Comment by floxy
6 hours ago
Is that a bottleneck anymore? Maybe something that was appreciable in 1994 isn't a big performance hit in 2026?
6 hours ago
Is that a bottleneck anymore? Maybe something that was appreciable in 1994 isn't a big performance hit in 2026?
Yes, you want to do more IPC, its basically linear with the increase in performance. So the amount of overhead stays the same basically. At least in IPC benchmarks and those tend to be important.
Making that fast is fundamental to any OS.
So for an I/O heavy program like a web browser, what percentage of CPU time is spent in syscalls? Someone must have that data for Firefox. 1%? 10%? And then that moves to 1.1% (or 11%)? And then every other program is even less affected? Curious if anyone is in the know.
Isn't it even worse now? The faster computers get, the more that software-induced bottlenecks hurt.
I could see just powering through because modern hardware is fast enough to do so being an option.
Adding 20% to a 10 second operation is a lot longer on a wall clock than adding 20% to a 1 second operation.
Hurd is like 36 years old at this point. More like adding 20% to a 10 second operation, compared to adding 20% to a 10ms operation.
What even is a 20% delta in performance? Like a five year old difference in hardware design.
If I could get a micro kernel with a better security profile than Linux, that doesn’t sound so bad. I could easily be using a ten year old chip for my day to day browsing and probably wouldn’t notice.
If anything, Mach style IPC has gotten worse because of the greater overhead if kernel/user transitions. Spectre really did a number on context switching overhead.
People lost their shit when Spectre mitigations added 20% overhead to kernel calls though. Why wouldn't they do the same for microkernel overhead?
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I'm not a Hurd contributor ( or any OS kernel / library ).
I'm not sure this holds today. One example I can see is related to crypto. We used to have specific hardware for computing cryptography functions but it's now handled directly in standard hardware and the software has not evolved ( but it's been faster and faster to compute checksum functions )
I mean, every major arch has crypto specific acceleration instructions.