nickpsecurity 9y agoI appreciate you replying. Since it's you saying it, I'll stop saying it's a microkernel for now. I am curious why people said it so much. Maybe you could help there in even there was a sensible reason for the misinformation. Did it have nothing of the sort? A microkernel-like component in center of monolith like NT? Microkernel architecture with key stuff in kernel mode for performance like hybrids do? Did you see anything fitting the term in any BeOS release? And how would you classify its architecture?
- waddlesplash 9y agoI'd classify the BeOS kernel as a modular-ish monolithic kernel. I'm a bit fuzzy on some of the more precise details, like the network stack (which they rewrote 3 or 4 times...) but I know that all drivers, at least, ran in ring 0. Haiku's kernel is also monolithic, although we have a few hybrid tendencies (FUSE, but it's not widely used) and even more modularity than BeOS had, but we are still mostly source-compatible with the BeOS kernel. I don't know why people say it's a microkernel; people say the same of Haiku, but it's just not the case. Perhaps it's because the dynamic kernel module system is built-in and virtually all kernel modules are stored as shared objects and loaded on startup, vs. Linux's more static approach, at least historically? That's not at all what's meant by the term "monolithic", but popular perception is often wrong...
- nickpsecurity 9y agoAlright, that makes sense. I even suspected key drivers were in kernel mode given the performance on its kind of hardware. They might be saying it just because they don't know what a microkernel is. It might also be some new usage based on smaller, more-efficient kernels like used in containers. Who knows.