nix-super/tests/compute-levels.sh

source common.sh

if [[ $(uname -ms) = "Linux x86_64" ]]; then
    # x86_64 CPUs must always support the baseline
    # microarchitecture level.
    nix -vv --version | grepQuiet "x86_64-v1-linux"
fi
Add x86_64 compute levels as additional system types When performing distributed builds of machine learning packages, it would be nice if builders without the required SIMD instructions can be excluded as build nodes. Since x86_64 has accumulated a large number of different instruction set extensions, listing all possible extensions would be unwieldy. AMD, Intel, Red Hat, and SUSE have recently defined four different microarchitecture levels that are now part of the x86-64 psABI supplement and will be used in glibc 2.33: https://gitlab.com/x86-psABIs/x86-64-ABI https://lwn.net/Articles/844831/ This change uses libcpuid to detect CPU features and then uses them to add the supported x86_64 levels to the additional system types. For example on a Ryzen 3700X: $ ~/aps/bin/nix -vv --version \| grep "Additional system" Additional system types: i686-linux, x86_64-v1-linux, x86_64-v2-linux, x86_64-v3-linux 2021-02-16 15:32:12 +02:00			`source common.sh`

			`if [[ $(uname -ms) = "Linux x86_64" ]]; then`
			`# x86_64 CPUs must always support the baseline`
			`# microarchitecture level.`
Harden tests' bash Use `set -u` and `set -o pipefail` to catch accidental mistakes and failures more strongly. - `set -u` catches the use of undefined variables - `set -o pipefail` catches failures (like `set -e`) earlier in the pipeline. This makes the tests a bit more robust. It is nice to read code not worrying about these spurious success paths (via uncaught) errors undermining the tests. Indeed, I caught some bugs doing this. There are a few tests where we run a command that should fail, and then search its output to make sure the failure message is one that we expect. Before, since the `grep` was the last command in the pipeline the exit code of those failing programs was silently ignored. Now with `set -o pipefail` it won't be, and we have to do something so the expected failure doesn't accidentally fail the test. To do that we use `expect` and a new `expectStderr` to check for the exact failing exit code. See the comments on each for why. `grep -q` is replaced with `grepQuiet`, see the comments on that function for why. `grep -v` when we just want the exit code is replaced with `grepInverse, see the comments on that function for why. `grep -q -v` together is, surprise surprise, replaced with `grepQuietInverse`, which is both combined. Co-authored-by: Robert Hensing <roberth@users.noreply.github.com> 2021-12-09 17:26:46 +02:00			`nix -vv --version \| grepQuiet "x86_64-v1-linux"`
Add x86_64 compute levels as additional system types When performing distributed builds of machine learning packages, it would be nice if builders without the required SIMD instructions can be excluded as build nodes. Since x86_64 has accumulated a large number of different instruction set extensions, listing all possible extensions would be unwieldy. AMD, Intel, Red Hat, and SUSE have recently defined four different microarchitecture levels that are now part of the x86-64 psABI supplement and will be used in glibc 2.33: https://gitlab.com/x86-psABIs/x86-64-ABI https://lwn.net/Articles/844831/ This change uses libcpuid to detect CPU features and then uses them to add the supported x86_64 levels to the additional system types. For example on a Ryzen 3700X: $ ~/aps/bin/nix -vv --version \| grep "Additional system" Additional system types: i686-linux, x86_64-v1-linux, x86_64-v2-linux, x86_64-v3-linux 2021-02-16 15:32:12 +02:00			`fi`