A NetBSD/amd64 guest can now boot in 18ms

alberth wrote: post #3

How does this compare to other BSDs? Wasn't there recently a lot of work to reduce the time on FreeBSD (and it's 20ms) https://www.usenix.org/publications/loginonline/freebsd-fire... .

This work is based on the FreeBSD work.

Re: A NetBSD/amd64 guest can now boot in 18ms

#5

Post by dchest » Tue, Jan 16, 2024, 5:14 PM UTC

alberth wrote: post #3

How does this compare to other BSDs? Wasn't there recently a lot of work to reduce the time on FreeBSD (and it's 20ms) https://www.usenix.org/publications/loginonline/freebsd-fire... .

"I think the fastest I got the FreeBSD kernel booting in Firecracker was 21 ms. NetBSD is now at 18 ms... I need to go back and address some more of the issues I noticed but didn't get around to fixing.

Anyone know what the current record for Linux is? Last I heard was ~50 ms."

- @cperciva at https://twitter.com/cperciva/status/1747270461095043532

Re: A NetBSD/amd64 guest can now boot in 18ms

#6

Post by alberth » Tue, Jan 16, 2024, 5:48 PM UTC

dchest wrote: post #5

alberth wrote: post #3

How does this compare to other BSDs? Wasn't there recently a lot of work to reduce the time on FreeBSD (and it's 20ms) https://www.usenix.org/publications/loginonline/freebsd-fire... .

"I think the fastest I got the FreeBSD kernel booting in Firecracker was 21 ms. NetBSD is now at 18 ms... I need to go back and address some more of the issues I noticed but didn't get around to fixing. Anyone know what the current record for Linux is? Last I heard was ~50 ms." - @cperciva at https://twitter.com/cperciva/status/1747270461095043532

> “I need to go back and address some more of the issues I noticed but didn't get around to fixing.”

I wonder if this is related to what Netflix found as a regression.

Starting at slide #18 below

https://people.freebsd.org/~gallatin/talks/OpenFest2023.pdf

Re: A NetBSD/amd64 guest can now boot in 18ms

#7

Post by myself248 » Tue, Jan 16, 2024, 6:30 PM UTC

[in mice]

Re: A NetBSD/amd64 guest can now boot in 18ms

#8

Post by csdvrx » Tue, Jan 16, 2024, 6:32 PM UTC

That's nice, personally it takes me about 400 ms to start a linux kernel with qemu (more time is spent by qemu initializing its network interfaces that starting the kernel and the init!)

I'll see which tricks can be reused on linux, as I'd love to cut that by 1 order of magnitude!

Re: A NetBSD/amd64 guest can now boot in 18ms

#9

Post by lateralux » Tue, Jan 16, 2024, 6:35 PM UTC

Very interesting

Re: A NetBSD/amd64 guest can now boot in 18ms

#10

Post by wang_li » Tue, Jan 16, 2024, 6:40 PM UTC

I'm curious as to why this isn't 0ms for a VM. The entire state of the system can be known ahead of time. Why does the kernel need to do any kind of dynamic initialization? Why aren't all data structures and variables statically assigned to proper values for the given VM. So at VM start up time it simply enters the main dispatch loop.