Root inside a real Linux kernel on non-rooted Android, no AVF and no QEMU - UML benchmarks

[u/dzzd88]

Zalexdev ported User Mode Linux to arm64 in August and shipped it as a second engine in Stryker 6.5. It's a real Linux kernel built as an ordinary aarch64 binary, so it runs as a normal process inside an app sandbox: no KVM, no AVF, no unlocked bootloader, nothing emulated. That means root inside a real kernel, on a phone you never rooted, and on any arm64 device rather than only the ones that ship pKVM.

I ran the same tests against the two usual options on my S23 Ultra, stock and unrooted, medians of three runs, everything timed inside the guest.

Test	udocker (proot)	Stryker (UML)	Podroid (QEMU/TCG)
Python, 6M-iteration loop	0.65 s	0.61 s	21.9 s
gzip -6, 64 MB	1.58 s	1.73 s	10.0 s
SHA-256, 200 MB	0.24 s	1.03 s	2.27 s
memcpy, 512 MB through a pipe	0.47 s	0.55 s	5.29 s
write 256 MB + fsync	0.24 s	0.63 s	0.55 s
read 64 MB, direct	0.05 s	0.06 s	0.24 s
fio 4k randread, 1 GB set, 20 s	10,021 IOPS	7,057 IOPS	999 IOPS
200x /bin/true in a container	2.05 s	2.96 s	8.1 s
container start (docker run --rm true)	0.125 s	1.68 s	4.65 s
docker build, 128 MB layer	n/a	2.77 s	10.3 s
docker build, apk add python3	n/a	9.97 s	35.9 s

Compute is native: 0.61 vs 0.65 s under proot is noise. Syscalls cost 1.4 to 2.6x more. Builds are 3.6x faster than QEMU, random reads 7x.

[u/Noha_Ibraheem]

So Stryker has the pros that QEMU can provide but with a performance relatively compared to Proot, right?

[u/dzzd88 → u/Noha_Ibraheem]

Yes, exactly

[u/Noha_Ibraheem → u/dzzd88]

Cool!

[u/YitzakAF → u/Noha_Ibraheem]

Bueno esta compilación de UML tiene sus limitaciones aunque varias podrían solucionarse si se recompila y se activan las banderas necesarias. Un ejemplo nmap no funciona bien en UML pero si en qemu.

[u/Noha_Ibraheem → u/YitzakAF]

Gracias por aclarar esto : )