Does anyone more familiar with Hurd know how they addressed performance issues encountered by other Mach-based kernels? I remember reading that one of Mach's bottlenecks was validating that each IPC message had proper permissions/access when sending them between processes due to the large number and frequency of messages.

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glhaynes 20 minutes ago | parent | next [-]

Is there reason to think they've addressed them?

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floxy an hour ago | parent | prev [-]

Is that a bottleneck anymore? Maybe something that was appreciable in 1994 isn't a big performance hit in 2026?

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Analemma_ 32 minutes ago | parent [-]

Isn't it even worse now? The faster computers get, the more that software-induced bottlenecks hurt.

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doubled112 8 minutes ago | parent | next [-]

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.

	▲	monocasa 2 minutes ago \| parent [-]
		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.

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Manozco 19 minutes ago | parent | prev [-]

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 )

	▲	monocasa a minute ago \| parent [-]
		I mean, every major arch has crypto specific acceleration instructions.