On Fri, Jan 22, 2021 at 4:44 PM KP Singh <kpsingh@xxxxxxxxxx> wrote: > > The script runs the BPF selftests locally on the same kernel image > as they would run post submit in the BPF continuous integration > framework. > > The goal of the script is to allow contributors to run selftests locally > in the same environment to check if their changes would end up breaking > the BPF CI and reduce the back-and-forth between the maintainers and the > developers. > > Signed-off-by: KP Singh <kpsingh@xxxxxxxxxx> > --- This is great, thanks a lot for working on this! This is great especially for ad-hoc contributors who don't have qemu workflow setup. Below are some comments for the extra polish :) 1. There is this long list output at the beginning: https://libbpf-vmtest.s3-us-west-1.amazonaws.com/x86_64/vmlinux-5.5.0.zst https://libbpf-vmtest.... Can we omit that? 2. Then something is re-downloaded every single time: % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 77713 100 77713 0 0 509k 0 --:--:-- --:--:-- --:--:-- 512k Unless it's to check if something newer appeared in S3, would be nice to skip that step. 3. Every single time I run the script it actually rebuilds kernel. Somehow Linux Makefile's logic to do nothing if nothing changed in Linux source code doesn't kick in, I wonder why? It's quite annoying and time-consuming for frequent selftest reruns. What's weird is that individual .o's are not re-built, but kernel is still re-linked and BTF is re-generated, which is the slow part :( 4. Selftests are re-built from scratch every single time, even if nothing changed. Again, strange because they won't do it normally. And given there is a fixed re-usable .bpf_selftests "cache directory", we should be able to set everything up so that no extra compilation is performed, no? 5. Before VM is started there is: #!/bin/bash { cd /root/bpf echo ./test_progs ./test_progs } 2>&1 | tee /root/bpf_selftests.2021-01-25_17-56-11.log poweroff -f Which is probably useful in rare cases for debugging purposes, but is just distracting in common case. Would it be able to have verbose flag for your script that would omit output like this by default? 6. Was too lazy to check, but once VM boots and before specified command is run, there is a bunch of verbose script echoing: + for path in /etc/rcS.d/S* If that's part of libbpf CI's image, let's fix it there. If not, let's fix it in your script? 7. Is it just me, or when ./test_progs is run inside VM, it's output is somehow heavily buffered and delayed? I get no output for a while, and then a whole bunch of lines with already passed tests. Curious if anyone else noticed that as well. When I run the same image locally and manually (not through your script), I don't have this issue. 8. I noticed that even if the command succeeds (e.g., ./test_progs in my case), the script exits with non-zero error code (32 in my case). That's suboptimal, because you can't use that script to detect test failures. But again, it's the polish feedback, great work! > tools/testing/selftests/bpf/run_in_vm.sh | 353 +++++++++++++++++++++++ > 1 file changed, 353 insertions(+) > create mode 100755 tools/testing/selftests/bpf/run_in_vm.sh > > diff --git a/tools/testing/selftests/bpf/run_in_vm.sh b/tools/testing/selftests/bpf/run_in_vm.sh > new file mode 100755 > index 000000000000..09bb9705acb3 > --- /dev/null > +++ b/tools/testing/selftests/bpf/run_in_vm.sh > @@ -0,0 +1,353 @@ > +#!/bin/bash > +# SPDX-License-Identifier: GPL-2.0 > + > +set -u > +set -e > + > +QEMU_BINARY="${QEMU_BINARY:="qemu-system-x86_64"}" > +X86_BZIMAGE="arch/x86/boot/bzImage" Might be worth it to mention that this only works with x86_64 (due to image restrictions at least, right?). > +DEFAULT_COMMAND="./test_progs" > +MOUNT_DIR="mnt" > +ROOTFS_IMAGE="root.img" > +OUTPUT_DIR="$HOME/.bpf_selftests" > +KCONFIG_URL="https://raw.githubusercontent.com/libbpf/libbpf/master/travis-ci/vmtest/configs/latest.config"; > +INDEX_URL="https://raw.githubusercontent.com/libbpf/libbpf/master/travis-ci/vmtest/configs/INDEX"; > +NUM_COMPILE_JOBS="$(nproc)" > + > +usage() > +{ > + cat <<EOF > +Usage: $0 [-k] [-i] [-d <output_dir>] -- [<command>] > + > +<command> is the command you would normally run when you are in > +tools/testing/selftests/bpf. e.g: > + > + $0 -- ./test_progs -t test_lsm > + > +If no command is specified, "${DEFAULT_COMMAND}" will be run by > +default. > + > +If you build your kernel using KBUILD_OUTPUT= or O= options, these > +can be passed as environment variables to the script: > + > + O=<path_relative_to_cwd> $0 -- ./test_progs -t test_lsm "relative_to_cwd" is a bit misleading, it could be an absolute path as well, I presume. So I'd just say "O=<kernel_build_path>" or something along those lines. > + > +or > + > + KBUILD_OUTPUT=<path_relative_to_cwd> $0 -- ./test_progs -t test_lsm > + [...]
