wasmtime / issue #4232 cargo test too slow in qemu. · git-wasmtime

Stream: git-wasmtime

Topic: wasmtime / issue #4232 cargo test too slow in qemu.

Wasmtime GitHub notifications bot (Jun 07 2022 at 02:46):

yuyang-ok opened issue #4232:

I want to test riscv64 backend, but the build is just to slow.
https://github.com/bytecodealliance/wasmtime/blob/main/cranelift/docs/testing.md

cargo

root@debian:~/projects/wasmtime# cargo version
cargo 1.63.0-nightly (38472bc19 2022-05-31)

qemu

yuyang@yuyang-vmwarevirtualplatform:~/debian-rv64/artifacts$ qemu-system-riscv64 --version
QEMU emulator version 6.2.0 (Debian 1:6.2+dfsg-2ubuntu6)
Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers

I don't know how to speed up the  test.

Wasmtime GitHub notifications bot (Jun 07 2022 at 03:00):

cfallin commented on issue #4232:

Hi @yuyang-ok, for clarity, are you running the compiler (cargo test command) inside a RISC-V emulated virtual machine? Or are you using the qemu emulator just to run the compiled binary, after cross-compiling?

There is some documentation here about how to cross-compile Wasmtime/Cranelift and set the right environment variables so that cargo test running on your native system can invoke just the test binaries under emulation.

That said, this isn't really an issue with Wasmtime -- emulation is known to be slow, and it's kind of a fundamental downside of the approach compared to native hardware -- so I'm going to close this issue now.

Wasmtime GitHub notifications bot (Jun 07 2022 at 03:01):

cfallin closed issue #4232:

I want to test riscv64 backend, but the build is just to slow.
https://github.com/bytecodealliance/wasmtime/blob/main/cranelift/docs/testing.md

cargo

root@debian:~/projects/wasmtime# cargo version
cargo 1.63.0-nightly (38472bc19 2022-05-31)

qemu

I don't know how to speed up the  test.

Wasmtime GitHub notifications bot (Jun 07 2022 at 05:52):

yuyang-ok commented on issue #4232:

I am just running the compiler (cargo test command) inside a RISC-V emulated.

Wasmtime GitHub notifications bot (Jun 07 2022 at 13:09):

alexcrichton commented on issue #4232:

One other thing to watch out for when running Wasmtime tests is that Wasmtime makes very large virtual address space reservations by default and if emulation doesn't do the right thing then this can be excessively slow. We do some tricks in CI to make this faster which if you're trying to run in emulation you may be interested in mirroring.

Last updated: Dec 23 2024 at 12:05 UTC